Rachis degreening is one of the main problems during postharvest storage of grape, its regulatory mechanism remains obscure. Here, we found that production of ethylene was increased and chlorophyll content was decreased during rachis degreening of Shine Muscat grape, while the reverse were observed after 1-MCP (1-methylcyclopropene) treatment. The ethylene transcription factor VvERF95 was isolated, and its transcriptional changes were closely correlated with chlorophyll content during rachis browning. The expression of VvERF95 was induced by ethylene and inhibited by 1-MCP. Dual-luciferase, yeast one-hybrid and EMSA assays, as well as motif mutation experiments, indicated that VvERF95 can bind to the promoter of pheophorbide a oxygenase (VvPAO1) and upregulate its transcript levels. Overexpression of VvERF95 in grape lead to chlorophyll degradation in grape leaves, and increases in the transcript levels of VvPAO1 and most genes in the chlorophyll degradation pathway. Collectively, our findings decipher the mechanism of ethylene-enhanced chlorophyll degradation in grape, and will be useful for manipulating chlorophyll accumulation in grape and other plants.

穗轴脱节是葡萄采后贮藏过程中的主要问题之一，其调控机制尚不清楚。在这里，我们发现在 Shine Muscat 葡萄的穗轴脱色过程中乙烯的产生增加，叶绿素含量降低，而在 1-MCP（1-甲基环丙烯）处理后观察到相反的情况。分离出乙烯转录因子VvERF95，其转录变化与轴褐变过程中的叶绿素含量密切相关。VvERF95的表达受乙烯诱导，受1-MCP抑制。双荧光素酶、酵母单杂交和 EMSA 测定以及基序突变实验表明VvERF95可以与脱镁叶绿素加氧酶的启动子结合( VvPAO1 ) 并上调其转录水平。VvERF95在葡萄中的过表达导致葡萄叶片中的叶绿素降解，并增加了VvPAO1和叶绿素降解途径中大多数基因的转录水平。总的来说，我们的研究结果破译了乙烯增强葡萄叶绿素降解的机制，并将有助于控制葡萄和其他植物中的叶绿素积累。