大蒜MtN3/saliva/SWEET基因家族的全基因组鉴定及表达分析

Genome-wide identification and expression analysis of the MtN3/saliva/SWEET gene family in Allium sativum L.

探究大蒜AsSWEETs基因家族特征和生物学功能,可为大蒜鳞茎发育调控的分子机制提供参考。本研究基于大蒜“二水早”全基因组数据,通过HMM搜索对AsSWEETs成员进行筛选和鉴定,并利用实时荧光定量PCR分析其在不同激素处理下的表达模式。结果表明:在大蒜基因组中共鉴定到35个AsSWEETs基因,均为疏水蛋白,含2~7个不等的跨膜螺旋,除AsSWEET 1、AsSWEET 2位于scaffold外,其余均分布于染色体上,成员间差异显著。综合系统进化和表达模式发现,AsSWEET5、14、21、23、26、28(第III支系,转运蔗糖)可能是参与鳞茎膨大的主要调控基因;AsSWEET 2、30、33(IV分支)的表达量在鳞茎发育不同阶段变化较大,可能参与鳞茎发育过程中的果糖代谢调节。qRT-PCR定量表明,在不同激素处理下,AsSWEET5、11、16呈现出不同的表达模式,预示AsSWEETs家族成员功能存在分化和差异。综上,大蒜AsSWEET s基因的糖转运活性参与了鳞茎的生长发育,有助于解释鳞茎膨大发育过程。

The exploration of the characteristics and biological functions of the AsSWEETs gene family in Allium sativum L.is a way to provide reference for the molecular mechanism of its bulb development regulation.Based on the whole genome data of Allium sativum L."Ershuizao",members of As-SWEETs are screened and identified through HMM search.Their expression patterns under different hormones are analyzed by adopting real-time fluorescence quantitative PCR.The results indicate that a total of 35 AsSWEETs genes are identified in the Allium sativum L.genome,all of which are hydrophobic proteins with 2~7 different transmembrane helices.Except for AsSWEET1 and As-SWEET2 located in scaffold,the rest are distributed on chromosomes with significant differences among members.Through comprehensive systematic evolution and expression patterns,it is found that AsSWEET5,14,21,23,26,28(Ⅲbranch,transporting sucrose)may be the main regulatory gene involved in the bulb enlargement.The expression levels of AsSWEET 2,30 and 33(Ⅳbranch)vary greatly at different stages of bulb development,which may be involved in the regulation of fructose metabolism during the bulb development.According to qRT-PCR quantitative analysis,AsSWEET5,11 and 16 show different expression patterns under different hormone treatments,indicating that there may be differentiation and differences in the functions of AsSWEETs family members.In summary,the sugar transport activity of Allium sativum L.AsSWEETs gene is involved in the growth and development of bulb,which helps explain the process of bulb enlargement and development.