Genome wide Association Analysis

Plant β-galactosidases (BGALs) are the important glycosidase that hydrolyses the non-reductive terminaβ-D-galactosidase residues from glycochains, glycolipids and glycoproteins. In order to reveal the regulation mechanism of β-galactosidases in cotton development, the whole genome analysis of BGAL gene family were carried out in this study, which laid a foundation for further understanding of the function of BGAL genes in cotton pollen. A total of 153 BGAL genes were respectively identified in Gossypium hirsutum, G.barbadense, G.arboreum , G.raimondii . Phylogenetic tree analysis showed that the BGAL genes are divided into eight subgroups, with the same number of exons and genetic structure in the same subgroup. The co-evolutionary analysis showed that there were multiple gene pairs between G.hirsutum and diploid cotton. The transcriptomic data showed that some genes in G.hirsutum were specifically expressed in different tissues. For example, GhBGAL6 and GhBGAL32 , are highly expressed in all tissues; GhBGAL33 , GhBGAL7 , GhBGAL18 and GhBGAL43 were highly expressed in stamens (anther and filament) and petals. Further qRT-PCR results showed that some genes (such as GhBGAL6 , GhBGAL7 and GhBGAL17 ) were highly expressed in stamens, which may have a certain regulatory effect on the development of stamens. This study explored the evolution and function of the BGAL gene family in the genomes of cotton, which can provide a theoretical basis for subsequent research on BGAL genes in cotton.