沙冬青胚胎晚期发生丰富蛋白基因序列及表达特性分析

从沙冬青叶片EST文库中获得了胚胎晚期发生丰富蛋白（LEA）基因cDNA全长序列，命名为AmLEA14。序列分析表明该基因全长579 bp，含有一个459 bp编码152个氨基酸的开放阅读框，推测编码的蛋白质分子质量为166 ku。二级结构预测显示此编码蛋白属于第4类LEA蛋白。系统发生分析表明，此编码蛋白与大豆LEA14蛋白（P465191）的亲缘关系最近。荧光定量PCR结果显示，AmLEA14的表达量在低温、干旱、盐胁迫条件下升高，但是主要在低温胁迫后期富集。推测AmLEA14基因可能在沙冬青抵御低温、干旱、盐胁迫中发挥作用，主要是参与沙冬青的低温防御机制。 

Sequence analysis and expression pattern of AmLEA14 encoding a late embryogenesis abundant protein in Ammopiptanthus mongolicus

For a better understanding of stress responses of desert plant Ammopiptanthus mongolicus,we reported molecular characterization and expression analysis of AmLEA14 gene from the EST data of cold-and drought-stressed A.mongolicus.Sequence analysis showed that the overall length of gene AmLEA14 was 579 bp,and the cDNA of AmLEA14 contained a 459 bp ORF encoding a polypeptide of 152 amio acids with a calculated molecular mass of 16.6 kDa and a theoretical pI of 4.9.Sequence and structural analysis showed that AmLEA14 protein was a member of late embryogenesis abundant protein class 4.Phylogenetic analysis indicated that AmLEA14 protein was most closely related to soybean LEA14 protein (P46519.1).Real-time quantitative PCR analysis showed that AmLEA14 was constitutively expressed,up-regulated by cold,drought stressed,and specifically accumulated at the late stage of cold treatment.Otherwise,AmLEA14 was down-regulated by heat stress.The combined results indicate that AmLEA14 protein plays some role in abiotic stress responses,mainly in cold tolerant mechanism,and is valuable for future abiotic stress researches in A.mongolicus.