香蕉水通道蛋白基因的克隆与表达分析

目的]更好了解香蕉果实与水分代谢的关系。方法]依据从抑制差减杂交文库(SSH)中获得的一个cDNA序列,设计5′和3′RACE引物,从香蕉果实中扩增基因5′和3′末端片段,并用RT-PCR的方法探讨该基因在香蕉各组织中的表达情况。结果]获得一个1 132 bp的水通道蛋白全长基因,命名为MaPIPl;1。MaPIPl;1基因包含861 bp的完整阅读框架,编码的蛋白有6个跨膜结构及aspara-gine-proline-alanine(NPA)和aromatic/arginine 2个保守区。其与水稻水通道蛋白基因OsPIP1;2在氨基酸序列上有94.1%的一致性和97.9%的相似性。且MaPIP1;1在香蕉各器官中均稳定表达。结论]MaPIPl;1可能与香蕉的水分代谢相关。

Analysis of the Clone and Expression of the Aquaporin Gene of Banana

Objective] The relationship between banana fruit and water metabolism was understood.Method] Based on suppression subtractive hybridization from the library(SSH),a cDNA sequence was obtained,5′and 3′ RACE primers were designed;and then,the gene fragments at the 5′and 3′ end were amplified in the banana fruit and RT-PCR method was used to explore the gene expression in banana organizations.Results]A 1 132 bp cDNA with 861 bp open reading frame encoding a 286 amino acids aquaporin ortholog,named MaPIPl;1,was successfully cloned and characterized from the fruit of banana(Mu sa sp.,AAA group,Cavendish subgroup,cultivar 'Williams').The deduced MaPIP1;1 protein contained six putative transmembrane domains with two highly conserved motifs of asparagine-proline-alanine(NPA) and aromatic/arginine(ar/R) region found in the major intrinsic protein(MIP) family.The MaPIP1;1 exhibited the sequence identity to rice gene OsPIP1;2(94.1%).Semi-quantitative RT-PCR revealed that MaPIPl;1 was constitutively expressed in all of the tissues of banana.Conclusion]There could be a relationship between was MaPIPl;1 and water metabolism of banana fruit.