A wheat stress induced WRKY transcription factor TaWRKY32 confers drought stress tolerance in Oryza sativa
Essam Darwish1,2, Shoaib Ur Rehman2,3, Xinguo Mao2*, Ruilian Jing2
1Plant Physiology Section, Agricultural Botany Department, Faculty of Agriculture, Cairo University, 12613 El Gamma Street, Giza, Egypt
2National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
3Institute of Plant Breeding and Biotechnology, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan
Abstract
WRKY transcription factors group play a significant role in stress signalling pathway. In this study, a WRKY member of bread wheat, TaWRKY, was cloned and its function in response to water stress conditions was studied. Expression analysis revealed that TaWRKY32 mainly expressed when plants were subjected to PEG, NaCl, and cold and probably participate in ABA dependent signalling pathways. This study was done to elucidate the role in transgenic breeding, TaWRK32 was transferred to rice plants under CaMV-35S promoter. Overexpression of TaWRK32 lead to enhanced fresh shoot and root weight at seedling stage when compared to wild type (WT). Moreover, transgenic rice lines under water stress, showed greater recovery rate when compared to WT. Higher values of cell membrane stability and lower Chl a/b ratio of transgenic rice lines under water stress conditions markedly indicated the importance of TaWRKY32 under water stress conditions. These results suggested that TaWRK32 has multifunctional and might be an instrumental tool in breeding for transgenic plants for improved water stress tolerance in wheat.
