Dark-induced senescence provokes profound metabolic shifts to recycle nutrients and to guarantee plant survival. To date, research on these processes has largely focused on characterizing mutants deficient in individual pathways. Here, we adopted a time-resolved genome-wide association-based approach to characterize dark-induced senescence by evaluating the photochemical efficiency and content of primary and lipid metabolites at the beginning, or after 3 or 6 days in darkness. We discovered six patterns of metabolic shifts and identified 215 associations with 81 candidate genes being involved in this process. Among these associations, we validated the roles of four genes associated with glycine, galactinol, threonine, and ornithine levels. We also demonstrated the function of threonine and galactinol catabolism during dark-induced senescence. Intriguingly, we determined that the association between tyrosine contents and TYROSINE AMINOTRANSFERASE 1 influences enzyme activity of the encoded protein and transcriptional activity of the gene under normal and dark conditions, respectively. Moreover, the single-nucleotide polymorphisms affecting the expression of THREONINE ALDOLASE 1 and the amino acid transporter gene AVT1B, respectively, only underlie the variation in threonine and glycine levels in the dark. Taken together, these results allow us to present a very detailed model of the metabolic aspects of dark-induced senescence, as well as the process itself.

中文翻译：

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支持拟南芥暗诱导衰老的代谢变化的全基因组关联

黑暗诱导的衰老引发了深刻的代谢转变，以循环利用养分并保证植物的生存。迄今为止，对这些过程的研究主要集中在表征个体途径缺陷的突变体。在这里，我们采用基于时间分辨的全基因组关联方法来表征黑暗诱导的衰老，方法是在开始时或在黑暗中 3 或 6 天后评估初级和脂质代谢物的光化学效率和含量。我们发现了六种代谢转变模式，并确定了 215 种关联，其中 81 个候选基因参与了这一过程。在这些关联中，我们验证了与甘氨酸、半乳糖醇、苏氨酸和鸟氨酸水平相关的四个基因的作用。我们还展示了暗诱导衰老过程中苏氨酸和半乳糖醇分解代谢的功能。有趣的是，我们确定酪氨酸含量和酪氨酸氨基转移酶 1 之间的关联分别影响编码蛋白质的酶活性和基因在正常和黑暗条件下的转录活性。此外，分别影响苏氨酸醛缩酶 1 和氨基酸转运蛋白基因 AVT1B 表达的单核苷酸多态性仅是黑暗中苏氨酸和甘氨酸水平变化的基础。总之，这些结果使我们能够提出一个非常详细的暗诱导衰老代谢方面的模型，以及过程本身。分别。此外，分别影响苏氨酸醛缩酶 1 和氨基酸转运蛋白基因 AVT1B 表达的单核苷酸多态性仅是黑暗中苏氨酸和甘氨酸水平变化的基础。总之，这些结果使我们能够提出一个非常详细的暗诱导衰老代谢方面的模型，以及过程本身。分别。此外，分别影响苏氨酸醛缩酶 1 和氨基酸转运蛋白基因 AVT1B 表达的单核苷酸多态性仅是黑暗中苏氨酸和甘氨酸水平变化的基础。总之，这些结果使我们能够提出一个非常详细的暗诱导衰老代谢方面的模型，以及过程本身。