Genome-wide Identification of the GRAS Gene Family of Actinidia Arguta

GRAS transcription factors play important roles in plant growth, development, and abiotic and biotic stress responses. In this study, the genome-wide identification of the transcription factor family of Actinidia arguta was carried out including an analysis of the physical and chemical properties, phylogenetic development, gene structure, collinearity between genes, and protein interactions. A total of 88 GRAS genes were identified in the genome of Actinidia arguta with protein lengths of 103-510 aa, a molecular mass of 11,603.25-22,457.96 kDa, and isoelectric points in the hydrophilic range between 4.45 and 6.50 From these genes, 67 were located in the nucleus and 21 in the chloroplast. The identified genes were further divided into eight subfamilies: SCR, HAM, DELLA, PAT1, SHR, SCL4/7, and GIGR. Members of the same subfamily had similar gene structures and conserved motifs. Motif 5 was highly conserved in the GRAS family. On the chromosomes of LG3, LG15, LG22, LG24, LG26 and LG28, there was a large number of tandem duplications of GRAS genes, with 64 pairs of genes orthologous with Arabidopsis thaliana. The analysis of protein interactions found that there were interactive relationships between SCL28 in the DLT subfamily and SCL14 in the LISCL subfamily and between SCL13 in the PAT1 subfamily and proteins of the LAS subfamily. Interactions were also observed between the SCL30, SCL33, and HAM4 proteins in the LISCL subfamily. This study, therefore, provides a reference for mining and verification within the GRAS genes in the Actinidia arguta genome.

The GRAS gene family and its roles in seed development in litchi (Litchi chinensis Sonn)

Background The GRAS gene family plays crucial roles in multiple biological processes of plant growth, including seed development, which is related to seedless traits of litchi (Litchi chinensis Sonn.). However, it hasn’t been fully identified and analyzed in litchi, an economic fruit tree cultivated in subtropical regions. Results In this study, 48 LcGRAS proteins were identified and termed according to their chromosomal location. LcGRAS proteins can be categorized into 14 subfamilies through phylogenetic analysis. Gene structure and conserved domain analysis revealed that different subfamilies harbored various motif patterns, suggesting their functional diversity. Synteny analysis revealed that the expansion of the GRAS family in litchi may be driven by their tandem and segmental duplication. After comprehensively analysing degradome data, we found that four LcGRAS genes belong to HAM subfamily were regulated via miR171-mediated degradation. The various expression patterns of LcGRAS genes in different tissues uncovered they were involved in different biological processes. Moreover, the different temporal expression profiles of LcGRAS genes between abortive and bold seed indicated some of them were involved in maintaining the normal development of the seed. Conclusion Our study provides comprehensive analyses on GRAS family members in litchi, insight into a better understanding of the roles of GRAS in litchi development, and lays the foundation for further investigations on litchi seed development.

Characterization of the GRAS gene family reveals their contribution to the high adaptability of wheat

GRAS transcription factors play important roles in many processes of plant development as well as abiotic and biotic stress responses. However, little is known about this gene family in bread wheat (Triticum aestivum), one of the most important crops worldwide. The completion of a quality draft genome allows genome-wide detection and evolutionary analysis of the GRAS gene family in wheat. In this study, 188 TaGRAS genes were detected and divided into 12 subfamilies based on phylogenetic analyses: DELLA, DLT, HAM, LISCL, SCL3, SCL4/7, SCR, SHR, PAT1, Os19, Os4 and LAS. Tandem and segmental duplications are the main contributors to the expansion of TaGRAS, which may contribute to the adaptation of wheat to various environmental conditions. A high rate of homoeolog retention during hexaploidization was detected, suggesting the nonredundancy and biological importance of TaGRAS homoeologs. Systematic analyses of TaGRAS indicated the conserved expression pattern and function of the same subfamily during evolution. In addition, we detected five genes belonging to the LISCL subfamily induced by both biotic and abiotic stresses and they may be potential targets for further research through gene editing. Using degradome and ChIP-seq data, we identified the targets of miR171 and histone modifications and further analyzed the contribution of epigenetic modification to the subfunctionalization of TaGRAS. This study laid a foundation for further functional elucidation of TaGRAS genes.