玉米低磷响应基因ZmPAP18的表达特征与序列变异分析  

Expression and Sequence Variation Analysis of a Low-Phosphorus Responsive Gene ZmPAP18 in Maize

作　　者：苏顺宗[1] 刘丹[1] 吴玲[1] 聂治[1] 张啸[1] 易双[1] 高世斌[1] 

机构地区：[1]四川农业大学玉米研究所,成都611130

出　　处：《分子植物育种》2013年第4期509-516,共8页Molecular Plant Breeding

基　　金：国家973计划(2009CB118400);国家948计划(2011-G15-2);国家自然科学基金(31171566)共同资助

摘　　要：紫色酸性磷酸酶(PAP)是金属磷酸酯酶家族的重要成员,在植物对低磷环境适应的过程中发挥重要作用。依据前期构建的低磷胁迫抑制消减文库,运用RT-PCR方法从耐低磷玉米自交系178中克隆了一个酸性磷酸酶基因的全长序列。该基因编码区全长1409bp,其中ORF为1371bp,编码457个氨基酸残基。经保守域分析发现,基因的推测氨基酸序列中含有紫色酸性磷酸酶所特有的5个保守基序和7个金属离子结合位点,属于紫色酸性磷酸酶类,被命名为ZmPAP18。通过实时荧光定量分析表明,ZmPAP18在根和叶中均受到低磷胁迫的诱导增强表达,且在诱导24h后表达量达到峰值;但在玉米根部的表达量高于叶片,表明ZmPAP18在玉米根部可能参与了根外磷素的活化与吸收以及无机磷由根部向其他组织的转运。此外,经序列分析发现,ZmPAP18的3'非翻译区存在一个Indel(TGTTG)位点,并在常用的14个玉米自交系中表现出丰富的多态性,为进一步开发该基因的分子标记及耐低磷种质分子改良提供了参考信息。Purple acid phosphatase （PAP） is a gene family of metallo-phosphoesterases involved in a variety of physiological functions, especially phosphate （Pi） deficiency adaptations in plants. Based on the cDNA library constructed by SSH for maize seedling root under phosphorus deficiency. A 1 409 bp length gene was cloned from low-phosphate tolerant maize inbred line 178, which encoded 457 amino acid residues. The conserved domain analysis revealed that this cloned gene had five conserved motifs and seven invariant metal-ligating residues typical of known PAPs and therefore named as ZmPAP18. Expression profiles of ZmPAP18 were assayed by fluorescent quantitative PCR and indicated that ZmPAP18 was up-regulated both in seedling root and leaf under phosphate starvation. The expression levels increased in the early stage of Pi starvation, and then continuously increased to the maximal level at 24 h time point. In comparison with seedling leaf, ZmPAP18 was more sensitive and responsive to phosphate starvation in seedling root. These results suggested that ZmPAP18 in maize may be involved in external phosphorus assimilation and transferring inorganic phosphate from root to other tissues. Moreover, an Indel （TGTTG） site was detected in 3＇ UTR of ZmPAP18 and showed highly polymorphism among 14 maize inbred lines, which can be developed as molecular marker to assist improving P utilization in molecular maize breeding.

关 键 词：玉米 ZmPAP18 低磷胁迫 表达分析 序列变异 

分 类 号：S513[农业科学—作物学]