College of Enology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
College of Enology, Northwest A&F University, Yangling, 712100, Shaanxi, China; Shaanxi Engineering Research Center for Viti-Viniculture, Yangling, Shaanxi, 712100, China.
Plant Physiol Biochem. 2021 Oct;167:1072-1082. doi: 10.1016/j.plaphy.2021.09.022. Epub 2021 Sep 20.
Leaf removal (LR) around the cluster zone is a common practice for regulating grape quality. The purpose of this study was to assess the effects of cluster-zone leaf removal, applied at the pea-size stage of berry development, on berry soluble sugar, organic acid and phenolic compound, sugar unloading-related gene expression of Vitis. vinifera L. Syrah. Four different severities of leaf removal were applied: no leaf removal (Control), removing 2 leaves above the cluster (LR1), removing 4 leaves above the cluster (LR2), and removing 6 leaves above the cluster (LR3). The three leaf removal treatments (LR), especially removing 4 leaves (LR2), resulted in significantly higher reducing sugar, soluble sugar (glucose, fructose and sucrose), total anthocyanin and citric acid contents as compared to the control group during ripening for both vintages. At harvest, the LR treatments increased the transcript abundance of most sugar unloading-related genes. In addition, VvHT3, VvHT5, VvSUC11, VvSUC12, VvSS and VvcwINV were positively correlated with both reducing sugar contents and soluble sugar contents. Our results suggest that removing 4 leaves above the cluster is useful for improving the quality of Syrah (Vitis vinifera L.) grapes in cool climate regions with excessive leaves. These findings provide insights into the molecular basis of the relationship between leaf removing and hexose (glucose and fructose) accumulation in the grape berries.
叶幕区去叶是调控葡萄品质的常用措施。本研究旨在评估在浆果豌豆粒大小期（pea-size stage of berry development）实施果穗周围叶幕区去叶（cluster-zone leaf removal）对酿酒葡萄品种希拉（Vitis. vinifera L. Syrah）浆果可溶糖、有机酸和酚类化合物以及糖卸载相关基因表达的影响。共实施了 4 种不同的去叶严重度处理：无去叶（对照，Control）、去除果穗上方 2 片叶（LR1）、去除果穗上方 4 片叶（LR2）和去除果穗上方 6 片叶（LR3）。与对照相比，两个年份的成熟过程中，LR 处理（尤其是去除 4 片叶，LR2）均显著提高了还原糖、可溶糖（葡萄糖、果糖和蔗糖）、总花色苷和柠檬酸含量。收获时，LR 处理增加了大多数糖卸载相关基因的转录丰度。此外，VvHT3、VvHT5、VvSUC11、VvSUC12、VvSS 和 VvcwINV 与还原糖含量和可溶糖含量均呈正相关。这些结果表明，在气候凉爽、叶片过多的地区，去除果穗上方 4 片叶有利于提高希拉葡萄的品质。这些发现为叶幕区去叶与葡萄浆果中己糖（葡萄糖和果糖）积累之间的关系提供了分子基础的见解。
