Department of Horticulture, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.
Department of Horticulture, Faculty of Agriculture at Kamphaeng Saen Campus, Kasetsart University, Nakhon Pathom 73140, Thailand.
Plant Physiol Biochem. 2018 Apr;125:232-238. doi: 10.1016/j.plaphy.2018.02.004. Epub 2018 Feb 10.
Rapid fruit ripening is a significant problem that limits the shelf life of durian, with ethylene having a major impact on the regulation of this event. Durian treated with ethephon ripened 3 d after treatment with increased pulp total soluble solids, ethylene production of the whole fruit and decreased pulp firmness compared to the control fruit. 1-MCP treatment delayed ripening by up to 9 d with inhibited accumulation of total soluble solids, color change, softening and ethylene production. Genes related to ethylene perception (DzETR1 and DzETR2) and the signaling pathway (DzCTR1, DzEIL1 and DzEIL2) in the pulp were investigated during this process, using qPCR to quantify changes in gene transcription. All candidate genes were significantly up-regulated in ripening durian pulp. Ethephon treatment increased the expression of DzETR1 and DzETR2 genes, while expression of DzCTR1, DzEIL1 and DzEIL2 were slightly affected. 1-MCP treatment significantly inhibited the expression of the DzETR2 and DzEIL1 genes. The promoters of DzETR2 genes were isolated and their activation by fruit transcription factors studied using transient expression in tobacco leaves. It was found that members of the kiwifruit and apple EIL1, EIL2 and EIL3 genes strongly activated the DzETR2 promoter. These results suggest that ethylene-induced ripening of durian is via the regulation of DzETR2 by EIL transcription factors.
果实迅速成熟是限制榴莲货架期的一个重要问题，乙烯在调节这一过程中起着重要作用。与对照果实相比，用乙烯利处理的榴莲在处理后 3 天即可成熟，果肉总可溶性固形物增加，整个果实乙烯生成量增加，果肉硬度降低。1-MCP 处理可将成熟时间延迟 9 天，同时抑制总可溶性固形物的积累、颜色变化、软化和乙烯生成。在这个过程中，使用 qPCR 定量基因转录的变化，研究了 pulp 中与乙烯感知（DzETR1 和 DzETR2）和信号通路（DzCTR1、DzEIL1 和 DzEIL2）相关的基因。所有候选基因在成熟榴莲 pulp 中均显著上调。乙烯利处理增加了 DzETR1 和 DzETR2 基因的表达，而 DzCTR1、DzEIL1 和 DzEIL2 的表达则受到轻微影响。1-MCP 处理显著抑制了 DzETR2 和 DzEIL1 基因的表达。分离了 DzETR2 基因的启动子，并使用烟草叶片中的瞬时表达研究了果实转录因子对其的激活作用。发现猕猴桃和苹果的 EIL1、EIL2 和 EIL3 基因家族成员强烈激活了 DzETR2 启动子。这些结果表明，乙烯诱导榴莲成熟是通过 EIL 转录因子对 DzETR2 的调节来实现的。
