MicroRNA-guided regulation of heat stress response in wheat at flag leaf and 10 days after anthesis

Sequencing of 8 small RNA libraries produced 14.3M reads and a comparative analysis of miRNAs in flag leaf as well as developing seeds of RAJ3765 (Heat Tolerant) and HUW510 (Heat Sensitive) wheat genotypes under heat stress and normal conditions using small RNA were carried out. A total of 8 libraries were prepared and sequenced yielding 84 conserved miRNAs and 93 novel miRNAs belonging to 35 miRNA families. Comparison between heat-treated and control groups revealed that 32 conserved and 15 novel miRNAs were differentially expressed in the flag leaves of the HT genotype. Similarly, 40 conserved and 18 novel miRNAs showed differential expression in the flag leaves of the HS (heat sensitive) genotype. Also, 37 conserved and 12 novel miRNAs showed differential expression in the developing seeds of HT and HS genotypes. The validation results of randomly selected 10 up- or downregulated miRNAs through qPCR were consistent with the expression pattern revealed by small RNA sequencing.