The heat responsive wheat TaRAD23 rescues developmental and thermotolerant defects of the rad23b mutant in Arabidopsis thaliana.

High temperature severely damage the growth and development of crops with climate change. To effectively screen heat responsive proteins in wheat (Triticum aestivum L.), the isobaric tandem mass tag (TMT)-labeled quantitative proteomic analysis and quantitative real-time PCR (qRT-PCR) were performed. Here, we found that a wheat RADIATION SENSITIVE 23 protein, TaRAD23, was up-regulated at both protein and RNA levels by exposing to heat stress. Sequence homology analysis indicated that the TaRAD23 is a conserved protein, which is closely related to the Arabidopsis thaliana proteins AtRAD23B and AtRAD23A. Genetic knockout of AtRAD23B, but not AtRAD23A, shows multiple developmental defects, as well as sensitivity to heat stress. Meanwhile, we observed that constitutive overexpression of TaRAD23 in rad23b fully rescued developmental and thermotolerant defects of the mutant. Furthermore, qRT-PCR analysis of heat responsive genes in rad23b and its complementary lines suggested that suppression of the heat shock transcription factor AtHSFA2 and heat responsive genes (HSP70, HSP90, HSP17.6 and HSA32) may be the cause of the weaker thermotolerance in rad23b. Taken together, the data suggest that the heat responsive TaRAD23 is a functionally highly conserved protein that plays an important role in development, as well as the regulation in heat stress response network.