狗蔷薇生长素输出载体蛋白基因PIN1 和PIN2的分离与表达分析

 植物体内生长素输出载体PIN 蛋白基因的表达变化间接反映了生长素的运输与积累状态。为分析生长素在狗蔷薇（Rosa canina）类原球茎发生初期的作用，以狗蔷薇叶片愈伤形成的不定根为材料，分离了生长素输出载体蛋白基因PIN1 和PIN2 的cDNA，分别命名为RcPIN1（GenBank 登录号KF543362）和RcPIN2（GenBank 登录号KF543363）。RcPIN1 全长2 266 bp，编码621 个氨基酸；RcPIN2全长2 248 bp，编码643 个氨基酸，两者推导蛋白结构差异微小，在N 端和C 端均有5 个跨膜区域，中间1 个亲水区。Blast 比对发现两个基因与多种植物PIN 基因具有高度同源性（> 70%）。半定量RT-PCR分析表明，RcPIN1 在根、茎中表达量高于叶和花，RcPIN2 在根中表达水平高于茎、叶和花；在狗蔷薇类原球茎发生初期，TDZ 诱导培养下愈伤—不定根RcPIN1 和RcPIN2 表达上调，而TDZ + TIBA 抑制培养下两基因表达不活跃，且类原球茎形成率降低。试验结果表明生长素的极性运输与积累参与了调控狗蔷薇类原球茎的初期形态建成。

Cloning and Expression Analysis of PIN1 and PIN2 Encoding Auxin Efflux Carriers in Rosa canina

The auxin transport and accumulation in plant can be indirectly indicated by the expressionlevel of PIN（PIN-FORMED）genes encoding auxin efflux carriers. To identify the role of auxin in theinitial development of Rosa canina protocorm-like body（PLB），two PIN genes RcPIN1（GenBank No.KF543362）and RcPIN2（GenBank No. KF543363）were isolated from adventitious roots of R. caninacallus. The full cDNA of RcPIN1 was 2 266 bp in length and encoded a protein of 621 amino acids，that ofRcPIN1 was 2 248 bp and encoded 643 amino acids，and they demonstrate a relatively high similarity inthe two groups of membrane-spanning domains，located at the N- and C-termini of the proteins，and high heterogeneity in the central hydrophilic region. Blast exhibited that RcPIN1 and RcPIN2 were highlyhomologous to other PINs（> 70%）. Semi-quantitative RT-PCR analysis showed that the expression levelof RcPIN1 was higher in the root and stem than the leaf and flower，while that of RcPIN2，the root than thestem，leaf and flower. During the initial occurrence of R. canina PLB，high expression of RcPIN1 andRcPIN2 was induced in the callus-roots by TDZ culture，while in the presence of TIBA the two genes wereinactive and less PLB formed finally. Our data suggested that auxin plays a important roles during theinitial morphogenesis of R. canina PLB.