Heat Stress Responsive Genes in Wheat
Climate change and global warming has introduced new challenges for modern agriculture. Wheat is a staple food worldwide and it is crucial to gain further understanding of how heat stress is effecting wheat production and wheat biology. High temperature during the reproductive stage decreases yield by 15%. Heat stress causes drying of fluid on stigmatic surface, reduces enzymatic activity critical for photosynthesis and starch biosynthesis pathways, and over expression of heat shock proteins. Next Generation Sequencing has been utilized for transcriptome study and has provided useful data on the regulatory pathway networks operating in plants under different conditions. At the Indian Agriculture Research Institute in New Delhi, India, a study was performed in which the whole transcriptome of wheat in the flowering stage at control temperature and heat stress temperature. Sequencing was done using Illumina HiSeq and Roche GS-FLX 454 platforms.
When comparing transcriptomes of wheat plants in heat stress temperature (42°C for 2 hours) to controlled temperature (22°C), 716 transcripts were up-regulated and 809 were down regulated. Most of the up-regulated transcripts were associated with metabolic pathways, biosynthesis of secondary metabolites, and oxidative phosphorylation. Down regulated transcripts were associated with starch and sucrose metabolism. De Novo transcriptome analysis revealed a significant fold change in the expression of 1525 genes. The high stress temperature treatment down regulated genes included the synthesis of cell wall resulting in disintegration of cell wall.
High throughput Next Generation Sequencing has contributed significantly in the identification of genes associated with climate stress. Various crops have also been subjected to Next Generation Sequencing in order to identify these genes. These crops include chickpeas, rice, sorghum, soybean, and parsley.