枳水通道蛋白TIP基因家族成员的克隆及其在硼胁迫下的表达分析

In order to study the relationship of Aquaporins TIP gene family and boron transportation in trifoliate orange [Poncirus trifoliata(L.)Raf.]. Eight numbers of TIP subfamily gene were cloned which included five subgroups and analyzed by using Bioinformatics. We found that, PtrTIPs genes were located on three different branches in phylogenetic tree which PtrTIP2s and PtrTIP5s are located on two different branches perfectively while another three subgroup members are located on another branch in phylogenetic tree. Their amino acid sequences were consisted of six alpha-helical transmembrances and two conserved NPA（Asn-Pro-Ala）motifs as well as Characteristic signal sequence（-SGGHINPAVTFG）by aligning sequences. Analysis of tissue specificity, it revealed that most of gene members were epressed in root besides PtrTIP5;1was in steam, none was in leaf. The RT-PCR analysis of PtrTIPs gene family in different organs under boron stress were studied, we found that most of gene members responsed strongly to boron stress in root and had a high relatively expression levels while PtrTIP5;1responsed in steam, meanwhile the sites responsing to stress were accordanced with its organ specificity. The relative expression levels of PtrTIP3;2was very low and it mainly did not response to boron stress. So we guessed that the members of PtrTIPs gene family maybe participate in the process of responsing to boron stress, in order to further clarify the molecular mechanism of responsing to boron stress in citrus and provides theoretical basis.