桑树EIN2基因的分离与表达

EIN2是植物体内乙烯信号转导的中心元件，负责将乙烯信号由内质网传递到细胞核中。本文通过检索桑树基因组数据，获得一个EIN2候选基因(MaEIN2)，并进行生物信息学分析和表达分析。该MaEIN2全长5614 bp，由7个外显子和6个内含子组成，包含3921 bp的CDS，编码1036个氨基酸残基。MaEIN2在进化树中与草莓、桃树等双子叶植物的EIN2蛋白关系较近，与单子叶植物关系较远。MaEIN2在老叶和成熟果实中的表达量分别高于在幼叶和幼果中，且随果实发育呈逐渐上升趋势，MaEIN2可能与器官的成熟衰老有关。选用乙烯利、ABA和NaCl处理桑树种苗，乙烯利能够促进MaEIN2的表达，而ABA和NaCl抑制MaEIN2的表达。本文为深入研究MaEIN2基因的功能奠定了基础。

Isolation and Expression of Mulberry (Morus alba L.) EIN2 Gene

EIN2 is a central component of ethylene signaling pathway, transferring the ethylene signal from endoplasmic reticulum to nucleus. A putative EIN2 gene obtained from Morus Genome Database and its expression levels were detected by using RT-PCR. The full-length genomic sequence of MaEIN2 is 5614 bp in length, which consists of seven exons and six introns. The CDS of MaEIN2 is 3921 bp and encodes 1036 amino acids. Phylogenetic tree analysis revealed that MaEIN2 had closer relationships with dicotyledons plants and further with monocotyledons plants. The expression levels of MaEIN2 in old leaf and mature fruit were much higher than these in young leaf and immature fruit. The expression levels of MaEIN2 was increasing gradually in fruit development, indicating MaEIN2 was involved in the ripening and senescence of plant organs. Ethephon, ABA and NaCl were used to incubate the mulberry seeds, showing that ethephon induced the expression of MaEIN2 in seedlings, while ABA and NaCl downregulated the expression of MaEIN2. This work lays a foundation for further understanding of the function of MaEIN2.