Metabolic engineering of proanthocyanidins through co-expression of anthocyanidin reductase and the PAP1 MYB transcription factor
Metabolic engineering of proanthocyanidins through co-expression of anthocyanidin reductase and the PAP1 MYB transcription factor
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DOI：
10.1111/j.1365-313x.2006.02655.x
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发表时间：
2006-03-01
期刊：
影响因子：
7.2
通讯作者：
Dixon, RA
中科院分区：
文献类型：
--
作者：
Xie, DY;Sharma, SB;Dixon, RA
原花青素(PAS)及其单体组成单元(Epi)-黄烷-3-醇是一种植物抗氧化剂，对人体健康有多种益处。饲料作物中存在的多胺是一种重要的农艺性状，可以防止反刍动物的牧草膨胀。然而，许多消耗的植物材料缺乏PAS，而且迄今为止，将单体或聚合物黄烷-3-醇从头引入植物组织以通过饮食手段预防疾病或开发“膨大安全”饲料的成功寥寥无几。我们报道了通过MYB家族转录因子和花青素还原酶的联合表达将PAS导入植物，以将花青素转化为(Epi)-黄烷-3-醇。同时表达转基因的烟草叶片积累了表儿茶素和半乳糖儿茶素单体，以及一系列主要由表儿茶素单位组成的二聚体和寡聚体。PAS的水平达到了可以减少饲料物种膨大的值。花青素还原酶在含花色苷的豆科牧草紫花苜蓿叶片中的表达导致了PA低聚体的特定亚群的产生。
Proanthocyanidins (PAs) and their monomeric building blocks, the (epi)-flavan-3-ols, are plant antioxidants that confer multiple human health benefits. The presence of PAs in forage crops is an important agronomic trait, preventing pasture bloat in ruminant animals. However, many consumed plant materials lack PAs, and there has been little success to date in introducing monomeric or polymeric flavan-3-ols de novo into plant tissues for disease prevention by dietary means or development of 'bloat-safe' forages. We report the introduction of PAs into plants by combined expression of a MYB family transcription factor and anthocyanidin reductase for conversion of anthocyanidin into (epi)-flavan-3-ol. Tobacco leaves expressing both transgenes accumulated epicatechin and gallocatechin monomers, and a series of dimers and oligomers consisting primarily of epicatechin units. The levels of PAs reached values that would confer bloat reduction in forage species. Expression of anthocyanidin reductase in anthocyanin-containing leaves of the forage legume Medicago truncatula resulted in production of a specific subset of PA oligomers.