Fruit Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Suwon, 440-706, Republic of Korea.
J Plant Res. 2014 Mar;127(2):359-71. doi: 10.1007/s10265-013-0623-x. Epub 2013 Dec 28.
The concept that gibberellin (GA) application on seeded grapevines induces seedlessness has been known for decades in viticulture. GA was applied to inflorescence clusters of seeded diploid grapevine cultivar 'Tamnara' (Vitis spp.) at 14 days before full bloom (DBF). Morphological and molecular effects of GA application were examined on the induction of parthenocarpic fruit development. With GA application, ovaries were enlarged and pollen tube growth was completely inhibited. Vitis GA oxidase enzymes, key determinants for GA level, were characterized through phylogenetic analysis with Arabidopsis GA oxidase enzymes. Five VvGA 20-oxidase (VvGA20ox), three VvGA 3-oxidase (VvGA3ox), and nine VvGA 2-oxidase (VvGA2ox) family proteins, and one VvGA methyltransferase (VvGAMT) and one Vitis cytochrome P450 714A1 proteins were identified, and their expression patterns were analyzed during inflorescence development from 14 DBF to 5 days after full bloom (DAF). VvGA2ox1, VvGA20ox3, and VvGA3ox2 were the most abundantly expressed genes in each gene family at 7, 5, and 2 DBF, respectively. Following GA application at 14 DBF inducing seedlessness, GA catabolic genes such as VvGAMT2, VvGA2ox3, and VvGA2ox4 were up-regulated at 12 DBF, full bloom, and 5 DAF, respectively. Conversely, most GA biosynthetic genes, VvGA20oxs and VvGA3oxs, were down-regulated at near full bloom, and the timing of their peak expression was changed. These results suggest that GA application at pre-bloom changes the GA biosynthesis into GA catabolic pathway at near full bloom by altering the transcription level and timing of GA oxidase genes during grapevine inflorescence development.
几十年来，在葡萄栽培学中，人们已经知道赤霉素（GA）在有核葡萄藤上的应用会导致无核。GA 于完全开花前 14 天（DBF）应用于二倍体葡萄品种“Tamnara”（Vitis spp.）的花序簇。研究了 GA 应用对诱导单性结实果实发育的形态和分子影响。用 GA 处理后，子房增大，花粉管生长完全受到抑制。通过与拟南芥 GA 氧化酶的系统发育分析，对葡萄 GA 氧化酶酶，关键的 GA 水平决定因素进行了特征描述。鉴定了 5 个 VvGA20-氧化酶（VvGA20ox）、3 个 VvGA3-氧化酶（VvGA3ox）和 9 个 VvGA2-氧化酶（VvGA2ox）家族蛋白，以及 1 个 VvGA 甲基转移酶（VvGAMT）和 1 个 Vitis 细胞色素 P450 714A1 蛋白，并分析了它们在花序发育过程中的表达模式从 14 DBF 到完全开花后 5 天（DAF）。在每个基因家族中，VvGA2ox1、VvGA20ox3 和 VvGA3ox2 在 7、5 和 2 DBF 时的表达量最高。在 14 DBF 时应用 GA 诱导无核后，GA 分解代谢基因如 VvGAMT2、VvGA2ox3 和 VvGA2ox4 分别在 12 DBF、完全开花和 5 DAF 上调。相反，大多数 GA 生物合成基因，VvGA20oxs 和 VvGA3oxs，在近完全开花时下调，并且它们的表达峰值时间发生了变化。这些结果表明，GA 在开花前的应用通过改变葡萄花序发育过程中 GA 氧化酶基因的转录水平和时间，将 GA 生物合成转变为 GA 分解代谢途径。
