PlantBioInnovation
Follow
Find
3.8K views | +0 today
 
Scooped by Biswapriya Biswavas Misra
onto PlantBioInnovation
Scoop.it!

Endodermal ABA Signaling Promotes Lateral Root Quiescence during Salt Stress in Arabidopsis Seedlings

Endodermal ABA Signaling Promotes Lateral Root Quiescence during Salt Stress in Arabidopsis Seedlings | PlantBioInnovation | Scoop.it
Biswapriya Biswavas Misra's insight:
Abstract

The endodermal tissue layer is found in the roots of vascular plants and functions as a semipermeable barrier, regulating the transport of solutes from the soil into the vascular stream. As a gateway for solutes, the endodermis may also serve as an important site for sensing and responding to useful or toxic substances in the environment. Here, we show that high salinity, an environmental stress widely impacting agricultural land, regulates growth of the seedling root system through a signaling network operating primarily in the endodermis. We report that salt stress induces an extended quiescent phase in postemergence lateral roots (LRs) whereby the rate of growth is suppressed for several days before recovery begins. Quiescence is correlated with sustained abscisic acid (ABA) response in LRs and is dependent upon genes necessary for ABA biosynthesis, signaling, and transcriptional regulation. We use a tissue-specific strategy to identify the key cell layers where ABA signaling acts to regulate growth. In the endodermis, misexpression of the ABA insensitive1-1 mutant protein, which dominantly inhibits ABA signaling, leads to a substantial recovery in LR growth under salt stress conditions. Gibberellic acid signaling, which antagonizes the ABA pathway, also acts primarily in the endodermis, and we define the crosstalk between these two hormones. Our results identify the endodermis as a gateway with an ABA-dependent guard, which prevents root growth into saline environments.

more...
No comment yet.
PlantBioInnovation
Discovery and Invention Aspects of Plant Biology That Are Interesting, Innovative and Novel !
Your new post is loading...
Your new post is loading...
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Structure, evolution and functional inference on the Mildew Locus O (MLO) gene family in three cultivated Cucurbitaceae spp.

Structure, evolution and functional inference on the Mildew Locus O (MLO) gene family in three cultivated Cucurbitaceae spp. | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Abstract
Background

The powdery mildew disease affects thousands of plant species and arguably represents the major fungal threat for many Cucurbitaceae crops, including melon (Cucumis melo L.), watermelon (Citrullus lanatus L.) and zucchini (Cucurbita pepo L.). Several studies revealed that specific members of the Mildew Locus O (MLO) gene family act as powdery mildew susceptibility factors. Indeed, their inactivation, as the result of gene knock-out or knock-down, is associated with a peculiar form of resistance, referred to as mlo resistance.

Results

We exploited recently available genomic information to provide a comprehensive overview of the MLO gene family in Cucurbitaceae. We report the identification of 16 MLO homologs in C. melo, 14 in C. lanatus and 18 in C. pepo genomes. Bioinformatic treatment of data allowed phylogenetic inference and the prediction of several ortholog pairs and groups. Comparison with functionally characterized MLO genes and, in C. lanatus, gene expression analysis, resulted in the detection of candidate powdery mildew susceptibility factors. We identified a series of conserved amino acid residues and motifs that are likely to play a major role for the function of MLO proteins. Finally, we performed a codon-based evolutionary analysis indicating a general high level of purifying selection in the three Cucurbitaceae MLO gene families, and the occurrence of regions under diversifying selection in candidate susceptibility factors.

Conclusions

Results of this study may help to address further biological questions concerning the evolution and function of MLO genes. Moreover, data reported here could be conveniently used by breeding research, aiming to select powdery mildew resistant cultivars in Cucurbitaceae.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Co-linearity and divergence of the A subgenome of Brassica juncea compared with other Brassica species carrying different A subgenomes

Co-linearity and divergence of the A subgenome of Brassica juncea compared with other Brassica species carrying different A subgenomes | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Background

There are three basic Brassica genomes (A, B, and C) and three parallel sets of subgenomes distinguished in the diploid Brassica (i.e.: B. rapa, ArAr; B. nigra, BniBni; B. oleracea, CoCo) and the derived allotetraploid species (i.e.: B. juncea, AjAjBjBj; B. napus, AnAnCnCn; B. carinata, BcBcCcCc). To understand subgenome differentiation in B. juncea in comparison to other A genome-carrying Brassica species (B. rapa and B. napus), we constructed a dense genetic linkage map of B. juncea, and conducted population genetic analysis on diverse lines of the three A-genome carrying Brassica species using a genotyping-by-sequencing approach (DArT-seq).

Results

A dense genetic linkage map of B. juncea was constructed using an F2 population derived from Sichuan Yellow/Purple Mustard. The map included 3329 DArT-seq markers on 18 linkage groups and covered 1579 cM with an average density of two markers per cM. Based on this map and the alignment of the marker sequences with the physical genome of Arabidopsis thaliana, we observed strong co-linearity of the ancestral blocks among the different A subgenomes but also considerable block variation. Comparative analyses at the level of genome sequences of B. rapa and B. napus, and marker sequence anchored on the genetic map of B. juncea, revealed a total of 30 potential inversion events across large segments and 20 potential translocation events among the three A subgenomes. Population genetic analysis on 26 accessions of the three A genome-carrying Brassica species showed that the highest genetic distance were estimated when comparing Aj-An than between An-Ar and Aj-Ar subgenome pairs.

Conclusions

The development of the dense genetic linkage map of B. juncea with informative DArT-seq marker sequences and availability of the reference sequences of the Ar, and AnCn genomes allowed us to compare the A subgenome structure of B. juncea (Aj) . Our results suggest that strong co-linearity exists among the three A Brassica genomes (Ar, An and Aj) but with apparent subgenomic variation. Population genetic analysis on three A-genome carrying Brassica species support the idea that B. juncea has distinct genomic diversity, and/or evolved from a different A genome progenitor of B. napus.

Keywords
more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Early transcriptomic response to Fe supply in Fe-deficient tomato plants is strongly influenced by the nature of the chelating agent

Early transcriptomic response to Fe supply in Fe-deficient tomato plants is strongly influenced by the nature of the chelating agent | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Background

It is well known that in the rhizosphere soluble Fe sources available for plants are mainly represented by a mixture of complexes between the micronutrient and organic ligands such as carboxylates and phytosiderophores (PS) released by roots, as well as fractions of humified organic matter. The use by roots of these three natural Fe sources (Fe-citrate, Fe-PS and Fe complexed to water-extractable humic substances, Fe-WEHS) have been already studied at physiological level but the knowledge about the transcriptomic aspects is still lacking.

Results

The 59Fe concentration recorded after 24 h in tissues of tomato Fe-deficient plants supplied with 59Fe complexed to WEHS reached values about 2 times higher than those measured in response to the supply with Fe-citrate and Fe-PS. However, after 1 h no differences among the three Fe-chelates were observed considering the 59Fe concentration and the root Fe(III) reduction activity. A large-scale transcriptional analysis of root tissue after 1 h of Fe supply showed that Fe-WEHS modulated only two transcripts leaving the transcriptome substantially identical to Fe-deficient plants. On the other hand, Fe-citrate and Fe-PS affected 728 and 408 transcripts, respectively, having 289 a similar transcriptional behaviour in response to both Fe sources.

Conclusions

The root transcriptional response to the Fe supply depends on the nature of chelating agents (WEHS, citrate and PS). The supply of Fe-citrate and Fe-PS showed not only a fast back regulation of molecular mechanisms modulated by Fe deficiency but also specific responses due to the uptake of the chelating molecule. Plants fed with Fe-WEHS did not show relevant changes in the root transcriptome with respect to the Fe-deficient plants, indicating that roots did not sense the restored cellular Fe accumulation.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Network-Based Comparative Analysis of Arabidopsis Immune Responses to Golovinomyces orontii and Botrytis cinerea Infections

Network-Based Comparative Analysis of Arabidopsis Immune Responses to Golovinomyces orontii and Botrytis cinerea Infections | PlantBioInnovation | Scoop.it
A comprehensive exploration of common and specific plant responses to biotrophs and necrotrophs is necessary for a better understanding of plant immunity.
Biswapriya Biswavas Misra's insight:

A comprehensive exploration of common and specific plant responses to biotrophs and necrotrophs is necessary for a better understanding of plant immunity. Here, we compared the Arabidopsis defense responses evoked by the biotrophic fungus Golovinomyces orontii and the necrotrophic fungus Botrytis cinerea through integrative network analysis. Two time-course transcriptional datasets were integrated with an Arabidopsis protein-protein interaction (PPI) network to construct a G. orontii conditional PPI sub-network (gCPIN) and a B. cinerea conditional PPI sub-network (bCPIN). We found that hubs in gCPIN and bCPIN played important roles in disease resistance. Hubs in bCPIN evolved faster than hubs in gCPIN, indicating the different selection pressures imposed on plants by different pathogens. By analyzing the common network from gCPIN and bCPIN, we identified two network components in which the genes were heavily involved in defense and development, respectively. The co-expression relationships between interacting proteins connecting the two components were different under G. orontii and B. cinerea infection conditions. Closer inspection revealed that auxin-related genes were overrepresented in the interactions connecting these two components, suggesting a critical role of auxin signaling in regulating the different co-expression relationships. Our work may provide new insights into plant defense responses against pathogens with different lifestyles.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Quantitative characterization of genetic parts and circuits for plant synthetic biology

Quantitative characterization of genetic parts and circuits for plant synthetic biology | PlantBioInnovation | Scoop.it
Quantitative analysis of promoter-repressor pairs in plants will allow the design of predictable gene circuits in multicellular organisms.
Biswapriya Biswavas Misra's insight:

A powerful form of machine learning that enables computers to solve perceptual problems such as image and speech recognition is increasingly making an entry into the biological sciences. These deep-learning methods, such as deep artificial neural networks, use multiple processing layers to discover patterns and structure in very large data sets. Each layer learns a concept from the data that subsequent layers build on; the higher the level, the more abstract the concepts that are learned. Deep learning does not depend on prior data processing and automatically extracts features. To use a simple example, a deep neural network tasked with interpreting shapes would learn to recognize simple edges in the first layer and then add recognition of the more complex shapes composed of those edges in subsequent layers. There is no hard and fast rule for how many layers are needed to constitute deep learning, but most experts agree that more than two are required.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

iRDA: a new filter towards predictive, stable, and enriched candidate genes

iRDA: a new filter towards predictive, stable, and enriched candidate genes | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Abstract
Background

Gene expression profiling using high-throughput screening (HTS) technologies allows clinical researchers to find prognosis gene signatures that could better discriminate between different phenotypes and serve as potential biological markers in disease diagnoses. In recent years, many feature selection methods have been devised for finding such discriminative genes, and more recently information theoretic filters have also been introduced for capturing feature-to-class relevance and feature-to-feature correlations in microarray-based classification.

Methods

In this paper, we present and fully formulate a new multivariate filter, iRDA, for the discovery of HTS gene-expression candidate genes. The filter constitutes a four-step framework and includes feature relevance, feature redundancy, and feature interdependence in the context of feature-pairs. The method is based upon approximate Markov blankets, information theory, several heuristic search strategies with forward, backward and insertion phases, and the method is aiming at higher order gene interactions.

Results

To show the strengths of iRDA, three performance measures, two evaluation schemes, two stability index sets, and the gene set enrichment analysis (GSEA) are all employed in our experimental studies. Its effectiveness has been validated by using seven well-known cancer gene-expression benchmarks and four other disease experiments, including a comparison to three popular information theoretic filters. In terms of classification performance, candidate genes selected by iRDA perform better than the sets discovered by the other three filters. Two stability measures indicate that iRDA is the most robust with the least variance. GSEA shows that iRDA produces more statistically enriched gene sets on five out of the six benchmark datasets.

Conclusions

Through the classification performance, the stability performance, and the enrichment analysis, iRDA is a promising filter to find predictive, stable, and enriched gene-expression candidate genes.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Construction of relatedness matrices using genotyping-by-sequencing data

Construction of relatedness matrices using genotyping-by-sequencing data | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Abstract
Background

Genotyping-by-sequencing (GBS) is becoming an attractive alternative to array-based methods for genotyping individuals for a large number of single nucleotide polymorphisms (SNPs). Costs can be lowered by reducing the mean sequencing depth, but this results in genotype calls of lower quality. A common analysis strategy is to filter SNPs to just those with sufficient depth, thereby greatly reducing the number of SNPs available. We investigate methods for estimating relatedness using GBS data, including results of low depth, using theoretical calculation, simulation and application to a real data set.

Results

We show that unbiased estimates of relatedness can be obtained by using only those SNPs with genotype calls in both individuals. The expected value of this estimator is independent of the SNP depth in each individual, under a model of genotype calling that includes the special case of the two alleles being read at random. In contrast, the estimator of self-relatedness does depend on the SNP depth, and we provide a modification to provide unbiased estimates of self-relatedness. We refer to these methods of estimation as kinship using GBS with depth adjustment (KGD). The estimators can be calculated using matrix methods, which allow efficient computation. Simulation results were consistent with the methods being unbiased, and suggest that the optimal sequencing depth is around 2–4 for relatedness between individuals and 5–10 for self-relatedness. Application to a real data set revealed that some SNP filtering may still be necessary, for the exclusion of SNPs which did not behave in a Mendelian fashion. A simple graphical method (a ‘fin plot’) is given to illustrate this issue and to guide filtering parameters.

Conclusion

We provide a method which gives unbiased estimates of relatedness, based on SNPs assayed by GBS, which accounts for the depth (including zero depth) of the genotype calls. This allows GBS to be applied at read depths which can be chosen to optimise the information obtained. SNPs with excess heterozygosity, often due to (partial) polyploidy or other duplications can be filtered based on a simple graphical method.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Genome-wide analysis of the basic leucine zipper (bZIP) transcription factor gene family in six legume genomes

Genome-wide analysis of the basic leucine zipper (bZIP) transcription factor gene family in six legume genomes | PlantBioInnovation | Scoop.it
Abstract
Background

Plant bZIP proteins characterist
Biswapriya Biswavas Misra's insight:
Abstract
Background

Plant bZIP proteins characteristically harbor a highly conserved bZIP domain with two structural features: a DNA-binding basic region and a leucine (Leu) zipper dimerization region. They have been shown to be diverse transcriptional regulators, playing crucial roles in plant development, physiological processes, and biotic/abiotic stress responses. Despite the availability of six completely sequenced legume genomes, a comprehensive investigation of bZIP family members in legumes has yet to be presented.

Results

In this study, we identified 428 bZIP genes encoding 585 distinct proteins in six legumes, Glycine max, Medicago truncatula, Phaseolus vulgaris, Cicer arietinum, Cajanus cajan, and Lotus japonicus. The legume bZIP genes were categorized into 11 groups according to their phylogenetic relationships with genes from Arabidopsis. Four kinds of intron patterns (a–d) within the basic and hinge regions were defined and additional conserved motifs were identified, both presenting high group specificity and supporting the group classification. We predicted the DNA-binding patterns and the dimerization properties, based on the characteristic features in the basic and hinge regions and the Leu zipper, respectively, which indicated that some highly conserved amino acid residues existed across each major group. The chromosome distribution and analysis for WGD-derived duplicated blocks revealed that the legume bZIP genes have expanded mainly by segmental duplication rather than tandem duplication. Expression data further revealed that the legume bZIP genes were expressed constitutively or in an organ-specific, development-dependent manner playing roles in multiple seed developmental stages and tissues. We also detected several key legume bZIP genes involved in drought- and salt-responses by comparing fold changes of expression values in drought-stressed or salt-stressed roots and leaves.

Conclusions

In summary, this genome-wide identification, characterization and expression analysis of legume bZIP genes provides valuable information for understanding the molecular functions and evolution of the legume bZIP transcription factor family, and highlights potential legume bZIP genes involved in regulating tissue development and abiotic stress responses.

 
more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

The Activation of Phytophthora Effector Avr3b by Plant Cyclophilin is Required for the Nudix Hydrolase Activity of Avr3b

The Activation of  Phytophthora  Effector Avr3b by Plant Cyclophilin is Required for the Nudix Hydrolase Activity of Avr3b | PlantBioInnovation | Scoop.it
Author Summary Phytophthora sojae , an oomycete pathogen that causes the Phytophthora root and stem rot disease of soybean, delivers variety of effectors into host cell to reprogram host immunity. Genome sequencing uncovers that P . sojae genome encode several hundreds of effector genes. However, the mode of action of most of the P . sojae effectors remains unknown. The investigation of effector-interacting proteins provides opportunities to better understand the pathogenesis mechani
Biswapriya Biswavas Misra's insight:

Plant pathogens secrete an arsenal of effector proteins to impair host immunity. Some effectors possess enzymatic activities that can modify their host targets. Previously, we demonstrated that a Phytophthora sojae RXLR effector Avr3b acts as a Nudix hydrolase when expressed in planta; and this enzymatic activity is required for full virulence of P. sojae strain P6497 in soybean (Glycine max). Interestingly, recombinant Avr3b produced by E. coli does not have the hydrolase activity unless it was incubated with plant protein extracts. Here, we report the activation of Avr3b by a prolyl-peptidyl isomerase (PPIase), cyclophilin, in plant cells. Avr3b directly interacts with soybean cyclophilin GmCYP1, which activates the hydrolase activity of Avr3b in a PPIase activity-dependent manner. Avr3b contains a putative Glycine-Proline (GP) motif; which is known to confer cyclophilin-binding in other protein substrates. Substitution of the Proline (P132) in the putative GP motif impaired the interaction of Avr3b with GmCYP1; as a result, the mutant Avr3bP132A can no longer be activated by GmCYP1, and is also unable to promote Phytophthora infection. Avr3b elicits hypersensitive response (HR) in soybean cultivars producing the resistance protein Rps3b, but Avr3bP132A lost its ability to trigger HR. Furthermore, silencing of GmCYP1 rendered reduced cell death triggered by Avr3b, suggesting that GmCYP1-mediated Avr3b maturation is also required for Rps3b recognition. Finally, cyclophilins of Nicotiana benthamiana can also interact with Avr3b and activate its enzymatic activity. Overall, our results demonstrate that cyclophilin is a “helper” that activates the enzymatic activity of Avr3b after it is delivered into plant cells; as such, cyclophilin is required for the avirulence and virulence functions of Avr3b.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Immunity to plant pathogens and iron homeostasis

Immunity to plant pathogens and iron homeostasis | PlantBioInnovation | Scoop.it
Iron is essential for metabolic processes in most living organisms. Pathogens and their hosts often compete for the acquisition of this nutrient. However, iron can catalyze the formation of deleterious reactive oxygen species. Hosts may use iron to increase local oxidative stress in defense responses against pathogens. Due to this duality, iron plays a complex role in plant-pathogen interactions. Plant defenses against pathogens and plant response to iron deficiency share several features, such as secretion of phenolic compounds, and use common hormone signaling pathways. Moreover, fine tuning of iron localization during infection involves genes coding iron transport and iron storage proteins, which have been shown to contribute to immunity. The influence of the plant iron status on the outcome of a given pathogen attack is strongly dependent on the nature of the pathogen infection strategy and on the host species. Microbial siderophores emerged as important factors as they have the ability to trigger plant defense responses. Depending on the plant species, siderophore perception can be mediated by their strong iron scavenging capacity or possibly via specific recognition as pathogen associated molecular patterns. This review highlights that iron has a key role in several plant-pathogen interactions by modulating immunity.
Biswapriya Biswavas Misra's insight:

Iron is essential for metabolic processes in most living organisms. Pathogens and their hosts often compete for the acquisition of this nutrient. However, iron can catalyze the formation of deleterious reactive oxygen species. Hosts may use iron to increase local oxidative stress in defense responses against pathogens. Due to this duality, iron plays a complex role in plant-pathogen interactions. Plant defenses against pathogens and plant response to iron deficiency share several features, such as secretion of phenolic compounds, and use common hormone signaling pathways. Moreover, fine tuning of iron localization during infection involves genes coding iron transport and iron storage proteins, which have been shown to contribute to immunity. The influence of the plant iron status on the outcome of a given pathogen attack is strongly dependent on the nature of the pathogen infection strategy and on the host species. Microbial siderophores emerged as important factors as they have the ability to trigger plant defense responses. Depending on the plant species, siderophore perception can be mediated by their strong iron scavenging capacity or possibly via specific recognition as pathogen associated molecular patterns. This review highlights that iron has a key role in several plant-pathogen interactions by modulating immunity.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Population History and Pathways of Spread of the Plant Pathogen Phytophthora plurivora

Population History and Pathways of Spread of the Plant Pathogen  Phytophthora plurivora | PlantBioInnovation | Scoop.it
Human activity has been shown to considerably affect the spread of dangerous pests and pathogens worldwide. Therefore, strict regulations of international trade exist for particularly harmful pathogenic organisms. Phytophthora plurivora, which is not subject to regulations, is a plant pathogen frequently found on a broad range of host species, both in natural and artificial environments. It is supposed to be native to Europe while resident populations are also present in the US. We characteri
Biswapriya Biswavas Misra's insight:

Human activity has been shown to considerably affect the spread of dangerous pests and pathogens worldwide. Therefore, strict regulations of international trade exist for particularly harmful pathogenic organisms. Phytophthora plurivora, which is not subject to regulations, is a plant pathogen frequently found on a broad range of host species, both in natural and artificial environments. It is supposed to be native to Europe while resident populations are also present in the US. We characterized a hierarchical sample of isolates from Europe and the US and conducted coalescent-, migration, and population genetic analysis of sequence and microsatellite data, to determine the pathways of spread and the demographic history of this pathogen. We found P. plurivora populations to be moderately diverse but not geographically structured. High levels of gene flow were observed within Europe and unidirectional from Europe to the US. Coalescent analyses revealed a signal of a recent expansion of the global P. plurivora population. Our study shows that P. plurivora has most likely been spread around the world by nursery trade of diseased plant material. In particular, P. plurivora was introduced into the US from Europe. International trade has allowed the pathogen to colonize new environments and/or hosts, resulting in population growth.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Worse Comes to Worst: Bananas and Panama Disease—When Plant and Pathogen Clones Meet

Worse Comes to Worst: Bananas and Panama Disease—When Plant and Pathogen Clones Meet | PlantBioInnovation | Scoop.it
more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

LONELY-GUY Knocks Every Door: Crosskingdom Microbial Pathogenesis

LONELY-GUY Knocks Every Door: Crosskingdom Microbial Pathogenesis | PlantBioInnovation | Scoop.it
Many plant microbial pathogens utilize cytokinins to establish interactions with their host. However, the production of cytokinins by an animal pathogen has just been reported for the first time. Here we discuss the impact of microbial secreted cytokinins on the infection dynamics in plant and animal cells.
more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Genome-wide discovery and validation of Eucalyptus small RNAs reveals variable patterns of conservation and diversity across species of Myrtaceae

Genome-wide discovery and validation of Eucalyptus small RNAs reveals variable patterns of conservation and diversity across species of Myrtaceae | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Background

Micro RNAs are a class of small non coding RNAs of 20–24 nucleotides transcribed as single stranded precursors from MIR gene loci. Initially described as post-transcriptional regulators involved in development, two decades ago, miRNAs have been proven to regulate a wide range of processes in plants such as germination, morphology and responses to biotic and abiotic stress. Despite wide conservation in plants, a number of miRNAs are lineage specific. We describe the first genome wide survey of Eucalyptus miRNAs based on high throughput sequencing.

Results

In addition to discovering small RNA sequences, MIR loci were mapped onto the reference genome and interspecific variability investigated. Sequencing was carried out for the two most world widely planted species, E. grandis and E. globulus. To maximize discovery, E. grandis samples were from BRASUZ1, the same tree whose genome provided the reference sequence. Interspecific analysis reinforces the variability in small RNA repertoire even between closely related species. Characterization of Eucalyptus small RNA sequences showed 95 orthologous to conserved miRNAs and 193 novel miRNAs. In silico target prediction confirmed 163 novel miRNAs and degradome sequencing experimentally confirmed several hundred targets. Experimental evidence based on the exclusive expression of a set of small RNAs across 16 species within Myrtaceae further highlighted variable patterns of conservation and diversity of these regulatory elements.

Conclusions

The description of miRNAs in Eucalyptus contributes to scientific knowledge of this vast genre, which is the most widely planted hardwood crop in the tropical and subtropical world, adding another important element to the annotation of Eucalyptus grandis reference genome.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Comparative transcriptional profiling of orange fruit in response to the biocontrol yeast Kloeckera apiculata and its active compounds

Comparative transcriptional profiling of orange fruit in response to the biocontrol yeast Kloeckera apiculata and its active compounds | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Background

The yeast Kloeckera apiculata strain 34–9 is an antagonist that shows biological control activity against the postharvest fungal pathogens of citrus. An antifungal compound, 2-phenylethanol (PEA), has been identified from the extract of K. apiculata. To better understand the molecular processes underlying the response of citrus fruit tissue to K. apiculata, the extract and PEA, microarray analyses were performed on navel oranges using an Affymetrix Citrus GeneChip.

Results

As many as 801, 339 and 608 differentially expressed genes (DEGs) were identified after the application of K. apiculata, the extract and PEA, respectively. In general, K. apiculata induced the expression of defence-related genes. In addition to chitinase and β-1,3-glucanase, genes involved in ethylene (ET), jasmonic acid (JA), calcium signalling, MAPK signalling and phenylalanine metabolism were induced. In contrast, monodehydroascorbate reductase, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and carotenoid biosynthesis genes were down-regulated. The expression profiles for the extract- and PEA-treated samples were similar to that found for yeast (sharing 57.4 % DEGs), with a significant increase in the transcript levels of defence-related genes.

Conclusion

This study provides a global picture of the gene expression changes in navel oranges after the application of the antagonist yeast K. apiculata, its extract and PEA. The interpretation of the DEGs revealed new insight into the molecular processes that regulate the defence responses in orange tissue.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

The Potato Nucleotide-binding Leucine-rich Repeat (NLR) Immune Receptor Rx1 Is a Pathogen-dependent DNA-deforming Protein

The Potato Nucleotide-binding Leucine-rich Repeat (NLR) Immune Receptor Rx1 Is a Pathogen-dependent DNA-deforming Protein | PlantBioInnovation | Scoop.it
Plant nucleotide-binding leucine-rich repeat (NLR) proteins enable cells to respond to pathogen attack. Several NLRs act in the nucleus; however, conserved nuclear targets that support their role in immunity are unknown. Previously, we noted a structural ...
Biswapriya Biswavas Misra's insight:

Plant nucleotide-binding leucine-rich repeat (NLR) proteins enable cells to respond to pathogen attack. Several NLRs act in the nucleus; however, conserved nuclear targets that support their role in immunity are unknown. Previously, we noted a structural homology between the nucleotide-binding domain of NLRs and DNA replication origin-binding Cdc6/Orc1 proteins. Here we show that the NB-ARC (nucleotide-binding, Apaf-1, R-proteins, and CED-4) domain of the Rx1 NLR of potato binds nucleic acids. Rx1 induces ATP-dependent bending and melting of DNA in vitro, dependent upon a functional P-loop. In situ full-length Rx1 binds nuclear DNA following activation by its cognate pathogen-derived effector protein, the coat protein of potato virus X. In line with its obligatory nucleocytoplasmic distribution, DNA binding was only observed when Rx1 was allowed to freely translocate between both compartments and was activated in the cytoplasm. Immune activation induced by an unrelated NLR-effector pair did not trigger an Rx1-DNA interaction. DNA binding is therefore not merely a consequence of immune activation. These data establish a role for DNA distortion in Rx1 immune signaling and define DNA as a molecular target of an activated NLR.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

LC-MS- and 1H NMR-Based Metabolomic Analysis and in Vitro Toxicological Assessment of 43 Aristolochia Species

LC-MS- and 1H NMR-Based Metabolomic Analysis and in Vitro Toxicological Assessment of 43 Aristolochia Species | PlantBioInnovation | Scoop.it
Species of Aristolochia are used as herbal medicines worldwide. They cause aristolochic acid nephropathy (AAN), a devastating disease associated with kidney failure and renal cancer. Aristolochic acids I and II (1 and 2) are considered to be responsible for these nephrotoxic and carcinogenic effects. A wide range of other aristolochic acid analogues (AAAs) exist, and their implication in AAN may have been overlooked. An LC-MS- and 1H NMR-based metabolomic analysis was carried out on 43 medicinally used Aristolochia species. The cytotoxicity and genotoxicity of 28 Aristolochia extracts were measured in human kidney (HK-2) cells. Compounds 1 and 2 were found to be the most common AAAs. However, AA IV (3), aristolactam I (4), and aristolactam BI (5) were also widespread. No correlation was found between the amounts of 1 or 2 and extract cytotoxicity against HK-2 cells. The genotoxicity and cytotoxicity of the extracts could be linked to their contents of 5, AA D (8), and AA IIIa (10). These results undermine the assumption that 1 and 2 are exclusively responsible for the toxicity of Aristolochia species. Other analogues are likely to contribute to their toxicity and need to be considered as nephrotoxic agents. These findings facilitate understanding of the nephrotoxic mechanisms of Aristolochia and have significance for the regulation of herbal medicines.
Biswapriya Biswavas Misra's insight:
Species of Aristolochia are used as herbal medicines worldwide. They cause aristolochic acid nephropathy (AAN), a devastating disease associated with kidney failure and renal cancer. Aristolochic acids I and II (1 and 2) are considered to be responsible for these nephrotoxic and carcinogenic effects. A wide range of other aristolochic acid analogues (AAAs) exist, and their implication in AAN may have been overlooked. An LC-MS- and 1H NMR-based metabolomic analysis was carried out on 43 medicinally used Aristolochia species. The cytotoxicity and genotoxicity of 28 Aristolochia extracts were measured in human kidney (HK-2) cells. Compounds 1 and 2 were found to be the most common AAAs. However, AA IV (3), aristolactam I (4), and aristolactam BI (5) were also widespread. No correlation was found between the amounts of 1 or 2 and extract cytotoxicity against HK-2 cells. The genotoxicity and cytotoxicity of the extracts could be linked to their contents of 5, AA D (8), and AA IIIa (10). These results undermine the assumption that 1 and 2 are exclusively responsible for the toxicity of Aristolochia species. Other analogues are likely to contribute to their toxicity and need to be considered as nephrotoxic agents. These findings facilitate understanding of the nephrotoxic mechanisms of Aristolochia and have significance for the regulation of herbal medicines.
more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Loss of function of folylpolyglutamate synthetase 1 reduces lignin content and improves cell wall digestibility in Arabidopsis

Loss of function of folylpolyglutamate synthetase 1 reduces lignin content and improves cell wall digestibility in Arabidopsis | PlantBioInnovation | Scoop.it
Biotechnology for Biofuels is an open access, peer-reviewed online journal featuring high-quality studies describing technological and operational advances in the production of biofuels, chemicals and other bioproducts from biomass. The journal emphasizes understanding and advancing the application of biotechnology and synergistic operations to improve plants and biological conversion systems for the production of fuels, chemicals and other bioproducts from biomass and any related economic, environmental and policy issues.
more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Population genomics of pearl millet (Pennisetum glaucum (L.) R. Br.): Comparative analysis of global accessions and Senegalese landraces

Population genomics of pearl millet (Pennisetum glaucum (L.) R. Br.): Comparative analysis of global accessions and Senegalese landraces | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Abstract
Background

Pearl millet is a staple food for people in arid and semi-arid regions of Africa and South Asia due to its high drought tolerance and nutritional qualities. A better understanding of the genomic diversity and population structure of pearl millet germplasm is needed to support germplasm conservation and genetic improvement of this crop. Here we characterized two pearl millet diversity panels, (i) a set of global accessions from Africa, Asia, and the America, and (ii) a collection of landraces from multiple agro-ecological zones in Senegal.

Results

We identified 83,875 single nucleotide polymorphisms (SNPs) in 500 pearl millet accessions, comprised of 252 global accessions and 248 Senegalese landraces, using genotyping by sequencing (GBS) of PstI-MspI reduced representation libraries. We used these SNPs to characterize genomic diversity and population structure among the accessions. The Senegalese landraces had the highest levels of genetic diversity (π), while accessions from southern Africa and Asia showed lower diversity levels. Principal component analyses and ancestry estimation indicated clear population structure between the Senegalese landraces and the global accessions, and among countries in the global accessions. In contrast, little population structure was observed across in the Senegalese landraces collections. We ordered SNPs on the pearl millet genetic map and observed much faster linkage disequilibrium (LD) decay in Senegalese landraces compared to global accessions. A comparison of pearl millet GBS linkage map with the foxtail millet (Setaria italica) and sorghum (Sorghum bicolor) genomes indicated extensive regions of synteny, as well as some large-scale rearrangements in the pearl millet lineage.

Conclusions

We identified 83,875 SNPs as a genomic resource for pearl millet improvement. The high genetic diversity in Senegal relative to other regions of Africa and Asia supports a West African origin of this crop, followed by wide diffusion. The rapid LD decay and lack of confounding population structure along agro-ecological zones in Senegalese pearl millet will facilitate future association mapping studies. Comparative population genomics will provide insights into panicoid crop evolution and support improvement of these climate-resilient crops.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Incorporation of subject-level covariates in quantile normalization of miRNA data

Incorporation of subject-level covariates in quantile normalization of miRNA data | PlantBioInnovation | Scoop.it
BMC Genomics is an open access journal publishing original peer-reviewed research articles in all aspects of genome-scale analysis, functional genomics, and proteomics. BMC Genomics is part of the BMC series which publishes subject-specific journals focused on the needs of individual research communities across all areas of biology and medicine. We offer an efficient, fair and friendly peer review service, and are committed to publishing all sound science, provided that there is some advance in knowledge presented by the work. BMC series - open, inclusive and trusted.
Biswapriya Biswavas Misra's insight:
Abstract
Background

Most currently-used normalization methods for miRNA array data are based on methods developed for mRNA arrays despite fundamental differences between the data characteristics. The application of conventional quantile normalization can mask important expression differences by ignoring demographic and environmental factors. We present a generalization of the conventional quantile normalization method, making use of available subject-level covariates in a colorectal cancer study.

Results

In simulation, our weighted quantile normalization method is shown to increase statistical power by as much as 10 % when relevant subject-level covariates are available. In application to the colorectal cancer study, this increase in power is also observed, and previously-reported dysregulated miRNAs are rediscovered.

Conclusions

When any subject-level covariates are available, the weighted quantile normalization method should be used over the conventional quantile normalization method.

Keywords
more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Assessing the Mismatch Between Incubation and Latent Periods for Vector-Borne Diseases: The Case of Sharka

Assessing the Mismatch Between Incubation and Latent Periods for Vector-Borne Diseases: The Case of Sharka | PlantBioInnovation | Scoop.it
Biswapriya Biswavas Misra's insight:

The relative durations of the incubation period (the time between inoculation and symptom expression) and of the latent period (the time between inoculation and infectiousness of the host) are poorly documented for plant diseases. However, the extent of asynchrony between the ends of these two periods (i.e., their mismatch) can be a key determinant of the epidemic dynamics for many diseases and consequently it is of primary interest in the design of disease management strategies. In order to assess this mismatch, an experimental approach was developed and applied using sharka, a severe disease caused by Plum pox virus (PPV, genus Potyvirus, family Potyviridae) affecting trees belonging to the genus Prunus. Leaves of infected young peach trees were used individually as viral sources in aphid-mediated transmission tests carried out at different time points postinoculation in order to bracket symptom onset. By fitting a nonlinear logistic model to the obtained transmission rates, we demonstrated that the first symptoms appear on leaves 1 day before they rapidly become infectious. In addition, among symptomatic leaves, symptom intensity and transmission rate are positively correlated. These results strengthen the conclusion that, under our experimental conditions, incubation and latent periods of PPV infection are almost synchronous.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

How eukaryotic filamentous pathogens evade plant recognition

How eukaryotic filamentous pathogens evade plant recognition | PlantBioInnovation | Scoop.it
Biswapriya Biswavas Misra's insight:

Plant pathogenic fungi and oomycetes employ sophisticated mechanisms for evading host recognition. After host penetration, many fungi and oomycetes establish a biotrophic interaction. It is assumed that different strategies employed by these pathogens to avoid triggering host defence responses, including establishment of biotrophic interfacial layers between the pathogen and host, masking of invading hyphae and active suppression of host defence mechanisms, are essential for a biotrophic parasitic lifestyle. During the infection process, filamentous plant pathogens secrete various effectors, which are hypothesized to be involved in facilitating effective host infection. Live-cell imaging of fungi and oomycetes secreting fluorescently labeled effector proteins as well as functional characterization of the components of biotrophic interfaces have led to the recent progress in understanding how eukaryotic filamentous pathogens evade plant recognition.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Genome Sequence and Architecture of the Tobacco Downy Mildew Pathogen Peronospora tabacina

Genome Sequence and Architecture of the Tobacco Downy Mildew Pathogen Peronospora tabacina | PlantBioInnovation | Scoop.it
Biswapriya Biswavas Misra's insight:

Peronospora tabacina is an obligate biotrophic oomycete that causes blue mold or downy mildew on tobacco (Nicotiana tabacum). It is an economically important disease occurring frequently in tobacco-growing regions worldwide. We sequenced and characterized the genomes of two P. tabacina isolates and mined them for pathogenicity-related proteins and effector-encoding genes. De novo assembly of the genomes using Illumina reads resulted in 4,016 (63.1 Mb, N50 = 79 kb) and 3,245 (55.3 Mb, N50 = 61 kb) scaffolds for isolates 968-J2 and 968-S26, respectively, with an estimated genome size of 68 Mb. The mitochondrial genome has a similar size (approximately 43 kb) and structure to those of other oomycetes, plus several minor unique features. Repetitive elements, primarily retrotransposons, make up approximately 24% of the nuclear genome. Approximately 18,000 protein-coding gene models were predicted. Mining the secretome revealed approximately 120 candidate RxLR, six CRN (candidate effectors that elicit crinkling and necrosis), and 61 WY domain–containing proteins. Candidate RxLR effectors were shown to be predominantly undergoing diversifying selection, with approximately 57% located in variable gene-sparse regions of the genome. Aligning the P. tabacina genome to Hyaloperonospora arabidopsidis and Phytophthora spp. revealed a high level of synteny. Blocks of synteny show gene inversions and instances of expansion in intergenic regions. Extensive rearrangements of the gene-rich genomic regions do not appear to have occurred during the evolution of these highly variable pathogens. These assemblies provide the basis for studies of virulence in this and other downy mildew pathogens.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Lactoferrin-Derived Resistance against Plant Pathogens in Transgenic Plants

Lactoferrin-Derived Resistance against Plant Pathogens in Transgenic Plants | PlantBioInnovation | Scoop.it
Transgenic
Biswapriya Biswavas Misra's insight:

Lactoferrin (LF) is a ubiquitous cationic iron-binding milk glycoprotein that contributes to nutrition and exerts a broad-spectrum primary defense against bacteria, fungi, protozoa, and viruses in mammals. These qualities make lactoferrin protein and its antimicrobial motifs highly desirable candidates to be incorporated in plants to impart broad-based resistance against plant pathogens or to economically produce them in bulk quantities for pharmaceutical and nutritional purposes. This study introduced bovine LF (BLF) gene into tobacco (Nicotiana tabacum var. Xanthi), Arabidopsis (A. thaliana) and wheat (Triticum aestivum) via Agrobacterium-mediated plant transformation. Transgenic plants or detached leaves exhibited high levels of resistance against the damping-off causing fungal pathogen Rhizoctonia solani and the head blight causing fungal pathogen Fusarium graminearum. LF also imparted resistance to tomato plants against a bacterial pathogen, Ralstonia solanacearum. Similarly, other researchers demonstrated expression of LF and LF-mediated high-quality resistance to several other aggressive fungal and bacterial plant pathogens in transgenic plants and against viral pathogens by foliar applications of LF or its derivatives. Taken together, these studies demonstrated the effectiveness of LF for improving crop quality and its biopharming potentials for pharmaceautical and nutritional applications.

more...
No comment yet.
Scooped by Biswapriya Biswavas Misra
Scoop.it!

Surveying the potential of secreted antimicrobial peptides to enhance plant disease resistance

Surveying the potential of secreted antimicrobial peptides to enhance plant disease resistance | PlantBioInnovation | Scoop.it
Antimicrobial peptides (AMPs) are natural products found across diverse taxa as part of the innate immune system against pathogen attacks. Some AMPs are synthesized through the canonical gene expression machinery and are called ribosomal AMPs. Other AMPs are assembled by modular enzymes generating nonribosomal AMPs and harbor unusual structural diversity. Plants synthesize an array of AMPs, yet are still subject to many pathogen invasions. Crop breeding programs struggle to release new cultivars in which complete disease resistance is achieved, and usually such resistance becomes quickly overcome by the targeted pathogens which have a shorter generation time. AMPs could offer a solution by exploring not only plant-derived AMPs, related or unrelated to the crop of interest, but also non-plant AMPs produced by bacteria, fungi, oomycetes or animals. This review highlights some promising candidates within the plant kingdom and elsewhere, and offers some perspectives on how to identify and validate their bioactivities. Technological advances, particularly in mass spectrometry (MS) and nuclear magnetic resonance (NMR), have been instrumental in identifying and elucidating the structure of novel AMPs, especially nonribosomal peptides which cannot be identified through genomics approaches. The majority of non-plant AMPs showing potential for plant disease immunity are often tested using in vitro assays. The greatest challenge remains the functional validation of candidate AMPs in plants through transgenic experiments, particularly introducing nonribosomal AMPs into crops.
Biswapriya Biswavas Misra's insight:

Antimicrobial peptides (AMPs) are natural products found across diverse taxa as part of the innate immune system against pathogen attacks. Some AMPs are synthesized through the canonical gene expression machinery and are called ribosomal AMPs. Other AMPs are assembled by modular enzymes generating nonribosomal AMPs and harbor unusual structural diversity. Plants synthesize an array of AMPs, yet are still subject to many pathogen invasions. Crop breeding programs struggle to release new cultivars in which complete disease resistance is achieved, and usually such resistance becomes quickly overcome by the targeted pathogens which have a shorter generation time. AMPs could offer a solution by exploring not only plant-derived AMPs, related or unrelated to the crop of interest, but also non-plant AMPs produced by bacteria, fungi, oomycetes or animals. This review highlights some promising candidates within the plant kingdom and elsewhere, and offers some perspectives on how to identify and validate their bioactivities. Technological advances, particularly in mass spectrometry (MS) and nuclear magnetic resonance (NMR), have been instrumental in identifying and elucidating the structure of novel AMPs, especially nonribosomal peptides which cannot be identified through genomics approaches. The majority of non-plant AMPs showing potential for plant disease immunity are often tested using in vitro assays. The greatest challenge remains the functional validation of candidate AMPs in plants through transgenic experiments, particularly introducing nonribosomal AMPs into crops.

more...
No comment yet.