The UWA Institute of Agriculture, The University of Western Australia, Perth, 6009, Australia.
The School of Molecular and Chemical Sciences and UWA School of Agriculture and Environment, The University of Western Australia, Perth, 6009, Australia.
Plant Cell Environ. 2018 May;41(5):1154-1170. doi: 10.1111/pce.13141. Epub 2018 Feb 28.
Dormant or quiescent buds of woody perennials are often dense and in the case of grapevine (Vitis vinifera L.) have a low tissue oxygen status. The precise timing of the decision to resume growth is difficult to predict, but once committed, the increase in tissue oxygen status is rapid and developmentally regulated. Here, we show that more than a third of the grapevine homologues of widely conserved hypoxia-responsive genes and nearly a fifth of all grapevine genes possessing a plant hypoxia-responsive promoter element were differentially regulated during bud burst, in apparent harmony with resumption of meristem identity and cell-cycle gene regulation. We then investigated the molecular and biochemical properties of the grapevine ERF-VII homologues, which in other species are oxygen labile and function in transcriptional regulation of hypoxia-responsive genes. Each of the 3 VvERF-VIIs were substrates for oxygen-dependent proteolysis in vitro, as a function of the N-terminal cysteine. Collectively, these data support an important developmental function of oxygen-dependent signalling in determining the timing and effective coordination bud burst in grapevine. In addition, novel regulators, including GASA-, TCP-, MYB3R-, PLT-, and WUS-like transcription factors, were identified as hallmarks of the orderly and functional resumption of growth following quiescence in buds.
木本多年生植物的休眠或静止芽通常密集，而葡萄（Vitis vinifera L.）的组织氧状态较低。重新开始生长的决策的确切时间很难预测，但一旦做出决定，组织氧状态的增加是迅速的，并受发育调控。在这里，我们表明，在芽萌发过程中，葡萄的许多广泛保守的缺氧反应基因的同源物中有超过三分之一，以及所有具有植物缺氧反应启动子元件的基因中有近五分之一被差异调控，这与分生组织身份和细胞周期基因调控的恢复明显一致。然后，我们研究了葡萄 ERF-VII 同源物的分子和生化特性，在其他物种中，这些同源物是对氧敏感的，并且在缺氧反应基因的转录调控中发挥作用。3 个 VvERF-VII 中的每一个在体外都是氧依赖性蛋白水解的底物，作为 N 端半胱氨酸的功能。总的来说，这些数据支持在确定葡萄芽萌发的时间和有效性方面，氧依赖性信号在决定休眠芽萌发的时间和有效性方面的重要发育功能。此外，还鉴定了包括 GASA-、TCP-、MYB3R-、PLT- 和 WUS 样转录因子在内的新型调节剂，作为静止后有序和功能性生长恢复的标志。
