木薯Mlo基因家族成员的鉴定及其序列特征分析

M／o基因家族是植物重要的抗病基因。本文通过系统分析木薯基因组数据库，从中共鉴定出21个M／o成员，其中20个具有完整序列，1个只有部分序列。对其中20个具有完整序列的基因与其他物种的Mlo基因进行聚类关系分析，结果显示，可将木薯Mlo基因家族分为6类（I～VI），其中4类都包括有来自拟南芥的Mlo基因，第vI类只包括2个木薯Mlo基因，可能是木薯中特有的一类Mlo；6个木薯Mlo与已知的抗病Mlo基因分别聚在第1V和第V类，这6个基因可能是木薯基因组中具有抗病功能的Mlo。对所有的木薯Mlo蛋白进行结构分析发现，除了MeMl020外，其他蛋白均具有6～8个跨膜结构，其中3个蛋白具有N端信号肽。

Identification and Sequence Characterization of Mlo Gene Family from the Genome of Manihot esculenta Crantz

Mlo gene family is an important class of plant disease resistance genes. Through systematic analysis of the genome sequence database of Manihot esculenta, total 21 Mlo genes were identified in this study, of which 20 had full-size and one partial sequences. Phylogenetic analysis was performed to reveal the evolution of the cassava Mlo genes with full-size sequences, and Mlo genes from other species. The results indicated that the cas- sava Mlo family could be devided into 6 clades （I-VI）, of which four contained Mlo members from Arabidopsis. The VI clade contained only two cassava Mlo genes, suggested that it might be a specific clade for cassava ge- nome. Furthermore, 6 cassava Mlo genes were grouped into the clades IV and V which contained the Mlo genes of known function in disease resistance, suggested that the 6 cassava Mlo genes might be have their functions in disease resistance. Protein domains analysis revealed that besides MeMlo20, all the other 19 cassava Mlo con- sisted of 6 to 8 membrane-spanning domains, in which 3 proteins contained an N-terminal signal petide.