Identification and regulation of the stilbene biosynthetic pathway genes from grapevine

植物二苯乙烯类化合物是一种植物防御素，在许多植物物种中积累，以响应生物和非生物胁迫。近些年来，二苯乙烯类化合物因其对人体健康具有许多有益的作用而受到医学研究的广泛关注。已在至少72种植物中检测到二苯乙烯类化合物，包括花生、蓝莓和葡萄藤等作物。植物不仅在营养器官中积累了大量的二苯乙烯类化合物，而且在水果中也积累了大量的二苯乙烯类化合物，这些水果被用作食物或用于生产果汁和葡萄酒。与所描述的具有不同生物活性的二苯乙烯类化合物的多样性形成鲜明对比的是，到目前为止，只有两种二苯乙烯类化合物被鉴定和表征。考虑到基本二苯乙烯骨架的各种修饰和二苯乙烯的运输，在这些过程中必须存在额外的未知基因和基因产物。此外，二苯乙烯途径在分子水平上的调控也是未知的，直到最近发现了两个专门调节二苯乙烯途径的葡萄转录因子VvMYB14和VvMYB15(Höll等人，2013年)。这些转录因子的过度表达以及随后的微阵列、RNAseq和染色质免疫沉淀(ChIP)分析将在应用研究项目中用于初步鉴定转录因子的靶基因。因此，可以分析二苯乙烯途径的未知基因，并详细研究它们的调控。这些结构基因的异位表达将允许对各自的基因产物进行生化表征。此外，还将研究葡萄品种或物种的遗传差异以及环境因素对二苯乙烯途径的影响，这些都与葡萄二苯乙烯含量的优化有关。因此，这一研究项目将为植物中二苯乙烯途径的分子基础和调控提供新的见解，这一途径仍然知之甚少。关于葡萄品种或物种的遗传差异和环境因素对二苯乙烯代谢的影响的基本结果可以通过后续的葡萄育种方法或适应葡萄栽培实践来优化葡萄二苯乙烯的含量。

Plant stilbenes are phytoalexins that accumulate in a number of plant species in response to biotic and abiotic stresses. In recent years, stilbenes have received widespread attention in medical research because of its implication in many beneficial effects on human health. Stilbenes have been detected in at least 72 plant species including crops like peanut, blueberry and grapevine. Plants accumulate stilbenes in significant amounts not only in vegetative parts, but also in fruits, which are used as food or in the production of juices and wines. In contrast to the large diversity of described stilbenes with different biological activities, only two enzymes of the stilbene pathway have been identified and characterized up to now. Considering the various modifications of the basic stilbene skeleton and the transport of stilbenes additional unknown genes and gene products have to be present for these processes. Also the regulation of the stilbene pathway on the molecular level was unknown untill the recent identification and characterization of the two grapevine transcription factors VvMYB14 and VvMYB15 specifically regulating the stilbene pathway (Höll et al., 2013). Overexpression of these transcription factors and subsequent microarray, RNAseq and chromatin immunoprecipitation (ChiP) analysis will be used in the applied research project to initially identify the target genes of the transcription factors. Thereby, yet unknown genes of the stilbene pathway can be analysed and their regulation be studied in detail. Ectopic expression of these structural genes will allow the biochemical characterization of the respective gene products. Additionally, genetic differences of grapevine cultivars or species and influences of environmental factors on the stilbene pathway related to the optimization of grapevine stilbene content will be studied. Therefore, this research project will provide new insights into the molecular basis and the regulation of the stilbene pathway in plants, which is still poorly understood. The basic results concerning the genetic differences of grapevine cultivars or species and the impact of environmental factors on stilbene metabolism could allow optimisation of grapevine stilbene content via subsequent grapevine breeding approaches or adaptation of viticultural practices.