大豆LBD基因家族的鉴定与表达分析

Genome-wide identification and expression analysis of LBD gene family in soybean

转录因子是植物生长发育的重要调节因子。侧生器官边界域(LBD,Lateral organ boundaries domain)基因家族是一类植物特有的转录因子,参与植物生长、营养代谢和逆境胁迫响应的调控。本研究采用生物信息学方法,从基因组和转录组水平对大豆LBD基因家族进行了系统鉴定和表达模式分析。系统进化结果显示,大豆LBD基因家族的89个成员可分为2大类、7个亚族。理化性质分析显示,大豆LBD基因家族编码的氨基酸数量范围在50 aa~325 aa,分子量为8 164.16 Da~60 499.65 Da,等电点介于4.69 pl~9.15 pl,不稳定系数为43.46~83.94。Motifs和基因结构分析发现,LBD基因家族成员保守性较高。启动子顺式作用元件分析显示,LBD基因家族成员含有与植物光响应相关的29种顺式作用元件,与植物激素相关的11种元件,以及与非生物和生物胁迫响应相关的6种元件。转录组分析发现,大豆LBD基因在DN50品种的生长节间伸长区(EZ)、成熟区(MZ)和茎尖(ST)的表达模式存在差异。LBD家族成员主要在MZ和ST高表达,其中GmLBD5、GmLBD23、GmLBD38、GmLBD46、GmLBD49、GmLBD71、GmLBD75和GmLBD78在EZ、MZ和ST均高表达,是调控大豆株高的关键候选基因。同时,还发现一些基因在茎组织特异表达,例如GmLBD83在EZ表达量较高,而GmLBD15、 GmLBD59、 GmLBD61和GmLBD84只在MZ高表达,GmLBD14、 GmLBD18、 GmLBD21、 GmLBD27、GmLBD55、GmLBD66和GmLBD70只在ST高表达。研究结果为深入分析LBD基因调节大豆节间生长发育的分子机理提供了靶标基因。

Transcription factor plays an important role in plant growth and development.The LBD(lateral organ boundaries domain)gene family is a group of plant-specific transcription factors that play key roles in the regulation of plant growth,nutrient metabolism,and response to adversity stress.In this study,the soybean LBD gene family was systematically identified and analyzed for expression patterns at the genomic and transcriptomic levels using bioinformatics methods.The phylogenetic results show that the 89 members of the soybean LBD gene family are classified into 2 major classes and 7 subfamilies.The analysis of physicochemical properties shows that the amino acid numbers encoded by the soybean LBD gene family range from 50 aa to 325 aa,the molecular weights range from 8164.16 Da to 60499.65 Da,the isoelectric points range from 4.69 pl to 9.15 pl,and the coefficients of instability range from 43.46 to 83.94.Motifs and gene structure analysis reveal that the LBD gene family members are highly conserved.Promoter cis-acting element analysis shows that the LBD gene family members contain 29 cis-acting elements related to plant light response,11 elements related to phytohormones,and 6 elements related to abiotic and biotic stress response.Transcriptome analysis reveals that the soybean LBD genes are differentially expressed in the elongation zone(EZ),mature zone(MZ),and stem tip(ST)of the growing internodes of DN50.LBD family members are highly expressed mainly in MZ and ST,among which GmLBD5,GmLBD23,GmLBD38,GmLBD46,GmLBD49,GmLBD71,GmLBD75,and GmLBD78 are highly expressed in EZ,MZ,and ST,which are the key candidate genes to regulate the height of soybean plants.Some genes are found to have expression specificity in stem tissues,for example,GmLBD83 is highly expressed in the EZ,whereas GmLBD15,GmLBD59,GmLBD61,and GmLBD84 are only highly expressed in the MZ,and GmLBD14,GmLBD18,GmLBD21,GmLBD27,GmLBD55,GmLBD66,and GmLBD70 are only highly expressed in ST.The results of this study provide candidate genes for in-depth analysis of the molecular mechanism of LBD genes in regulating the growth and development of soybean internodes.