Abbal Philippe, Pradal Martine, Muniz Lisa, Sauvage François-Xavier, Chatelet Philippe, Ueda Takashi, Tesniere Catherine
UMR1083, Sciences pour l'Oenologie, INRA, 2 Place Viala, F-34060 Montpellier cedex 1, France.
J Exp Bot. 2008;59(9):2403-16. doi: 10.1093/jxb/ern132. Epub 2008 May 21.
As a first step to investigate whether Rab GTPases are involved in grape berry development, the Vitis vinifera EST and gene databases were searched for members of the VvRab family. The grapevine genome was found to contain 26 VvRabs that could be distributed into all of the eight groups described in the literature for model plants. Genetic mapping was successfully performed; VvRabs were mostly located on independent chromosomes, apart from eight that were located on the as yet unassigned portions of the genome clustered in the ChrUn Random chromosome. Conserved and divergent regions between VvRab protein sequences were identified. Transcript expression of 11 VvRabs was analysed by real-time quantitative RT-PCR. Except for VvRabA5b, transcript expression was detected, in general, in all the organs investigated, but with different patterns. In grape berries, VvRab transcripts were expressed at all stages of fruit development, with different profiles, except in the case of members of the A family which displayed generally similar patterns. The response to growth regulators in cell cultures was generally specific to each VvRab, with a differential pattern of expression for ethylene, auxin, and abscisic acid according to the VvRab. Interestingly, and unexpectedly considering transcript expression, western blotting using a monoclonal antibody raised against AtRabA5c (ARA4) showed a specific expression in the exocarp of ripe grape berries, in all seven red and white berry varieties tested. By contrast, no expression was detected in any of the other organs or tissues investigated. This paper contains the first description of Rab GTPases in V. vinifera. The involvement of a specific VvRab in grape berry late development and the potential role of this Rab GTPase are discussed in relation to literature data.
作为研究Rab GTPases是否参与葡萄果实发育的第一步，我们在葡萄（Vitis vinifera）EST和基因数据库中搜索VvRab家族成员。发现葡萄基因组包含26个VvRabs，它们可被归入文献中描述的模式植物的所有八个组。成功进行了遗传定位；VvRabs大多位于独立染色体上，只有八个位于基因组中尚未分配的部分，这些部分聚集在ChrUn随机染色体上。鉴定了VvRab蛋白序列之间的保守和差异区域。通过实时定量RT-PCR分析了11个VvRabs的转录本表达。除VvRabA5b外，一般在所有研究的器官中都检测到了转录本表达，但模式不同。在葡萄果实中，VvRab转录本在果实发育的所有阶段都有表达，模式各异，除了A家族成员显示出大致相似的模式。细胞培养物中对生长调节剂的反应通常对每个VvRab都是特异的，乙烯、生长素和脱落酸的表达模式因VvRab而异。有趣的是，考虑到转录本表达情况出乎意料的是，使用针对AtRabA5c（ARA4）产生的单克隆抗体进行的蛋白质印迹显示，在所有测试的七个红葡萄和白葡萄品种的成熟葡萄果实外果皮中有特异性表达。相比之下，在任何其他研究的器官或组织中均未检测到表达。本文首次描述了葡萄中的Rab GTPases。结合文献数据讨论了特定VvRab在葡萄果实后期发育中的作用以及该Rab GTPase的潜在作用。
