Search

Heat stress greatly affects plant growth/development and influences the output of crops. With the increased occurrence of extreme high temperature, the negative influence on cereal products from heat stress becomes severer and severer. It is urgent to reveal the molecular mechanism in response to heat stress in plants. In this research, we used RNA-seq technology to identify differentially expressed genes (DEGs) in leaves of seedlings, leaves and inflorescences at heading stage of Brachypodium distachyon, one model plant of grasses. Results showed many genes in responding to heat stress. Of them, the expression level of 656 DEGs were altered in three groups of samples treated with high temperature. Gene ontology (GO) analysis showed that the highly enriched DEGs were responsible for heat stress and protein folding. According to KEGG pathway analysis, the DEGs were related mainly to photosynthesis-antenna proteins, the endoplasmic reticulum, and the spliceosome. Additionally, the expression level of 454 transcription factors belonging to 49 gene families was altered, as well as 1,973 splicing events occurred after treatment with high temperature. This research lays a foundation for characterizing the molecular mechanism of heat stress response and identifying key genes for those responses in plants. These findings also clearly show that heat stress regulates the expression of genes not only at transcriptional level, but also at post-transcriptional level. [ABSTRACT FROM AUTHOR]

Higher plants are subjected to a large number of environmental (biotic and abiotic) stresses. High temperature stress lead to a series of morphological, physiological, biochemical and molecular changes that adversely affect plant growth and productivity. Plants synthesize heat-shock proteins (HSPs) in response to high temperature stress. The major HSPs synthesized by eukaryotes, including plants, belong to those evolutionary conserved classes: HSP110, HSP90, HSP70, HSP60, small HSPs (smHSPs, ~17 to 30 kDa) and ubiquitin (HSP 8.5 kDa). The synthesis and accumulation of HSPs is accompanied by a decrease in normal protein synthesis. The appearance of plant heat-shock proteins is strongly correlated with the development of a condition termed "acquired thermotolerance". Acquired thermotolerance is induced by sublethal temperatures and leads to enhanced protection of plant cells from subsequent heat-induced injury. The acquisition of thermotolerance depends not only upon the synthesis and accumulation of HSPs but also on their cellular localization. During high temperature stress, many enzymes and structural proteins undergo deleterious structural and functional changes. HSPs/molecular chaperones are responsible for many normal cellular processes. In addition, HSPs/molecular chaperones function in the stabilization of proteins and membranes, and in assisting protein refolding under stress conditions. [ABSTRACT FROM AUTHOR]