Plant Gene Seeker -PGS
7.2K views | +0 today
 
Scooped by Andres Zurita
onto Plant Gene Seeker -PGS
Scoop.it!

Cell Wall, Cytoskeleton, and Cell Expansion in Higher Plants

Cell Wall, Cytoskeleton, and Cell Expansion in Higher Plants | Plant Gene Seeker -PGS | Scoop.it
Andres Zurita's insight:

To accommodate two seemingly contradictory biological roles in plant physiology, providing both the rigid structural support of plant cells and the adjustable elasticity needed for cell expansion, the composition of the plant cell wall has evolved to become an intricate network of cellulosic, hemicellulosic, and pectic polysaccharides and protein. Due to its complexity, many aspects of the cell wall influence plant cell expansion, and many new and insightful observations and technologies are forthcoming. The biosynthesis of cell wall polymers and the roles of the variety of proteins involved in polysaccharide synthesis continue to be characterized. The interactions within the cell wall polymer network and the modification of these interactions provide insight into how the plant cell wall provides its dual function. The complex cell wall architecture is controlled and organized in part by the dynamic intracellular cytoskeleton and by diverse trafficking pathways of the cell wall polymers and cell wall-related machinery. Meanwhile, the cell wall is continually influenced by hormonal and integrity sensing stimuli that are perceived by the cell. These many processes cooperate to construct, maintain, and manipulate the intricate plant cell wall—an essential structure for the sustaining of the plant stature, growth, and life.

more...
No comment yet.
Plant Gene Seeker -PGS
Absolutely Fascinated for plant & genomes
Curated by Andres Zurita
Your new post is loading...
Your new post is loading...
Scooped by Andres Zurita
Scoop.it!

The walnut (Juglans regia) genome sequence reveals diversity in genes coding for the biosynthesis of nonstructural polyphenols - Martínez-García - 2016 - The Plant Journal - Wiley Online Library

The walnut (Juglans regia) genome sequence reveals diversity in genes coding for the biosynthesis of nonstructural polyphenols - Martínez-García - 2016 - The Plant Journal - Wiley Online Library | Plant Gene Seeker -PGS | Scoop.it
The Persian walnut (Juglans regia L.) a diploid species native to the mountainous regions of Central Asia, is the major walnut species cultivated for nut production and is one of the most widespread tree nut species in the world. The high nutritional value of J. regia nuts is associated with a rich array of polyphenolic compounds, whose complete biosynthetic pathways are still unknown. A J. regia genome sequence was obtained from the cultivar Chandler to discover target genes and additional unknown genes. The 667 Mbp genome was assembled using two different methods (SOAPdenovo2 and MaSuRCA), with a N50 scaffold size of 464,955 bp (based on a 606 Mbp genome size), 221,640 contigs and 37% GC content. Annotation with MAKER-P and other genomic resources yielded 32,498 gene models. Previous studies in walnut relying on tissue-specific methods have only identified a single PPO gene (JrPPO1). Enabled by the J. regia genome sequence, a second homolog of PPO (JrPPO2) was discovered. In addition, ~130 genes in the large GGT superfamily were detected. Specifically, two genes, JrGGT1 and JrGGT2, were significantly homologous to the GGT from Quercus robur (QrGGT), which is involved in the synthesis of 1-O-galloyl-β-D-glucose, a precursor for the synthesis of hydrolysable tannins. The reference genome for J. regia provides meaningful insight into the complex pathways required for the synthesis of polyphenols. The walnut genome sequence provides important tools and methods to accelerate breeding and to facilitate the genetic dissection of complex traits.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Connecting Source with Sink: The Role of Arabidopsis AAP8 in Phloem Loading of Amino Acids

Connecting Source with Sink: The Role of Arabidopsis AAP8 in Phloem Loading of Amino Acids | Plant Gene Seeker -PGS | Scoop.it
Allocation of large amounts of nitrogen to developing organs occurs in the phloem and is essential for plant growth and seed development. In Arabidopsis (Arabidopsis thaliana) and many other plant species, amino acids represent the dominant nitrogen transport forms in the phloem, and they are mainly synthesized in photosynthetically active source leaves. Following their synthesis, a broad spectrum of the amino nitrogen is actively loaded into the phloem of leaf minor veins and transported within the phloem sap to sinks such as developing leaves, fruits, or seeds. Controlled regulation of the source-to-sink transport of amino acids has long been postulated; however, the molecular mechanism of amino acid phloem loading was still unknown. In this study, Arabidopsis AMINO ACID PERMEASE8 (AAP8) was shown to be expressed in the source leaf phloem and localized to the plasma membrane, suggesting its function in phloem loading. This was further supported by transport studies with aap8 mutants fed with radiolabeled amino acids and by leaf exudate analyses. In addition, biochemical and molecular analyses revealed alterations in leaf nitrogen pools and metabolism dependent on the developmental stage of the mutants. Decreased amino acid phloem loading and partitioning to sinks led to decreased silique and seed numbers, but seed protein levels were unchanged, demonstrating the importance of AAP8 function for sink development rather than seed quality. Overall, these results show that AAP8 plays an important role in source-to-sink partitioning of nitrogen and that its function affects source leaf physiology and seed yield.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Evolution of plant genome architecture

Evolution of plant genome architecture | Plant Gene Seeker -PGS | Scoop.it
Abstract

We have witnessed an explosion in our understanding of the evolution and structure of plant genomes in recent years. Here, we highlight three important emergent realizations: (1) that the evolutionary history of all plant genomes contains multiple, cyclical episodes of whole-genome doubling that were followed by myriad fractionation processes; (2) that the vast majority of the variation in genome size reflects the dynamics of proliferation and loss of lineage-specific transposable elements; and (3) that various classes of small RNAs help shape genomic architecture and function. We illustrate ways in which understanding these organism-level and molecular genetic processes can be used for crop plant improvement.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Crop Diversity: An Unexploited Treasure Trove for Food Security: Trends in Plant Science

Crop Diversity: An Unexploited Treasure Trove for Food Security: Trends in Plant Science | Plant Gene Seeker -PGS | Scoop.it
The prediction is that food supply must double by 2050 to cope with the impact of climate change and population pressure on global food systems. The diversification of staple crops and the systems in which they grow is essential to make future agriculture sustainable, resilient, and suitable for local environments and soils.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Joint genetic and network analyses identify loci associated with root growth under NaCl stress in Arabidopsis thaliana 

Joint genetic and network analyses identify loci associated with root growth under NaCl stress in Arabidopsis thaliana  | Plant Gene Seeker -PGS | Scoop.it
Plants have evolved a series of tolerance mechanisms to saline stress, which perturbs physiological processes throughout the plant. To identify genetic mechanisms associated with salinity tolerance, we performed linkage analysis and genome-wide association study (GWAS) on maintenance of root growth of Arabidopsis thaliana in hydroponic culture with weak and severe NaCl toxicity. The top 200 single-nucleotide polymorphisms (SNPs) determined by GWAS could cumulatively explain approximately 70% of the variation observed at each stress level. The most significant SNPs were linked to the genes of ATP-binding cassette B10 and vacuolar proton ATPase A2. Several known salinity tolerance genes such as potassium channel KAT1 and calcium sensor SOS3 were also linked to SNPs in the top 200. In parallel, we constructed a gene co-expression network to independently verify that particular groups of genes work together to a common purpose. We identify molecular mechanisms to confer salt tolerance from both predictable and novel physiological sources and validate the utility of combined genetic and network analysis. Additionally, our study indicates that the genetic architecture of salt tolerance is responsive to the severity of stress. These gene datasets are a significant information resource for a following exploration of gene function.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Online collaboration: Scientists and the social network

Online collaboration: Scientists and the social network | Plant Gene Seeker -PGS | Scoop.it
Giant academic social networks have taken off to a degree that no one expected even a few years ago. A Nature survey explores why.
Andres Zurita's insight:
An interesting trend! Don't stay off-line 
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Plants in silico: why, why now and what?—an integrative platform for plant systems biology research - Zhu - 2015 - Plant, Cell & Environment - Wiley Online Library

Plants in silico: why, why now and what?—an integrative platform for plant systems biology research - Zhu - 2015 - Plant, Cell & Environment - Wiley Online Library | Plant Gene Seeker -PGS | Scoop.it
A paradigm shift is needed and timely in moving plant modelling from largely isolated efforts to a connected community endeavour that can take full advantage of advances in computer science and in mechanistic understanding of plant processes. Plants in silico (Psi) envisions a digital representation of layered dynamic modules, linking from gene networks and metabolic pathways through to cellular organization, tissue, organ and whole plant development, together with resource capture and use efficiency in dynamic competitive environments, ultimately allowing a mechanistically rich simulation of the plant or of a community of plants in silico. The concept is to integrate models or modules from different layers of organization spanning from genome to phenome to ecosystem in a modular framework allowing the use of modules of varying mechanistic detail representing the same biological process. Developments in high-performance computing, functional knowledge of plants, the internet and open-source version controlled software make achieving the concept realistic. Open source will enhance collaboration and move towards testing and consensus on quantitative theoretical frameworks. Importantly, Psi provides a quantitative knowledge framework where the implications of a discovery at one level, for example, single gene function or developmental response, can be examined at the whole plant or even crop and natural ecosystem levels.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Yield responses in Flame seedless, Thompson seedless and Red Globe table grape cultivars are differentially modified by rootstocks under semi arid conditions

Abstract 
A field study was conducted during six seasons (2004–2009) to assess rootstocks effects over yield in three table grape cultivars (Thompson seedless, Flame seedless and Red Globe). Nine commercially available rootstocks (Couderc 1613, Freedom, Harmony, Paulsen 1103, Richter 99, Richter 110, Ruggeri 140, Saint George and Salt Creek) plus a control treatment (own-rooted vines) were evaluated under semiarid conditions of northern Chile. A multivariate analysis approach consisting of principal components analysis and cluster analysis was used to segregate those rootstocks with similar influence within each cultivar scion. Three significant clusters were found in Flame seedless and Thompson seedless, while Red Globe showed four significant clusters. Analysis of variance were conducted to evaluate differences in fruit yield, pruning weight, budburst, fruit set, bunch weight, berry weight, berry diameter and rachis weight between rootstock clusters. All rootstocks but Saint George increased yield in Flame seedless, while Salt Creek was the only rootstock with positive effects in Thompson seedless. The use of either Couderc 1613, Freedom, Harmony, Paulsen 1103 or Salt Creek was recommended in Red Globe. This is the first mid-term study with a multivariate analysis of yield components in three table grape cultivars evaluating nine rootstocks in semiarid conditions.
Andres Zurita's insight:
Nine rootstocks were evaluated simultaneously in three table grape cultivars throughout six seasons under semi arid conditions. • A multivariate approach was used to group those rootstocks with similar performance within each table grape cultivar. • The use of rootstocks has a differential result in yield depending on the cultivar to be used as a scion.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Genome Biology

Genome Biology | Plant Gene Seeker -PGS | Scoop.it
Background
Legumes are the third largest family of angiosperms and the second most important crop class. Legume genomes have been shaped by extensive large-scale gene duplications, including an approximately 58 million year old whole genome duplication shared by most crop legumes.

Results
We report the genome and the transcription atlas of coding and non-coding genes of a Mesoamerican genotype of common bean (Phaseolus vulgaris L., BAT93). Using a comprehensive phylogenomics analysis, we assessed the past and recent evolution of common bean, and traced the diversification of patterns of gene expression following duplication. We find that successive rounds of gene duplications in legumes have shaped tissue and developmental expression, leading to increased levels of specialization in larger gene families. We also find that many long non-coding RNAs are preferentially expressed in germ-line-related tissues (pods and seeds), suggesting that they play a significant role in fruit development. Our results also suggest that most bean-specific gene family expansions, including resistance gene clusters, predate the split of the Mesoamerican and Andean gene pools.

Conclusions
The genome and transcriptome data herein generated for a Mesoamerican genotype represent a counterpart to the genomic resources already available for the Andean gene pool. Altogether, this information will allow the genetic dissection of the characters involved in the domestication and adaptation of the crop, and their further implementation in breeding strategies for this important crop.
Andres Zurita's insight:
Background. Legumes are the third largest family of angiosperms and the second most important crop class. Legume genomes have been shaped by extensive large-scale gene duplications, including an approximately 58 million year old whole genome duplication shared by most crop legumes.
Results.  We report the genome and the transcription atlas of coding and non-coding genes of a Mesoamerican genotype of common bean (Phaseolus vulgaris L., BAT93). Using a comprehensive phylogenomics analysis, we assessed the past and recent evolution of common bean, and traced the diversification of patterns of gene expression following duplication. We find that successive rounds of gene duplications in legumes have shaped tissue and developmental expression, leading to increased levels of specialization in larger gene families. We also find that many long non-coding RNAs are preferentially expressed in germ-line-related tissues (pods and seeds), suggesting that they play a significant role in fruit development. Our results also suggest that most bean-specific gene family expansions, including resistance gene clusters, predate the split of the Mesoamerican and Andean gene pools. 
Conclusions. The genome and transcriptome data herein generated for a Mesoamerican genotype represent a counterpart to the genomic resources already available for the Andean gene pool. Altogether, this information will allow the genetic dissection of the characters involved in the domestication and adaptation of the crop, and their further implementation in breeding strategies for this important crop.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Constant change: dynamic regulation of membrane transport by calcium signalling networks keeps plants in tune with their environment

Constant change: dynamic regulation of membrane transport by calcium signalling networks keeps plants in tune with their environment | Plant Gene Seeker -PGS | Scoop.it
Andres Zurita's insight:

Despite substantial variation and irregularities in their environment, plants must conform to spatiotemporal demands on the molecular composition of their cytosol. Cell membranes are the major interface between organisms and their environment and the basis for controlling the contents and intracellular organization of the cell. Membrane transport proteins (MTPs) govern the flow of molecules across membranes, and their activities are closely monitored and regulated by cell signalling networks. By continuously adjusting MTP activities, plants can mitigate the effects of environmental perturbations, but effective implementation of this strategy is reliant on precise coordination among transport systems that reside in distinct cell types and membranes. Here, we examine the role of calcium signalling in the coordination of membrane transport, with an emphasis on potassium transport. Potassium is an exceptionally abundant and mobile ion in plants, and plant potassium transport has been intensively studied for decades. Classic and recent studies have underscored the importance of calcium in plant environmental responses and membrane transport regulation. In reviewing recent advances in our understanding of the coding and decoding of calcium signals, we highlight established and emerging roles of calcium signalling in coordinating membrane transport among multiple subcellular locations and distinct transport systems in plants, drawing examples from the CBL-CIPK signalling network. By synthesizing classical studies and recent findings, we aim to provide timely insights on the role of calcium signalling networks in the modulation of membrane transport and its importance in plant environmental responses.

more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Genome-Wide Detection of SNP and SV Variations to Reveal Early Ripening-Related Genes in Grape

Genome-Wide Detection of SNP and SV Variations to Reveal Early Ripening-Related Genes in Grape | Plant Gene Seeker -PGS | Scoop.it
Andres Zurita's insight:

Early ripening in grape (Vitis vinifera L.) is a crucial agronomic trait. The fruits of the grape line ‘Summer Black’ (SBBM), which contains a bud mutation, can be harvested approximately one week earlier than the ‘Summer Black’ (SBC)control. To investigate the molecular mechanism of the bud mutation related to early ripening, we detected genome-wide genetic variations based on re-sequencing. In total, 3,692,777 single nucleotide polymorphisms (SNPs) and 81,223 structure variations (SVs) in the SBC genome and 3,823,464 SNPs and 85,801 SVs in the SBBM genome were detected compared with the reference grape sequence. Of these, 635 SBC-specific genes and 665 SBBM-specific genes were screened. Ripening and colour-associated unigenes with non-synonymous mutations (NS), SVs or frame-shift mutations (F) were analysed. The results showed that 90 unigenes in SBC, 76 unigenes in SBBM and 13 genes that mapped to large fragment indels were filtered. The expression patterns of eight genes were confirmed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR).The re-sequencing data showed that 635 SBC-specific genes and 665 SBBM-specific genes associated with early ripening were screened. Among these, NCED6 expression appears to be related to NCED1 and is involved in ABA biosynthesis in grape, which might play a role in the onset of anthocyanin accumulation. The SEP and ERF genes probably play roles in ethylene response.

more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Frontiers | Epigenetic Control of Cell Division and Cell Differentiation in the Root Apex | Plant Evolution and Development

Frontiers | Epigenetic Control of Cell Division and Cell Differentiation in the Root Apex | Plant Evolution and Development | Plant Gene Seeker -PGS | Scoop.it
Andres Zurita's insight:

Epigenetics is defined as heritable changes in gene expression and genome integrity that are accompanied by no alteration in DNA sequence. Throughout plant life cycle, many processes, including genome imprinting, stress responses, and cellular differentiation, are known to be determined by epigenetic regulation. The root apex is also considered to be under the control of epigenetic regulation for optimal growth under variable environments. Recent reports reveal that epigenetic control is especially important in the stem cell niche and the meristematic zone where both cell production and cell specification occur. DNA methylation, histone methylation, and histone acetylation are well-known epigenetic modifications, and each epigenetic modification has distinct roles in roots. Here, we review the updated findings that demonstrate the significance of epigenetic regulation in root apex of Arabidopsis.

more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

The WUSCHEL Related Homeobox Protein WOX7 Regulates the Sugar Response of Lateral Root Development in Arabidopsis thaliana: Molecular Plant

Andres Zurita's insight:

Sugars promote lateral root formation at low levels but become inhibitory at high C/N or C/P ratios. How sugars suppress lateral root formation is unclear, however. Here we report that WOX7, a member of the WUSCHEL related homeobox (WOX) family transcription factors, inhibits lateral root development in a sugar-dependent manner. The number of lateral root primordia increased in wox7 mutants but decreased in plants over-expressing WOX7. Plants expressing the WOX7-VP16 fusion protein produced even more lateral roots than wox7, suggesting that WOX7 acts as a transcriptional repressor in lateral root development. WOX7 is expressed at all stages of lateral root development, but it is primarily involved in lateral root initiation. Consistent with this, the wox7 mutant had a higher mitotic activity only at early stages of lateral root development. Further studies suggest that WOX7 regulates lateral root development through direct repression of cell cycle genes, particularly CYCD6;1. WOX7 expression was enhanced by sugar, reduced by auxin, but did not respond to salt and mannitol. In the wox7 mutant, the effect of sugar on lateral root formation was mitigated. These results together suggest that WOX7 plays an important role in coupling the lateral root development program and sugar status in plants.

more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Bt Toxin Cry1Ie Causes No Negative Effects on Survival, Pollen Consumption, or Olfactory Learning in Worker Honey Bees (Hymenoptera: Apidae)

Bt Toxin Cry1Ie Causes No Negative Effects on Survival, Pollen Consumption, or Olfactory Learning in Worker Honey Bees (Hymenoptera: Apidae) | Plant Gene Seeker -PGS | Scoop.it
The honey bee (Apis mellifera L.) is a key nontarget insect in environmental risk assessments of insect-resistant genetically modified crops. In controlled laboratory conditions, we evaluated the potential effects of Cry1Ie toxin on survival, pollen consumption, and olfactory learning of young adult honey bees. We exposed worker bees to syrup containing 20, 200, or 20,000 ng/ml Cry1Ie toxin, and also exposed some bees to 48 ng/ml imidacloprid as a positive control for exposure to a sublethal concentration of a toxic product. Results suggested that Cry1Ie toxin carries no risk to survival, pollen consumption, or learning capabilities of young adult honey bees. However, during oral exposure to the imidacloprid treatments, honey bee learning behavior was affected and bees consumed significantly less pollen than the control and Cry1Ie groups.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Nanotechnology: A New Opportunity in Plant Sciences

Nanotechnology: A New Opportunity in Plant Sciences | Plant Gene Seeker -PGS | Scoop.it
The agronomic application of nanotechnology in plants (phytonanotechnology) has the potential to alter conventional plant production systems, allowing for the controlled release of agrochemicals (e.g., fertilizers, pesticides, and herbicides) and target-specific delivery of biomolecules (e.g., nucleotides, proteins, and activators). An improved understanding of the interactions between nanoparticles (NPs) and plant responses, including their uptake, localization, and activity, could revolutionize crop production through increased disease resistance, nutrient utilization, and crop yield. Herewith, we review potential applications of phytonanotechnology and the key processes involved in the delivery of NPs to plants. To ensure both the safe use and social acceptance of phytonanotechnology, the adverse effects, including the risks associated with the transfer of NPs through the food chain, are discussed.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Rootstocks: Diversity, Domestication, and Impacts on Shoot Phenotypes: Trends in Plant Science

Rootstocks: Diversity, Domestication, and Impacts on Shoot Phenotypes: Trends in Plant Science | Plant Gene Seeker -PGS | Scoop.it
Grafting is an ancient agricultural practice that joins the root system (rootstock) of one plant to the shoot (scion) of another. It is most commonly employed in woody perennial crops to indirectly manipulate scion phenotype. While recent research has focused on scions, here we investigate rootstocks, the lesser-known half of the perennial crop equation. We review natural grafting, grafting in agriculture, rootstock diversity and domestication, and developing areas of rootstock research, including molecular interactions and rootstock microbiomes. With growing interest in perennial crops as valuable components of sustainable agriculture, rootstocks provide one mechanism by which to improve and expand woody perennial cultivation in a range of environmental conditions.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

ABA-mediated responses to water deficit separate grapevine genotypes by their genetic background

ABA-mediated responses to water deficit separate grapevine genotypes by their genetic background | Plant Gene Seeker -PGS | Scoop.it
Abstract 
Background: ABA-mediated processes are involved in plant responses to water deficit, especially the control of stomatal opening. However in grapevine it is not known if these processes participate in the phenotypic variation in drought adaptation existing between genotypes. To elucidate this question, the response to short-term water-deficit was analysed in roots and shoots of nine Vitis genotypes differing in their drought adaptation in the field. The transcript abundance of 12 genes involved in ABA biosynthesis, catabolism, and signalling were monitored, together with physiological and metabolic parameters related to ABA and its role in controlling plant transpiration. 

Results: Although transpiration and ABA responses were well-conserved among the genotypes, multifactorial analyses separated Vitis vinifera varieties and V. berlandieri x V. rupestris hybrids (all considered drought tolerant) from the other genotypes studied. Generally, V. vinifera varieties, followed by V. berlandieri x V. rupestris hybrids, displayed more pronounced responses to water-deficit in comparison to the other genotypes. However, changes in transcript abundance in roots were more pronounced for Vitis hybrids than V. vinifera genotypes. Changes in the expression of the cornerstone ABA biosynthetic gene VviNCED1, and the ABA transcriptional regulator VviABF1, were associated with the response of V. vinifera genotypes, while changes in VviNCED2 abundance were associated with the response of other Vitis genotypes. In contrast, the ABA RCAR receptors were not identified as key components of the genotypic variability of water-deficit responses. Interestingly, the expression of VviSnRK2.6 (an AtOST1 ortholog) was constitutively lower in roots and leaves of V. vinifera genotypes and higher in roots of V. berlandieri x V. rupestris hybrids. 

Conclusions: This study highlights that Vitis genotypes exhibiting different levels of drought adaptation differ in key steps involved in ABA metabolism and signalling; both under well-watered conditions and in response to water-deficit. In addition, it supports that adaptation may be related to various mechanisms related or not to ABA responses.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

BMC Plant Biology

BMC Plant Biology | Plant Gene Seeker -PGS | Scoop.it
Background
Being sessile organisms, plants are often exposed to a wide array of abiotic and biotic stresses. Abiotic stress conditions include drought, heat, cold and salinity, whereas biotic stress arises mainly from bacteria, fungi, viruses, nematodes and insects. To adapt to such adverse situations, plants have evolved well-developed mechanisms that help to perceive the stress signal and enable optimal growth response. Phytohormones play critical roles in helping the plants to adapt to adverse environmental conditions. The elaborate hormone signaling networks and their ability to crosstalk make them ideal candidates for mediating defense responses.

Results
Recent research findings have helped to clarify the elaborate signaling networks and the sophisticated crosstalk occurring among the different hormone signaling pathways. In this review, we summarize the roles of the major plant hormones in regulating abiotic and biotic stress responses with special focus on the significance of crosstalk between different hormones in generating a sophisticated and efficient stress response. We divided the discussion into the roles of ABA, salicylic acid, jasmonates and ethylene separately at the start of the review. Subsequently, we have discussed the crosstalk among them, followed by crosstalk with growth promoting hormones (gibberellins, auxins and cytokinins). These have been illustrated with examples drawn from selected abiotic and biotic stress responses. The discussion on seed dormancy and germination serves to illustrate the fine balance that can be enforced by the two key hormones ABA and GA in regulating plant responses to environmental signals.

Conclusions
The intricate web of crosstalk among the often redundant multitudes of signaling intermediates is just beginning to be understood. Future research employing genome-scale systems biology approaches to solve problems of such magnitude will undoubtedly lead to a better understanding of plant development. Therefore, discovering additional crosstalk mechanisms among various hormones in coordinating growth under stress will be an important theme in the field of abiotic stress research. Such efforts will help to reveal important points of genetic control that can be useful to engineer stress tolerant crops.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Lipid signalling in plant responses to abiotic stress - Hou - 2016 - Plant, Cell & Environment - Wiley Online Library

Lipid signalling in plant responses to abiotic stress - Hou - 2016 - Plant, Cell & Environment - Wiley Online Library | Plant Gene Seeker -PGS | Scoop.it
Lipids are one of the major components of biological membranes including the plasma membrane, which is the interface between the cell and the environment. It has become clear that membrane lipids also serve as substrates for the generation of numerous signalling lipids such as phosphatidic acid, phosphoinositides, sphingolipids, lysophospholipids, oxylipins, N-acylethanolamines, free fatty acids and others. The enzymatic production and metabolism of these signalling molecules are tightly regulated and can rapidly be activated upon abiotic stress signals. Abiotic stress like water deficit and temperature stress triggers lipid-dependent signalling cascades, which control the expression of gene clusters and activate plant adaptation processes. Signalling lipids are able to recruit protein targets transiently to the membrane and thus affect conformation and activity of intracellular proteins and metabolites. In plants, knowledge is still scarce of lipid signalling targets and their physiological consequences. This review focuses on the generation of signalling lipids and their involvement in response to abiotic stress. We describe lipid-binding proteins in the context of changing environmental conditions and compare different approaches to determine lipid–protein interactions, crucial for deciphering the signalling cascades.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Seedling root responses to soil moisture and the identification of a belowground trait spectrum across three growth forms - Larson - 2016 - New Phytologist

Seedling root responses to soil moisture and the identification of a belowground trait spectrum across three growth forms - Larson - 2016 - New Phytologist | Plant Gene Seeker -PGS | Scoop.it
Empty description
Andres Zurita's insight:
Summary 

Root trait variation and plasticity could be key factors differentiating plant performance under drought. However, water manipulation and root measurements are rarely coupled empirically across growth forms to identify whether belowground strategies are generalizable across species. 
We measured seedling root traits across three moisture levels in 18 Mediterranean forbs, grasses, and woody species. 
Drought increased the root mass fraction (RMF) and decreased the relative proportion of thin roots (indicated by increased root diameters and decreased specific root length (SRL)), rates of root elongation and growth, plant nitrogen uptake, and plant growth. Although responses varied across species, plasticity was not associated with growth form. Woody species differed from forbs and grasses in many traits, but herbaceous groups were similar. Across water treatments, trait correlations suggested a single spectrum of belowground trade-offs related to resource acquisition and plant growth. While effects of SRL and RMF on plant growth shifted with drought, root elongation rate consistently represented this spectrum. 
We demonstrate that general patterns of root morphology and plasticity are identifiable across diverse species. Root trait measurements should enhance our understanding of belowground strategy and performance across growth forms, but it will be critical to incorporate plasticity and additional aspects of root function into these efforts.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Re-induction of the cell cycle in the Arabidopsis post-embryonic root meristem is ABA-insensitive, GA-dependent and repressed by KRP6

Re-induction of the cell cycle in the Arabidopsis post-embryonic root meristem is ABA-insensitive, GA-dependent and repressed by KRP6 | Plant Gene Seeker -PGS | Scoop.it
Seeding establishment following seed germination requires activation of the root meristem for primary root growth. We investigated the hormonal and genetic regulation of root meristem activation during Arabidopsis seed germination. In optimal conditions, radicle cell divisions occur only after the completion of germination and require de novo GA synthesis. When the completion of germination is blocked by ABA, radicle elongation and cell divisions occurred in these non-germinating seeds. Conversely under GA-limiting conditions, ABA-insensitive mutants complete germination in the absence of radicle meristem activation and growth. Radicle meristem activation and extension can therefore occur independently of completion of the developmental transition of germination. The cell cycle regulator KRP6 partially represses GA-dependent activation of the cell cycle. Germination of krp6 mutant seeds occurs more rapidly, is slightly insensitive to ABA in dose-response assays, but also hypersensitive to the GA synthesis inhibitor PAC. These conflicting phenotypes suggest the cell cycle uncouples GA and ABA responses in germinating Arabidopsis seeds, and that KRP6 acts downstream of GA to inhibit mitotic cell cycle activation during germination.
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Control of patterns of symmetric cell division in the epidermal and cortical tissues of the Arabidopsis root

Control of patterns of symmetric cell division in the epidermal and cortical tissues of the Arabidopsis root | Plant Gene Seeker -PGS | Scoop.it
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

Mobile small RNAs regulate genome-wide DNA methylation

Mobile small RNAs regulate genome-wide DNA methylation | Plant Gene Seeker -PGS | Scoop.it
Andres Zurita's insight:

Small RNAs (sRNAs) of 24 nt are associated with transcriptional gene silencing by targeting DNA methylation to complementary sequences. We demonstrated previously that sRNAs move from shoot to root, where they regulate DNA methylation of three endogenous transposable elements (TEs). However, the full extent of root DNA methylation dependent on mobile sRNAs was unknown. We demonstrate that DNA methylation at thousands of sites depends upon mobile sRNAs. These sites are associated with TE superfamilies found in gene-rich regions of the genome, which lose methylation selectively in an sRNA-deficient mutant. If the TEs were able to reactivate, they could cause genome instability and altered gene expression patterns, with negative effects on the plant. Consequently, mobile sRNAs may defend against these TEs.

more...
No comment yet.
Rescooped by Andres Zurita from Plant Sciences
Scoop.it!

Historical nectar assessment reveals the fall and rise of floral resources in Britain : Nature : Nature Publishing Group

Historical nectar assessment reveals the fall and rise of floral resources in Britain : Nature : Nature Publishing Group | Plant Gene Seeker -PGS | Scoop.it
There is considerable concern over declines in insect pollinator communities and potential impacts on the pollination of crops and wildflowers. Among the multiple pressures facing pollinators, decreasing floral resources due to habitat loss and degradation has been suggested as a key contributing factor. However, a lack of quantitative data has hampered testing for historical changes in floral resources. Here we show that overall floral rewards can be estimated at a national scale by combining vegetation surveys and direct nectar measurements. We find evidence for substantial losses in nectar resources in England and Wales between the 1930s and 1970s; however, total nectar provision in Great Britain as a whole had stabilized by 1978, and increased from 1998 to 2007. These findings concur with trends in pollinator diversity, which declined in the mid-twentieth century but stabilized more recently. The diversity of nectar sources declined from 1978 to 1990 and thereafter in some habitats, with four plant species accounting for over 50% of national nectar provision in 2007. Calcareous grassland, broadleaved woodland and neutral grassland are the habitats that produce the greatest amount of nectar per unit area from the most diverse sources, whereas arable land is the poorest with respect to amount of nectar per unit area and diversity of nectar sources. Although agri-environment schemes add resources to arable landscapes, their national contribution is low. Owing to their large area, improved grasslands could add substantially to national nectar provision if they were managed to increase floral resource provision. This national-scale assessment of floral resource provision affords new insights into the links between plant and pollinator declines, and offers considerable opportunities for conservation.

Via Saclay Plant Sciences
more...
No comment yet.
Scooped by Andres Zurita
Scoop.it!

The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea : Nature

The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea : Nature | Plant Gene Seeker -PGS | Scoop.it
Andres Zurita's insight:

Seagrasses colonized the sea1 on at least three independent occasions to form the basis of one of the most productive and widespread coastal ecosystems on the planet2. Here we report the genome of Zostera marina (L.), the first, to our knowledge, marine angiosperm to be fully sequenced. This reveals unique insights into the genomic losses and gains involved in achieving the structural and physiological adaptations required for its marine lifestyle, arguably the most severe habitat shift ever accomplished by flowering plants. Key angiosperm innovations that were lost include the entire repertoire of stomatal genes3, genes involved in the synthesis of terpenoids and ethylene signalling, and genes for ultraviolet protection and phytochromes for far-red sensing. Seagrasses have also regained functions enabling them to adjust to full salinity. Their cell walls contain all of the polysaccharides typical of land plants, but also contain polyanionic, low-methylated pectins and sulfated galactans, a feature shared with the cell walls of all macroalgae4 and that is important for ion homoeostasis, nutrient uptake and O2/CO2 exchange through leaf epidermal cells. The Z. marina genome resource will markedly advance a wide range of functional ecological studies from adaptation of marine ecosystems under climate warming5, 6, to unravelling the mechanisms of osmoregulation under high salinities that may further inform our understanding of the evolution of salt tolerance in crop plants7.

more...
No comment yet.