Dipartimento di Scienze Agrarie e Ambientali, University of Udine, Via delle Scienze 208, 33100 Udine, Italy.
J Exp Bot. 2011 Aug;62(12):4345-54. doi: 10.1093/jxb/err150. Epub 2011 May 16.
This study reports the first observations indicating the spatiotemporal relationships among genetic and physiological aspects of ripening in the berry of Vitis vinifera. At the onset of ripening in the red flesh variety Alicante Bouschet, colour development began in the flesh at the stylar end of the fruit and progressed toward the pedicel end flesh and into the skin. Tissue solute potential and cell turgor also decreased first in the flesh. The decrease in flesh solute potential was due to accumulation of sugars, glucose and fructose, an accumulation that is integral to ripening. Expression of the anthocyanin biosynthesis-related genes VvMybA and VvUFGT was linearly related to the decrease in solute potential. Expression of VvMybA, and to a lesser extent VvUFGT, was correspondingly low in green tissue, higher in the red, stylar end flesh of berries beginning to ripen, and greatest in red berries. In contrast, expression of the abscisic acid biosynthesis-related genes VvNCED1 and VvNCED2 was not correlated with the other spatiotemporal aspects of the onset of ripening. These results, together with earlier work showing that sugar accumulation and acid loss also begin in the stylar flesh in other varieties, indicate that ripening in the grape berry originates in the stylar end flesh.
本研究首次观察到葡萄浆果成熟过程中遗传和生理方面的时空关系。在红色果肉品种 Alicante Bouschet 成熟开始时，颜色首先在果实的花柱端果肉中形成，并向果柄端果肉和果皮中发展。组织溶质势和细胞膨压也首先在果肉中下降。果肉溶质势的下降是由于糖、葡萄糖和果糖的积累，这种积累是成熟的一个组成部分。与花色苷生物合成相关的基因 VvMybA 和 VvUFGT 的表达与溶质势的下降呈线性相关。VvMybA 的表达，在一定程度上 VvUFGT 的表达，在绿色组织中较低，在开始成熟的浆果红色、花柱端果肉中较高，在红色浆果中最高。相比之下，与脱落酸生物合成相关的基因 VvNCED1 和 VvNCED2 的表达与成熟开始的其他时空方面没有相关性。这些结果与早期的工作表明，在其他品种中，糖的积累和酸的损失也开始于花柱果肉，表明葡萄浆果的成熟始于花柱端果肉。
