Genome-Wide Identification of GRAS Transcription Factors and Their Potential Roles in Growth and Development of Rose (Rosa chinensis)

Plant-specific GRAS transcription factors (TFs) are reported to play an essential role in regulating several biological processes, such as plant growth and development, phytochrome signal, arbuscular mycorrhiza symbiosis, stress responses. However, rose GRAS genes are still unexplored. In this study, 59 rose GRAS genes (RcGRAS) were identified and were grouped into 17 subfamilies. Gene structure analyses showed that most of the RcGRAS genes were intronless and were relatively conserved. Gene expression analysis in various tissues (leaf, stem and flower bud) identified the tissue-specific expression of GRAS genes. For instance, RcGRAS30 (SCL3) and RcGRAS9 (HAM) got > 20 fold and > 5 folds upregulated in stem as comparison to leaf, and suggested their possible involvement in different growth and development processes. Further, significant difference in expression of GRAS genes in response to exogenous gibberellin (GA) and drought stress alluded the potential functions of these genes in hormone and stress responses. In summary, a comprehensive exploration of the rose GRAS gene family was performed and also their possible role in growth, development, stress and hormonal response were depicted. These basic insights can be utilized for further functional characterization-based studies on GRAS genes.