Genome-wide Identification,Evolutionary And Expression Analysis Of The RNA-binding Glycine-rich Protein In Diploid Cotton Family In Diploid Cotton

The RB-GRP gene family belongs to the fourth subfamily of the GRP superfamily. It is widely found in all kinds of plants, and it plays an important role in growth and development of plants, as well as responses for abiotic stresses. Cotton is important economic crop. The fiber is the natural raw and material of the textile industry. But in the present study, the function of the RB-GRP genes in diploid cotton have been unknown.This study identified the gene family at the genomic level and analyzed its evolutionary history, which laid the foundation for further study on the function of the proteins. And proving how the proteins conferred stress tolerance and mechanism to the plant in the process of growth and development, which could provided a solid theoretical foundation for improving the cotton fiber quality and breeding good cotton varieties.In this study, genome-wide identification, evolutionary and expression analysis of RB-GRP genes were executed through bioinformatics and molecular biology strategies in diploid cotton. The main results are as follows:1. In this study, 37 and 32 RB-GRP genes from G. arboreum and G. raimondii have been identified respectively.2. Synteny analysis indicated that segmental and tandem duplication contributed to the expansion of the RB-GRP family between G. arboreum and G. raimondii.3. Tandem duplicated genes in G. arboreum and G. raimondii mapped into syntenic blocks indicated that these genes shared a common ancestral gene.4. Furthermore, evolutionary analysis of RB-GRP orthologous genes pairs between G. arboreum and G. raimondii suggested that most RB-GRP genes in cotton species had undergone stronger negative selective pressure.5. Expression profiles of RB-GRP genes in G. arboreum and G. raimondii in different abiotic stress indicated that they responsed to ABA stress, salt stress and PEG stress. And they conferred stress tolerance to the plant through regulating their expression.In summary, this study identified 37 and 32 RB-GRP genes from G. arboreum and G. raimondii, respecitively. Segmental and tandem duplication are the main mechanism leading to the gene family expansion. Diploid cotton RB-GRP are involved in plant responses to ABA stress, Na Cl stress and PEG stress. And they conferred stress tolerance to the plant through regulating their expression. The results provided a theoretical basis for development of the function of RB-GRP in cotton.