基于羊草种子转录组中PGM及SUS基因家族鉴定与分析

Identification and Analysis of PGM and SUS Gene Families in Leymus chinensis Seed Transcriptome

羊草(Leymus chinensis(Trin.)Tzvel.)是多年生优质饲草,具有适口性好、产量高、饲用价值高等特点。此外,由于羊草具有较强的抗性,因而能够改善土地贫瘠等劣势环境,是保护中国草地生态的重要建群种。为促进羊草种子萌发,探究萌发机理,本研究以无菌水处理羊草种子为对照,外源添加GA3为处理条件,基于前期转录组数据分析,确定了蔗糖和淀粉代谢通路中的PGM及SUS基因在种子萌发过程中有着显著作用。采用生物信息学的分析方法分别分析了两个基因家族的成员鉴定、保守结构域以及进化树,并结合FPKM值对PGM及SUS基因进行表达模式分析。结果表明:基于羊草种子转录组数据筛选出PGM及SUS基因家族的成员均为7个,PGM基因的分子量大小在15471.3~67912.9 Da,等电点数值大小在4.45~6.31,呈弱酸性。羊草种子中PGM家族均为亲水稳定蛋白。而SUS基因的分子量大小在30421.5~110262.9 kD,等电点除LcSUS1、LcSUS5、LcSUS7偏中性外,而其余的4个基因则偏弱酸性。LcSUS4、LcSUS6为稳定亲水蛋白,其余的为不稳定亲水蛋白。羊草种子中PGM及SUS基因家族在蔗糖和淀粉代谢通路中起到促进蔗糖和淀粉合成的基因酶作用。对羊草种子表达模式分析发现,GA3处理羊草种子PGM及SUS基因家族的基因通过不同表达量的正负调控蔗糖和淀粉通路来共同作用促进羊草种子萌发。

Leymus chinensis is a good perennial forage with good palatability,high yield and high feeding value.In addition,because of its strong resistance,Leymus chinensis can improve the disadvantaged environment such as poor land,and it is an important species to protect grassland ecology in China.Therefore,in order to promote the germination of Leymus chinensis seeds and explore the mechanism of germination,this study used sterile water treatment of Leymus chinensis seeds as control,exogenous GA3as treatment conditions.Based on the analysis of pre-transcriptome data,it was determined that PGM and SUS genes in sucrose and starch metabolic pathways play a significant role in seed germination.Members identification,conserved domains,and evolutionary trees were analyzed for both gene families using the bioinformatics method.The expression pattern of PGM and SUS genes were analyzed with FPKM value.The results showed that 7 members were selected from each of the the PGM and SUS families based on the data of Leymus chinensis seeds transcriptome.The molecular weight of PGM genes ranged from 15471.3 to 67912.9 Da,and the isoelectric point value ranged from 4.45 to 6.31,showing weak acidity.PGM family in Leymus chinensis seeds are hydrophilic stable proteins.The molecular weight of SUS genes ranged from 30421.5 to 110262.9 Da.The isoelectric point of SUS genes were neutral except LcSUS1,LcSUS5 and LcSUS7,while the other four genes were weak acidic.LcSUS4,LcSUS6 were stable hydrophilic proteins,the rest were unstable hydrophilic proteins.The PGM and SUS gene families in Leymus chinensis seeds play an enzyme role in promoting sucrose and starch synthesis in sucrose and starch metabolism pathways.The expression pattern analysis of Leymus chinensis seeds showed that the genes of PGM and SUS gene families in GA3-treated Leymus chinensis seeds promoted the germination of Leymus chinensis seeds by regulating the sucrose and starch pathways with different expression levels.