Plant science
165 views | +0 today
Follow
Your new post is loading...
Your new post is loading...
Rescooped by Carlos Hidalgo from Plant Biology Teaching Resources (Higher Education)
Scoop.it!

A comprehensive analysis of root morphological changes and nitrogen allocation in maize in response to low-nitrogen stress

A comprehensive analysis of root morphological changes and nitrogen allocation in maize in response to low-nitrogen stress | Plant science | Scoop.it

The plasticity of root architecture is crucial for plants to acclimate unfavorable environments including low nitrogen (LN) stress. How maize roots coordinate the growth of axile roots and lateral roots (LRs), as well as longitudinal and radial cell behaviours in response to LN stress remains unclear. Maize plants were cultivated hydroponically under control (4 mM nitrate) and LN (40 μM) conditions. Temporal and spatial samples were taken to analyse changes in the morphology, anatomical structure, and carbon/nitrogen (C/N) ratio in the axile and lateral roots. LN stress increased axile root elongation, reduced the number of crown roots, and decreased LR density and length. LN extended cell elongation zones and increased the mature cell length in the roots. LN reduced the cell diameter and total area of vessels and increased the amount of aerenchyma, but the number of cell layers in the crown root cortex was unchanged. The C/N ratio was higher in axile roots than in LRs. Maize roots acclimate to LN by optimizing the anatomical structure and N allocation. As a result axile root elongation is favored to efficiently find available N in the soil.


Via Christophe Jacquet, Mary Williams
more...
No comment yet.
Rescooped by Carlos Hidalgo from Amazing Science
Scoop.it!

Parasitic Plant Strangleweed Injects Host With Over 9,000 RNA Transcripts

Parasitic Plant Strangleweed Injects Host With Over 9,000 RNA Transcripts | Plant science | Scoop.it

Virginia Tech professor and Fralin Life Institute affiliate Jim Westwood has made a discovery about plant-to-plant communication: enormous amounts of genetic messages in the form of mRNA transcripts are transmitted from the parasitic plant Cuscuta (known more commonly as dodder and strangleweed) to its hosts.

 

Using Illumina next generation sequencing technologies to sequence the tissues of the host and an attached parasite, the team found that the number of genes that gets passed into the host depends on the identity of the host.  The tomato plant received 347 of the strangleweed’s mRNAs, whereas the Arabidopsis received an astonishing 9514 mRNAs.  When Arabidopsis plant receives this many mRNAs, the total genetic material of tissues in contact with the strangleweed is about 45% from the parasite.

 

The new quantitative result builds on Professor Westwood’s prior discovery of RNA transfer between the parasitic plant and its host plants.  In the prior study, Westwood found that when the strangleweed uses its haustorium (piercing appendage) to penetrate the stems of its host plants, it passes on its own RNA to the host, though only tens of mRNAs were identified.  The discovery challenged our understanding that mRNAs are mainly kept within cells.

 

But now the research team has quantified the extent to which the messages are passed.  mRNA stands for “messenger RNA” and are the snippets of genetic information that are created from DNA.  Typically an mRNA molecule is “read” by a molecule machine known as a ribosome and turned into a protein which carries out particular functions in the cell.  And usually, more mRNAs means more protein.  Therefore, the conversion from DNA to mRNA is one way to amplify or control the activation of a gene.

 

It is not yet clear what are the functions of the transmitted genes but bioinformatic analysis shows that hydrolase activity, metabolism and response to stimulus gene groups were among the most represented in those that crossed the species bridge.

 

Westwood has determined that the host plant may be receiving orders of a kind from the parasitic plant, such as lowering its natural defense system so that the strangleweed can more easily attack them.

 

The findings by Westwood, Professor of weed science, plant pathology and physiology at the College of Agriculture and Life Sciences, is even more surprising when considered against prior thought that mRNA is unstable, short-lived and fragile.

 

The discoveries also opens new avenues in the research of the eradication of parasitic plants such as broomrape and witchweed, two plants that pose serious threats to legumes and other crops.  This also has intriguing implications for increasing efficiency of yields.

 

Future plans include expansion of such research to other organismal domains, such as fungi and bacteria, also exchange the mRNA.  But the meaning and the outcome of the transmitted messages remain yet unclear and work must be done to find out what the plants are saying to each other.


Via Dr. Stefan Gruenwald
more...
Rescooped by Carlos Hidalgo from Plant Stress
Scoop.it!

How do plants remember winter cold?

How do plants remember winter cold? | Plant science | Scoop.it
How do plants remember winter cold? Prof Martin Howard explains how he uses mathematical and experimental methods to answer this question.

Via Eve Emshwiller, R K Upadhyay
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Roots
Scoop.it!

NatRevMicrobiol: Microbial ecology of rhizosphere

NatRevMicrobiol: Microbial ecology of rhizosphere | Plant science | Scoop.it

Via Mary Williams, Ruben Rellan
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Gene Seeker -PGS
Scoop.it!

Jasmonate signalling: a copycat of auxin signalling? - Plant, Cell & Environment

Jasmonate signalling: a copycat of auxin signalling? - Plant, Cell & Environment | Plant science | Scoop.it

Via Andres Zurita
more...
Andres Zurita's curator insight, October 25, 2013 4:03 PM

Plant hormones regulate almost all aspects of plant growth and development. The past decade has provided breakthrough discoveries in phytohormone sensing and signal transduction, and highlighted the striking mechanistic similarities between the auxin and jasmonate (JA) signalling pathways. Perception of auxin and JA involves the formation of co-receptor complexes in which hormone-specific E3-ubiquitin ligases of the SKP1-Cullin-F-box protein (SCF) type interact with specific repressor proteins. Across the plant kingdom, the Aux/IAA and the JASMONATE-ZIM DOMAIN (JAZ) proteins correspond to the auxin- and JA-specific repressors, respectively. In the absence of the hormones, these repressors form a complex with transcription factors (TFs) specific for both pathways. They also recruit several proteins, among which the general co-repressor TOPLESS, and thereby prevent the TFs from activating gene expression. The hormone-mediated interaction between the SCF and the repressors targets the latter for 26S proteasome-mediated degradation, which, in turn, releases the TFs to allow modulating hormone-dependent gene expression. In this review, we describe the similarities and differences in the auxin and JA signalling cascades with respect to the protein families and the protein domains involved in the formation of the pathway-specific complexes.

Rescooped by Carlos Hidalgo from Plant Stress
Scoop.it!

New insight into photosynthesis: Carotenoids can capture blue/green light and pass energy on to chlorophylls

New insight into photosynthesis: Carotenoids can capture blue/green light and pass energy on to chlorophylls | Plant science | Scoop.it
Pigments found in plants and purple bacteria employed to provide protection from sun damage do more than just that. Researchers have found that they also help to harvest light energy during photosynthesis.

Via R K Upadhyay
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Stress
Scoop.it!

Science: Nonlegumes Respond to Rhizobial Nod Factors by Suppressing the Innate Immune Response

Science: Nonlegumes Respond to Rhizobial Nod Factors by Suppressing the Innate Immune Response | Plant science | Scoop.it

Several nonleguminous plants, including Arabidopsis, tomato, and corn, were able to respond to the same Nod factors that initiate the microbial symbiosis in soybean.This figure shows that the addition of Nod Factor (NF) supresses the immune response triggered by the flg22 peptide. The authors also show that, "Plants defective in the LYK3 protein failed to suppress flg22-triggered ROS production upon Nod factor addition, whereas ectopic overexpression of LYK3 enhanced Nod factor–induced suppression of ROS production".


Via Mary Williams, R K Upadhyay
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Physiology
Scoop.it!

Plant Cell (review, $): Plant Callus, Mechanisms of Induction and Repression

Plant Cell (review, $): Plant Callus, Mechanisms of Induction and Repression | Plant science | Scoop.it

Nice review about genetic and epigenetic mechanisms underlying callus formation.


Via Mary Williams, Gib Udomchalothorn
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Gene Seeker -PGS
Scoop.it!

Trends in Plant Science - Ammonium stress in Arabidopsis: signaling, genetic loci, and physiological targets


Via Andres Zurita
more...
Andres Zurita's curator insight, October 14, 2013 8:55 AM
HighlightsWe review genetic loci, signaling pathways, and physiological targets of NH4+stress in the model system Arabidopsis thaliana.Differing NH4+ stress responses between belowground and aboveground sources are dissected.New experimental approaches to the study of NH4+ toxicity are outlined.An integrated view of behavior and signaling in response to NH4+ stress is proposed.Summary

Ammonium (NH4+) toxicity is a significant ecological and agricultural issue, and an important phenomenon in cell biology. As a result of increasing soil nitrogen input and atmospheric deposition, plants have to deal with unprecedented NH4+ stress from sources below and above ground. In this review, we describe recent advances in elucidating the signaling pathways and identifying the main physiological targets and genetic loci involved in the effects of NH4+ stress in the roots and shoots of Arabidopsis thaliana. We outline new experimental approaches that are being used to study NH4+ toxicity in Arabidopsis and propose an integrated view of behavior and signaling in response to NH4+ stress in the Arabidopsis system.

Scooped by Carlos Hidalgo
Scoop.it!

Cytokinin Induces Cell Division in the Quiescent Center of the Arabidopsis Root Apical Meristem

Cytokinin Induces Cell Division in the Quiescent Center of the Arabidopsis Root Apical Meristem | Plant science | Scoop.it

SummaryBackground

In the root apical meristem, which contains the stem cells that feed into root development, the phytohormones auxin and cytokinin play opposing roles, with auxin promoting cell division and cytokinin promoting cell differentiation. Cytokinin acts in the root tip in part by modulating auxin transport through regulation of the level of the PIN auxin efflux carriers. Auxin plays a key role in the specification of the quiescent center (QC), which is essential for maintaining the stem cell fate of the surrounding cells.

Results

We demonstrate that cytokinin promotes cell division in the QC, which is generally mitotically inactive. Cytokinin downregulates the expression of several key regulatory genes in the root tip, including SCARECROW, WOX5, and the auxin influx carriers AUX1 and LAX2. The decrease in LAX2 expression in response to cytokinin requires ARR1 and ARR12, two type B ARRs that mediate the primary transcriptional response to cytokinin. ARR1 was found to bind directly to the LAX2 gene in vivo, which indicates that type B ARRs directly regulate genes that are repressed by cytokinin. Disruption of the LAX2 gene results in a phenotype similar to that observed in response to cytokinin, including increased division of the cells in the QC and decreased expression of WOX5 and the auxin response reporter DR5.

Conclusions

Cytokinin acts to regulate auxin distribution in the root apical meristem by regulating both the PINs and LAX2. This redistribution of auxin, potentially coupled with other auxin-independent effects of cytokinin, regulates the mitotic activity in the QC.

.

more...
No comment yet.
Scooped by Carlos Hidalgo
Scoop.it!

Strigolactones...more than enough to keep plant scientists occupied

For instance, strigolactones are known to promote root hair elongation, inhibit shoot branching, promote hyphae branching in Arbuscular Mycorrhiza Fungi and to stimulate the germination of parasitic plants (hence their strong ...
more...
No comment yet.
Scooped by Carlos Hidalgo
Scoop.it!

Frontiers | Endogenous auxin and jasmonic acid levels are differentially modulated by abiotic stresses in rice | Frontiers in Plant Physiology

Abiotic stresses such as drought, salinity, and adverse temperatures are major limiting factors for plant growth and reproduction.
more...
No comment yet.
Scooped by Carlos Hidalgo
Scoop.it!

Rare flower discovered in Aurora - Philippine Star

Rare flower discovered in Aurora - Philippine Star | Plant science | Scoop.it
Sun.Star
Rare flower discovered in Aurora
Philippine Star
Found only in the Philippines, R. manillana is a genus of tropical parasitic plants that do not contain chlorophyll and therefore are incapable of photosynthesis.
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Biology Teaching Resources (Higher Education)
Scoop.it!

Can Plants Grow on Mars and the Moon: A Growth Experiment on Mars and Moon Soil Simulants

Can Plants Grow on Mars and the Moon: A Growth Experiment on Mars and Moon Soil Simulants | Plant science | Scoop.it

Science fair project anyone? My first thought was, "How to you make Martian soil?" and the answer is, you can BUY growth substrates that simulate Martian / moon soils. How about that.

http://www.orbitec.com/store/simulant.html

 

The only concern I have is about the first sentence of the abstract - "WHEN humans will settle on the moon or Mars they will have to eat there". Personally, I'd rather we put our energy into keeping earth habitable, thank you!


Via Mary Williams
more...
No comment yet.
Rescooped by Carlos Hidalgo from Botany teaching & cetera
Scoop.it!

Can Plants Think?

Can Plants Think? | Plant science | Scoop.it
Plants can hear, taste and feel, as Michael Pollan writes in his latest piece for The New Yorker. But is any of that evidence of intelligence? (Can Plants Think? 'll be on Science Friday tomorrow, last segment, talking about plant intelligence.

Via Eve Emshwiller
more...
No comment yet.
Rescooped by Carlos Hidalgo from plant cell genetics
Scoop.it!

Protein Secretome of Moss Plants (Physcomitrella patens) with Emphasis on Changes Induced by a Fungal Elicitor

Protein Secretome of Moss Plants (Physcomitrella patens) with Emphasis on Changes Induced by a Fungal Elicitor | Plant science | Scoop.it

Studies on extracellular proteins (ECPs) contribute to understanding of the multifunctional nature of apoplast. Unlike vascular plants (tracheophytes), little information about ECPs is available from nonvascular plants, such as mosses (bryophytes). In this study, moss plants (Physcomitrella patens) were grown in liquid culture and treated with chitosan, a water-soluble form of chitin that occurs in cell walls of fungi and insects and elicits pathogen defense in plants. ECPs released to the culture medium were compared between chitosan-treated and nontreated control cultures using quantitative mass spectrometry (Orbitrap) and 2-DE-LC-MS/MS. Over 400 secreted proteins were detected, of which 70% were homologous to ECPs reported in tracheophyte secretomes. Bioinformatics analyses using SignalP and SecretomeP predicted classical signal peptides for secretion (37%) or leaderless secretion (27%) for most ECPs of P. patens, but secretion of the remaining proteins (36%) could not be predicted using bioinformatics. Cultures treated with chitosan contained 72 proteins not found in untreated controls, whereas 27 proteins found in controls were not detected in chitosan-treated cultures. Pathogen defense-related proteins dominated in the secretome of P. patens, as reported in tracheophytes. These results advance knowledge on protein secretomes of plants by providing a comprehensive account of ECPs of a bryophyte.


Via Jean-Pierre Zryd
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Stress
Scoop.it!

Halotropism Is a Response of Plant Roots to Avoid a Saline Environment

Halotropism Is a Response of Plant Roots to Avoid a Saline Environment | Plant science | Scoop.it

Via Mary Williams, R K Upadhyay
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Stress
Scoop.it!

How Plants Feel

How Plants Feel | Plant science | Scoop.it
A hormone called jasmonate mediates plants' responses to touch and can boost defenses against pests.

Via R K Upadhyay
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant Stress
Scoop.it!

How do plants grow toward the light? Scientists explain mechanism behind phototropism

How do plants grow toward the light? Scientists explain mechanism behind phototropism | Plant science | Scoop.it
Plants have developed a number of strategies to capture the maximum amount of sunlight through their leaves. As we know from looking at plants on a windowsill, they grow toward the sunlight to be able to generate energy by photosynthesis.

Via R K Upadhyay
more...
María Serrano's curator insight, June 24, 2014 12:30 PM
Explicación científica del fototropismo
Rescooped by Carlos Hidalgo from Plant Gene Seeker -PGS
Scoop.it!

Cytokinin Induces Cell Division in the Quiescent Center of the Arabidopsis Root Apical Meristem

Cytokinin Induces Cell Division in the Quiescent Center of the Arabidopsis Root Apical Meristem | Plant science | Scoop.it

SummaryBackground

In the root apical meristem, which contains the stem cells that feed into root development, the phytohormones auxin and cytokinin play opposing roles, with auxin promoting cell division and cytokinin promoting cell differentiation. Cytokinin acts in the root tip in part by modulating auxin transport through regulation of the level of the PIN auxin efflux carriers. Auxin plays a key role in the specification of the quiescent center (QC), which is essential for maintaining the stem cell fate of the surrounding cells.

Results

We demonstrate that cytokinin promotes cell division in the QC, which is generally mitotically inactive. Cytokinin downregulates the expression of several key regulatory genes in the root tip, including SCARECROW, WOX5, and the auxin influx carriers AUX1 and LAX2. The decrease in LAX2 expression in response to cytokinin requires ARR1 and ARR12, two type B ARRs that mediate the primary transcriptional response to cytokinin. ARR1 was found to bind directly to the LAX2 gene in vivo, which indicates that type B ARRs directly regulate genes that are repressed by cytokinin. Disruption of the LAX2 gene results in a phenotype similar to that observed in response to cytokinin, including increased division of the cells in the QC and decreased expression of WOX5 and the auxin response reporter DR5.

Conclusions

Cytokinin acts to regulate auxin distribution in the root apical meristem by regulating both the PINs and LAX2. This redistribution of auxin, potentially coupled with other auxin-independent effects of cytokinin, regulates the mitotic activity in the QC.

.


Via Andres Zurita
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plants and Microbes
Scoop.it!

Nature: Symbiosis leads to diversity (2013)

Nature: Symbiosis leads to diversity (2013) | Plant science | Scoop.it

http://www.nature.com/nature/journal/v494/n7436/full/494151c.html

 

Species interactions such as competition and predation spur on diversification — as can symbiotic relationships, a study of plant-invading insects has found.

 

Many species of a family of insects known as gall midges (Cecidomyiidae) rely on fungi to help them break down plant tissues; in return, the female gall midges deposit the fungal spores along with their eggs when they move from plant to plant. In a survey of the literature, Jeffrey Joy at Simon Fraser University in Burnaby, British Columbia, Canada, found that gall midges that are associated with fungi tend to use a wider variety of host plants (pictured) compared with those with no association. Moreover, his analysis of gall-midge lineages revealed that symbiotic insect species are more than 17 times as diverse as non-symbiotic ones.

 

Forming a relationship with plant-digesting fungi could allow for greater evolutionary diversity in other insect species by providing them with a greater number of potential hosts, Joy suggests.

 

Proc. R. Soc. B http://dx.doi.org/10.1098/rspb.2012.2820


Via Kamoun Lab @ TSL
more...
No comment yet.
Scooped by Carlos Hidalgo
Scoop.it!

A step towards increasing crop productivity

A step towards increasing crop productivity | Plant science | Scoop.it
(Phys.org) —A breakthrough in understanding the evolutionary pathways along which some crops have become significantly more productive as others may help scientists boost yields of some staple foodstuffs.
more...
No comment yet.
Rescooped by Carlos Hidalgo from Plant protection
Scoop.it!

US: New study offers hope for halting incurable citrus disease - FreshPlaza

US: New study offers hope for halting incurable citrus disease - FreshPlaza | Plant science | Scoop.it
US: New study offers hope for halting incurable citrus disease FreshPlaza Furthermore, the researchers discovered that HLB interfered with the regulation of hormones such as salicylic acid, jasmonic acid and ethylene, which are "the backbone" of...
more...
No comment yet.
Scooped by Carlos Hidalgo
Scoop.it!

The Root of the Matter: The Role of Nitric Oxide in Root Branching - Science Daily (press release)

The Root of the Matter: The Role of Nitric Oxide in Root Branching - Science Daily (press release) | Plant science | Scoop.it
The Root of the Matter: The Role of Nitric Oxide in Root Branching
Science Daily (press release)
Oct.
more...
No comment yet.