Castellarin Simone D, Pfeiffer Antonella, Sivilotti Paolo, Degan Mirko, Peterlunger Enrico, DI Gaspero Gabriele
Dipartimento di Scienze Agrarie e Ambientali, University of Udine, via delle Scienze 208, 33100 Udine, Italy.
Plant Cell Environ. 2007 Nov;30(11):1381-99. doi: 10.1111/j.1365-3040.2007.01716.x.
Anthocyanin biosynthesis is strongly up-regulated in ripening fruit of grapevines (Vitis vinifera L.) grown under drought conditions. We investigated the effects of long-term water deficit on the expression of genes coding for flavonoid and anthocyanin biosynthetic enzymes and related transcription factors, genes sensitive to endogenous [sugars, abscisic acid (ABA)] and environmental (light) stimuli connected to drought stress, and genes developmentally regulated in ripening berries. Total anthocyanin content has increased at harvest in water-stressed (WS) fruits by 37-57% in two consecutive years. At least 84% of the total variation in anthocyanin content was explained by the linear relationship between the integral of mRNA accumulation of the specific anthocyanin biosynthetic gene UDP-glucose : flavonoid 3-O-glucosyltransferase (UFGT) and metabolite content during time series from véraison through ripening. Chalcone synthase (CHS2, CHS3) and flavanone 3-hydroxylase (F3H) genes of the flavonoid pathway showed high correlation as well. Genes coding for flavonoid 3',5'-hydroxylase (F3'5'H) and O-methyltransferase (OMT) were also up-regulated in berries from dehydrated plants in which anthocyanin composition enriched in more hydroxylated and more methoxylated derivatives such as malvidin and peonidin, the grape anthocyanins to which human gastric bilitranslocase displays the highest affinity. The induction in WS plants of structural and regulatory genes of the flavonoid pathway and of genes that trigger brassinosteroid hormonal onset of maturation suggested that the interrelationships between developmental and environmental signalling pathways were magnified by water deficit which actively promoted fruit maturation and, in this context, anthocyanin biosynthesis.
在干旱条件下生长的葡萄（Vitis vinifera L.）成熟果实中，花青素生物合成被强烈上调。我们研究了长期水分亏缺对编码类黄酮和花青素生物合成酶及相关转录因子的基因表达的影响，这些基因对内源[糖、脱落酸（ABA）]和与干旱胁迫相关的环境（光）刺激敏感，以及在成熟浆果中受发育调控的基因。连续两年，水分胁迫（WS）果实收获时总花青素含量增加了37 - 57%。在从转色期到成熟的时间序列中，特定花青素生物合成基因UDP - 葡萄糖：类黄酮3 - O - 葡糖基转移酶（UFGT）的mRNA积累积分与代谢物含量之间的线性关系解释了至少84%的花青素含量总变化。类黄酮途径的查尔酮合酶（CHS2、CHS3）和黄烷酮3 - 羟化酶（F3H）基因也显示出高度相关性。编码类黄酮3'，5' - 羟化酶（F3'5'H）和O - 甲基转移酶（OMT）的基因在脱水植物的浆果中也被上调，其中花青素组成富含更多羟基化和更多甲氧基化衍生物，如锦葵色素和芍药色素，人类胃胆色素转运蛋白对这些葡萄花青素具有最高亲和力。水分胁迫植物中类黄酮途径的结构和调控基因以及触发油菜素内酯激素成熟起始的基因的诱导表明，发育和环境信号通路之间的相互关系因水分亏缺而放大，水分亏缺积极促进果实成熟，并在此背景下促进花青素生物合成。
