Transcriptomics of Heat Stress in Plants

Abstract

High-temperature stress is a major abiotic stress that affects various biological processes of plants such as biochemical and physiological response, growth, development, and yield. High-temperature stress has critical effects at cellular and molecular levels also. The increased concentration of regulatory proteins such as heat shock transcription factors (Hsfs) is a major molecular response that occurs during heat stress. These regulatory proteins in turn regulate the expression of heat shock protein (HSP) genes that act as critical players during stress to maintain cell homeostasis. Besides HSPs, the other metabolic and regulatory genes, signaling compounds, compatible osmolytes, and antioxidants too play an important role during heat stress in plants. Apart from the protein-coding genes, recent studies have shown that noncoding microRNAs (miRNAs) also play a key role during heat stress by modulating the gene expression at the transcription and post-transcriptional level. The transcriptome approaches are important to understand the molecular and cellular changes occurring in response to heat stress. The approaches rely mostly by adopting the traditional methods like Northern blot/RNA blot and reverse transcription PCR (RT-PCR), where the expression of the genes can be studied in different tissues and cells, whereas the extent of their expression can be achieved by quantitative PCR or real time PCR. Further, the genome-wide expression profiling tools such as microarray analysis, next-generation sequencing, and RNA sequencing offer a great potential in this direction. This chapter primarily provides the current understanding on the role of regulatory genes (transcription factors), HSP genes, metabolic genes, signaling compounds, osmolytes, reactive oxygen species, and miRNAs as well as other small RNAs of plants under high temperature. In addition, it gives a brief account of various transcriptome approaches to study the expression profiling of genes during heat stress.