植物學(xué)

植物學(xué)

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

聯(lián)系郵箱：Christine B?ttcher，christine.bottcher@csiro.au

水稻POR基因的分離、定位與功能的初步研究

高小麗，李素娟，邵健豐，等

本研究發(fā)現(xiàn)水稻ygl3（yellow green leaf3）突變體苗期的葉片呈黃綠色；在營養(yǎng)生長后期，ygl3葉片從葉尖開始嚴(yán)重褪色，形成黃斑或白斑.圖位克隆結(jié)果表明，YGL3編碼一個(gè)定位于葉綠體的原葉綠素酸酯氧化還原酶B（OsPORB），轉(zhuǎn)基因互補(bǔ)實(shí)驗(yàn)證實(shí)了圖位克隆的結(jié)果.水稻基因組中存在兩個(gè)POR基因OsPORA和OsPORB.RT-PCR分析表明，OsPORA主要在新生的莖、葉和穗中表達(dá)，而OsPORB為組成型表達(dá).亞細(xì)胞定位分析發(fā)現(xiàn)OsPORA和OsPORB為葉綠體定位蛋白.此外，用35S啟動(dòng)子驅(qū)動(dòng)OsPORA表達(dá)能夠完全互補(bǔ)ygl3的表型.雖然利用RNAi技術(shù)抑制OsPORA表達(dá)的轉(zhuǎn)基因水稻葉片與野生型呈現(xiàn)一樣的表型，但在ygl3背景下，抑制OsPORA的表達(dá)導(dǎo)致轉(zhuǎn)基因水稻黃化致死，說明OsPORA和OsPORB為葉綠素合成所必需的.以上研究結(jié)果說明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在葉綠素合成途徑上保守性.

水稻；葉綠素合成；OsPOR；圖位克隆；葉綠體

來源出版物：植物生理學(xué)報(bào)，2015，51（6）： 860-868聯(lián)系郵箱：劉洪家，lhjzju@aliyun.com

封面介紹：The hormone jasmonic acid（JA）is activated by conjugation to isoleucine. In this issue，B?tcher 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 B?ttcher，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