Molecular Cloning and Sequence Analysis of an Aquapor- in Gene Related to Tapping Panel Dryness in Rubber Tree （Hevea brasiliensis Muell. Arg. ）

摘要

As a syndrome with tapping incision blocked partly or entirely during latex exploiting in rubber tree( Hevea brasiliensis), " Tapping panel dryness( TPD) " causes great yield losses,thereby becoming the most important factor limiting rubber production. On the basis of an EST down-regulated in TPD-affected rubber trees,a 903 bp cDNA denoted HbPIP2; 2 was isolated from the bark tissue with a combination of in silico cloning and RT-PCR. The cDNA contains an 867bp ORF,13 bp 5'UTR and 23 bp 3' UTR. Sequence analysis indicated that HbPIP2; 2 encodes 288 amino acids with a theoretical molecular weight( Mw) of 30.71 kDa and isolectric point( Pi) of 8. 20. Bioinformatics analysis suggested that the deduced protein is predicted to have six transmembrane helices located to the plasma membrane and harbor one conserved MIP domain that can be grouped into plasma membrane intrinsic proteins( PIPs) of aquaporin( AQP) family. Homology search revealed that the protein shares a similarity of more than 90% with the homologues in Ricinus communis,Populus trichocarpa,Juglans regia and Theobroma cacao,supporting a highly conserved evolution. This study provided basis for further uncovering the regulatory role of AQPs in TPD occurrence.