On a role

Flowering is a hot topic in Plant Biology and important progress has been made in Arabidopsis thaliana toward unraveling the genetic networks involved. The increasing complexity and the explosion of literature however require development of new tools for information management and update. We therefore created an evolutive and interactive database of flowering time genes, named FLOR-ID (Flowering-Interactive Database), which is freely accessible at http://www.flor-id.org. The hand-curated database contains information on 306 genes and links to 1595 publications gathering the work of >4500 authors. Gene/protein functions and interactions within the flowering pathways were inferred from the analysis of related publications, included in the database and translated into interactive manually drawn snapshots.

FLOR-ID: an interactive database of flowering-time gene networks in Arabidopsis thaliana

In nature, plants often encounter chronic or recurring stressful conditions. Recent results indicate that plants can remember a past exposure to stress to be better prepared for a future stress incident. However, the molecular basis of this is poorly understood. Here, we report the involvement of chromatin modifications in the maintenance of acquired thermotolerance (heat stress [HS] memory). HS memory is associated with the accumulation of histone H3 lysine 4 di‐ and trimethylation at memory‐related loci. This accumulation outlasts their transcriptional activity and marks them as recently transcriptionally active. High accumulation of H3K4 methylation is associated with hyper‐induction of gene expression upon a recurring HS. This transcriptional memory and the sustained accumulation of H3K4 methylation depend on HSFA2, a transcription factor that is required for HS memory, but not initial heat responses. Interestingly, HSFA2 associates with memory‐related loci transiently during the early stages following HS. In summary, we show that transcriptional memory after HS is associated with sustained H3K4 hyper‐methylation and depends on a hit‐and‐run transcription factor, thus providing a molecular framework for HS memory.

/pdf/a-hit-and-run-heat-shock-factor-governs-sustained-histone-3ow8s8lh9d.pdf

A hit-and-run heat shock factor governs sustained histone methylation and transcriptional stress memory.

Microbially Mediated Plant Salt Tolerance and Microbiome-based Solutions for Saline Agriculture.

Environmental pollution, global warming and climate change exacerbate the impact of biotic and abiotic stresses on plant growth and yield. Plants have evolved sophisticated defence network, also called innate immune system, in response to ever- changing environmental conditions. Significant progress has been made in identifying the key stress-inducible genes associated with defence response to single stressors. However, relatively little information is available on the signaling crosstalk in response to combined biotic/abiotic stresses. Recent evidence highlights the complex nature of interactions between biotic and abiotic stress responses, significant aberrant signaling crosstalk in response to combined stresses and a degree of overlap, but unique response to each environmental stimulus. Further, the results of simultaneous combined biotic and abiotic stress studies indicate that abiotic stresses particularly heat and drought enhance plant susceptibility to plant pathogens. It is noteworthy that global climate change is predicted to have a negative impact on biotic stress resistance in plants. Therefore, it is vital to conduct plant transcriptome analysis in response to combined stresses to identify general or multiple stress- and pathogen-specific genes that confer multiple stress tolerance in plants under climate change. Here, we discuss the recent advances in our understanding of the molecular mechanisms of crosstalk in response to biotic and abiotic stresses. Pinpointing both, common and specific components of the signaling crosstalk in plants, allows identification of new targets and development of novel methods to combat biotic and abiotic stresses under global climate change.

/pdf/plant-immune-system-crosstalk-between-responses-to-biotic-38ub0qtrzp.pdf

Plant Immune System: Crosstalk Between Responses to Biotic and Abiotic Stresses the Missing Link in Understanding Plant Defence.

Plants have evolved sophisticated genetic and epigenetic regulatory systems to respond quickly to unfavorable environmental conditions such as heat, cold, drought, and pathogen infections. In particular, heat greatly affects plant growth and development, immunity and circadian rhythm, and poses a serious threat to the global food supply. According to temperatures exposing, heat can be usually classified as warm ambient temperature (about 22-27℃), high temperature (27-30℃) and extremely high temperature (37-42℃, also known as heat stress) for the model plant Arabidopsis thaliana. The genetic mechanisms of plant responses to heat have been well studied, mainly focusing on elevated ambient temperature-mediated morphological acclimation and acceleration of flowering, modulation of plant immunity and circadian clock by high temperatures, and thermotolerance to heat stress. Recently, great progress has been achieved on epigenetic regulation of heat responses, including DNA methylation, histone modifications, histone variants, ATP-dependent chromatin remodeling, histone chaperones, small RNAs, long non-coding RNAs and other undefined epigenetic mechanisms. These epigenetic modifications regulate the expression of heat-responsive genes and function to prevent heat-related damage. This review focuses on recent progresses regarding the genetic and epigenetic control of heat responses in plants, and pays more attention to the role of the major epigenetic mechanisms in plant heat responses. Further research perspectives are also discussed.

/pdf/genetic-and-epigenetic-control-of-plant-heat-responses-25nu3qfggj.pdf

Lili Feng

Papers

Genetic and epigenetic control of plant heat responses