植物学

植物学

来源出版物：Journal of Integrative Plant Biology，2015，57（7）： 618-627

联系邮箱：Christine Böttcher，christine.bottcher@csiro.au

水稻POR基因的分离、定位与功能的初步研究

高小丽，李素娟，邵健丰，等

本研究发现水稻ygl3（yellow green leaf3）突变体苗期的叶片呈黄绿色；在营养生长后期，ygl3叶片从叶尖开始严重褪色，形成黄斑或白斑.图位克隆结果表明，YGL3编码一个定位于叶绿体的原叶绿素酸酯氧化还原酶B（OsPORB），转基因互补实验证实了图位克隆的结果.水稻基因组中存在两个POR基因OsPORA和OsPORB.RT-PCR分析表明，OsPORA主要在新生的茎、叶和穗中表达，而OsPORB为组成型表达.亚细胞定位分析发现OsPORA和OsPORB为叶绿体定位蛋白.此外，用35S启动子驱动OsPORA表达能够完全互补ygl3的表型.虽然利用RNAi技术抑制OsPORA表达的转基因水稻叶片与野生型呈现一样的表型，但在ygl3背景下，抑制OsPORA的表达导致转基因水稻黄化致死，说明OsPORA和OsPORB为叶绿素合成所必需的.以上研究结果说明OsPORA和OsPORB在功能上具有一定的冗余性，但OsPORB比OsPORA的作用更重要，揭示了OsPOR在叶绿素合成途径上保守性.

水稻；叶绿素合成；OsPOR；图位克隆；叶绿体

来源出版物：植物生理学报，2015，51（6）： 860-868联系邮箱：刘洪家，lhjzju@aliyun.com

封面介绍：The hormone jasmonic acid（JA）is activated by conjugation to isoleucine. In this issue，Bötcher et al.（pp. 618-627）analyze two grapevine JAamido synthetases，VvGH3-7 and VvGH3-9，for their roles in JA-Ile conjugate biosynthesis，berry development and stress responses. In leaves，VvGH3-9 is wounding-and JA-responsive，while VvGH3-7 seems to be induced by a mobile wounding signal.

Jasmonic acid-isoleucine formation in grapevine（Vitis vinifera L.）by two enzymes with distinct transcription profiles

Christine Böttcher，Crista A. Burbidge，Valentina di Rienzo，et al.

The plant hormone jasmonic acid（JA）is essential for stress responses and the formation of reproductive organs，but its role in fruit development and ripening is unclear. Conjugation of JA to isoleucine is a crucial step in the JA signaling pathway since only JA-Ile is recognized by the jasmonate receptor. The conjugation reaction is catalyzed by JA-amido synthetases，belonging to the family of Gretchen Hagen3（GH3）proteins. Here，in vitro studies of two grapevine（Vitis vinifera L. cv Shiraz）GH3 enzymes，VvGH3-7 and VvGH3-9，demonstrated JA-conjugating activities with an overlapping range of amino acid substrates，including isoleucine. Expression studies of the corresponding genes in grape berries combined with JA and JA-Ile measurements suggested a primary role for JA signaling in fruit set and cell division and did not support an involvement of JA in the ripening process. In response to methyl JA（MeJA）treatment，and in wounded and unwounded（distal）leaves，VvGH3-9 transcripts accumulated，indicating a participation in the JA response. In contrast，VvGH3-7was unresponsive to MeJA and local wounding，demonstrating a differential transcriptional regulation of VvGH3-7 and VvGH3-9. The transient induction of VvGH3-7 in unwounded，distal leaves was suggestive of the involvement of an unknown mobile wound signal.

Berry development；GH3；grapevine；jasmonic acid；wound response