史翔宇 龙翔宇 方永军 阳江华 肖小虎 秦云霞

摘  要：根瘤素26-like内在蛋白（nodulin 26-like intrinsic proteins， NIPs）是水通道蛋白（aquaporin protein， AQP）中一个植物特有的亚类，主要定位在质膜或内质网膜上，负责转运不带电荷的类金属溶质如硼、甘油、尿素、硅、砷、H2O2、NH3等，在植物营养获取或胁迫应答过程中发挥着重要作用。本研究以拟南芥NIPs序列为参照，利用多种生物信息学软件，对橡胶树7个HbNIPs的基因结构、蛋白理化性质、聚类分析、组织表达及割胶处理的应答进行综合分析。根据分析结果可以初步推断：7个HbNIPs应是有功能的转运蛋白，它们不但具有AQP典型的跨膜结构域（4～6个），保守的NPA基序和关键的ar/R筛选氨基酸，而且从聚类的结果可以推断它们具有转运硼酸、尿素和乳酸的功能。另外，从其启动子调控元件、表达分析和翻译后修饰分析可知，它们的活性及表达具有受发育阶段、多种激素和磷酸化修饰的严谨调控。该初步结果有助于进一步研究橡胶树NIP家族基因的功能及其在橡胶树创新育种中的应用。

关键词：橡胶树;根瘤素26-like内在蛋白;水通道蛋白;类金属元素

Abstract： Nodulin 26-like intrinsic proteins （NIPs） are one subclass of plant specific aquaporin protein （AQP）， mainly located at cytoplasm or endoplasmic reticulum， in charge of exchange metalloids such as boron， silicon， arsenic， selenium， glycerol， carbamide， H2O2， NH3 etc.， which are indispensible for plant microelement nutrition and stress responses. In this study， seven NIPs homologues of Arabidopsis were screened out on the rubber tree whole genome level， then bioinformations of their gene structure， protein domains and motifs， promter cis-acting elements and expression characteristics were in-depth analyzed through on-line softwares and PRISM. Totally， the seven HbNIPs were putative functional NIPs， because they owned all or partial typical characteristics of AQPs and clustered together with the homologues， such as typical domains for transmembrane， conservative NPA motifs and key ar/R amino acid for substrate determination. From the phylogenetic analysis results， they were predicated to be possibly involved in metalloids assimilation such as boron or glycerol， or lactate. In addition， from the analyses of cis-acting elements in the promoters， expression profiles and post-translational modifications， it is obvious that the activities would be critically regulated by development stages or hormones or phosphorylation. The primary results would benefit for further study on the function and utilization in rubber trees innovative breeding.

Keywords： Hevea brasiliensis; nodulin 26-like intrinsic proteins; aquaporin protein， AQP; metalloid

水通道蛋白（aquaporin protein， AQP）的重要性已經为人们所熟知，它们通过调节水分的吸收和转运，能够快速调节细胞体积、渗透压等，维系着细胞的生命和整个植物的水分平衡。它们如此重要而不断进化为成员众多，功能多样的主要内在蛋白MIP（major intrinsic protein）大家族。依据其亚细胞定位及氨基酸序列的同源性分为4大亚类：质膜内在蛋白（plasma membrane intrinsic proteins， PIPs），液泡膜内在蛋白（tonoplast intrinsic proteins， TIPs），根瘤素26-like内在蛋白（NOD26-like Intrinsic Proteins， NIPs）以及小分子碱性内在蛋白（small basic intrinsic proteins， SIPs）[1]。……