Transcriptome based identification and validation of heat stress transcription factors in wheat progenitor species Aegilops speltoides

Abstract

\n Wheat, one of the major cereal crops worldwide, get adversely affected by rising global temperature. We have identified the diploid B genome progenitor of wheat, Aegilops speltoides (SS), as a potential donor for heat stress tolerance. Therefore, the objective of the present work was to study the total transcriptome profile of Ae. speltoides accession pau3809 and compare with that of tetraploid and hexaploid wheat cultivars PDW274 and PBW725, respectively. The comparative transcriptome was utilized to identify and validate heat stress transcription factors (HSFs), the key genes involved in imparting heat stress tolerance. Transcriptome analysis led to the identification of a total of 74K, 68K, and 76K genes in AS3809, PDW274, and PBW725, respectively. There was a high uniformity of GO profiles under the biological, molecular, and cellular functions across the three wheat transcriptomes, suggesting the conservation of gene function. Twelve HSFs with the highest FPKM value in the Ae. speltoides transcriptome data were selected and six of these HSFs namely HSFA3, HSFA5, HSFA9, HSFB2a, HSFC1b, and HSFB2b were validated with qRT PCR. These six HSFs were identified as an important component of thermotolerance in Ae. speltoides as evident from their comparative higher expression under heat stress.