ABSTRACT The gaseous phytohormone ethylene influences many aspects of plant life, including germination, fruit ripening, senescence, and stress responses. These diverse roles of ethylene occur in part through crosstalk with other phytohormones, which affects ethylene biosynthesis and signaling pathways. We have recently shown that the phytohormones, including gibberellic acid, abscisic acid, auxin, methyl jasmonate, and salicylic acid, regulate the stability of ACC synthases (ACSs), the rate-limiting enzymes in ethylene biosynthesis. Here, we report that treatment of etiolated Arabidopsis seedlings with strigolactone (SL) increases ethylene biosynthesis. SL does not influence ACS stability or ACS gene expression, but it increases the transcript levels of a subset of ACC oxidase (ACO) genes, thereby enhancing ethylene biosynthesis. Taken together with the results of our previous study, these findings demonstrate that most phytohormones differentially regulate ethylene biosynthesis in dark-grown Arabidopsis seedlings by affecting ACS stability and/or the transcript levels of ethylene biosynthesis genes.

中文翻译：

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独脚金内酯提高黄化拟南芥幼苗的乙烯生物合成

摘要 气态植物激素乙烯影响植物生命的许多方面，包括萌发、果实成熟、衰老和应激反应。乙烯的这些不同作用部分是通过与其他植物激素的串扰而发生的，这会影响乙烯的生物合成和信号通路。我们最近表明，植物激素，包括赤霉酸、脱落酸、生长素、茉莉酸甲酯和水杨酸，调节 ACC 合成酶 (ACS) 的稳定性，ACC 合成酶是乙烯生物合成中的限速酶。在这里，我们报告用独脚金内酯 (SL) 处理黄化的拟南芥幼苗增加了乙烯的生物合成。SL 不影响 ACS 稳定性或 ACS 基因表达，但它会增加一部分 ACC 氧化酶 (ACO) 基因的转录水平，从而增强乙烯生物合成。