Genome-Wide Identification and Functional Prediction of the GRAS Transcription Factor Family in Rice Under Abiotic Stress Conditions

GRAS transcription factors play a crucial role in plant response to abiotic stresses. In this study, 61 members of the rice GRAS family, categorized into nine subfamilies, were identified by searching the latest genome sequence of rice. The OsGRAS genes that may respond to abiotic stresses were predicted by analyzing the cis-acting elements of the promoters of the genes and the structural features of the proteins. The results showed that the known OsGRAS drought-tolerant genes and OsGRAS salt-tolerant genes have a special structure in their protein structures, and nine genes that may be related to drought tolerance and six genes that may be related to salt tolerance were predicted in this study based on these special structures. The results of tissue expression profiling showed that OsGRAS family genes were expressed in different degrees during plant growth and development, and the expression of DELLA, PAT1, and HAM subfamily members was generally high. Finally, the analysis of the expression levels of 16 randomly selected OsGRAS genes under drought and salt stress conditions showed significant up-regulation of OsGRAS14 and OsGRAS21 under both stress treatments, and OsGRAS52 was significantly down-regulated under drought stress and up-regulated under salt stress. The present study provides important clues for exploring the molecular basis of the mechanism of rice response to abiotic stress, and also provides new ideas for the improvement of rice germplasm resources.