棉花β-半乳糖苷酶基因家族的全基因组鉴定及分析

Genome-wide Identification and Analysis of Cottonβ-Galactosidase Gene Family

植物β-半乳糖苷酶(β-galactosidase,BGALs)是一类重要的糖苷水解酶,可水解糖链、糖脂及糖蛋白中非还原末端β-D-半乳糖残基。为揭示β-半乳糖苷酶在棉花发育中的调控机制,本研究对BGAL家族做全基因组学分析,为进一步了解BGAL家族在棉花花粉中的功能提供理论支持。利用生物信息学对陆地棉、亚洲棉、海岛棉和雷蒙德氏棉这四个棉种的BGAL进行成员鉴定、序列特征、保守域结构、共进化关系等家族特征分析,并进一步利用转录组数据和RT-qPCR分析GhBGALs基因在不同组织中的表达模式。共鉴定153个BGAL家族成员,利用聚类分为8个亚组,同一亚组中具有相似的外显子/内含子数目和基因结构,共进化分析中显示在陆地棉和二倍体棉属间存在多对基因对,转录组数据结果表明陆地棉中的部分基因在不同组织中特异性表达,例如GhBGAL6和GhBGAL32这两个基因在所有组织中都高表达;GhBGAL33、GhBGAL7、GhBGAL18和GhBGAL43这四个基因在雄蕊(花药和花丝)和花瓣中表达量极高,进一步的RT-qPCR实验结果发现,部分基因(如GhBGAL6,GhBGAL7,GhBGAL17)在雄蕊中高表达,推测此类基因对雄蕊的发育有一定的调控作用。本研究首次对BGAL家族在陆地棉、亚洲棉、海岛棉和雷蒙德氏棉4个棉种进行全基因组鉴定分析,为进一步探索β-半乳糖苷酶对棉花的生长发育提供理论基础。

Plantβ-galactosidases(BGALs)are the important glycosidase that hydrolyses the non-reductive terminalD-galactose residues from glycochains,glycolipids and glycoproteins.In order to reveal the regulation mechanism ofβ-galactosidases in cotton development,the whole genome analysis of BGAL family genes was 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 members of the BGAL family were identified in Gossypium hirsutum,G.barbadense,G.arboreum,G.raimondii,respectively.Phylogenetic tree analysis showed that the BGAL family is 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 upland cotton and diploid cotton.The transcriptomic data showed that some genes in upland cotton were specifically expressed in different tissues.For example,GhBGAL6 and GhBGAL32,were highly expressed in all tissues;GhBGAL33,GhBGAL7,GhBGAL18 and GhBGAL43 were highly expressed in stamens(anther and filament)and petals.Further RT-qPCR 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.In this study,the whole genome of BGAL family in Gossypium hirsutum,G.barbadense,G.arboreum,G.raimondii was identified for the first time,providing a theoretical basis for further exploration ofβ-galactosidase on the growth and development of cotton.