杨树LEA基因家族全基因组鉴定及表达分析

On Genome-scale Identification and Expression Analysis of LEA Genes in Poplar

从杨树基因组中鉴定LEA蛋白家族成员,并分析基因在杨树各组织以及在种子形成、吸涨及萌发过程中的表达情况.从NCBI下载拟南芥、水稻以及大豆等植物的LEA蛋白家族成员,通过blastP程序从杨树基因组中鉴定出候选基因,并采用pfam程序进行进一步筛选获得杨树LEA蛋白基因,最后通过芯片以及EST数据分析基因的表达量.通过对杨树LEA蛋白基因家族在全基因组水平上的搜索,确定了杨树LEA蛋白家族8个亚家族,共87个成员,发现在花中有16个基因高量表达,且其中8个基因具有很高的组织特异性.在吸涨种子中,PtLEA1.1和PtLEA3.1有高量的表达,LEAⅣ,LEAⅤ,LEAⅥ及SMP亚家族成员都具有特异的表达.12个基因在萌发种子中有高量的表达,其中4个基因特异表达,5个基因在种子萌发过程中可能受到光照的影响.此外,3个基因在成熟叶片中出现了下调表达,8个基因在根中具有高量表达,3个基因的高量表达在木质部中被发现.杨树LEA蛋白不同亚家族成员可能参与了植物种子的生长发育、种子的萌发及对胁迫的响应等多种生理功能.

In our study, LEA gene families have been identified and their expression profiles beenalso bioin formaticaslly analyzed. The sequences of LEA genes in Arabidopsis thaliana, Rice, Glycine max have been downloaded from NCBI web site to search the LEA genes in poplar. Candidate gene have been deter- mined by means ofthe pfam program. Microarray Data and EST have been used to value the expression of LEA genes. According to motif analysis, a total of 87 LEA genes have been systematically identified from poplar classified into 8 subfamilies in our study. 16 LEA genes have been highly expressed in flowers and 8 of them shared tissue specific expression. PtLEA1.1 and PtLEA3.1 have high abundant expression in im bibition seeds, as well as members of subfamilies LEAIV, LEAV, LEAVI and SMP. In germination seeds, 12 LEA genes have beenhighly expressed and 4 of them shared tissue specific expression. The ex- pression of 5 LEA genes has beeninvolved with light during the germination. 3 LEA genes share down reg- ulated expression in mature leaves. 8 LEA genes havehigh expression in root and 3 LEA genes in xylem. These resuhssuggest each subfamily of LEA have their function in different stages of seeds. High expres- sionof LEA genesare detected in formation and germination of seeds and these genes may play important roles in the development of seeds, not only formation but also germination.