Melatonin delays dark-induced leaf senescence by inducing miR171b expression in tomato.
Melatonin delays dark-induced leaf senescence by inducing miR171b expression in tomato.
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褪黑激素通过诱导番茄中 miR171b 的表达来延迟黑暗诱导的叶片衰老。
DOI：
10.1111/jpi.12792
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发表时间：
2022
影响因子：
10.3
通讯作者：
Zhou J
中科院分区：
文献类型：
--
作者：
Wang K;Cai S;Xing Q;Qi Z;Fotopoulos V;Yu J;Zhou J
褪黑素在植物生长、发育和逆境反应的多个方面发挥作用。尽管如此，褪黑素在植物碳代谢中的作用机制在很大程度上仍不清楚。在本研究中，我们研究了褪黑素对番茄叶片淀粉降解的影响。结果表明，外源褪黑素可以缓解碳饥饿诱导的叶绿素降解和叶片衰老。此外，褪黑激素延缓了叶片淀粉的降解，并抑制了日落后淀粉降解酶的转录。有趣的是，当淀粉降解的第一个关键基因α-葡聚糖水二激酶(GWD)过表达时，褪黑素缓解了叶片衰老和淀粉降解的症状。此外，外源褪黑素显著上调了几个microRNAs的转录水平，包括miR171b。重要的是，GWD基因被确定为miR171b的靶标，miR171b的过表达缓解了碳饥饿诱导的叶绿素和淀粉的降解，并抑制了GWD基因的表达。综上所述，这些结果表明褪黑素通过上调miR171b的表达来提高植物对碳饥饿的耐受性，miR171b可以直接抑制番茄叶片中GWD的表达。
Melatonin functions in multiple aspects of plant growth, development, and stress response. Nonetheless, the mechanism of melatonin in plant carbon metabolism remains largely unknown. In this study, we investigated the influence of melatonin on the degradation of starch in tomato leaves. Results showed that exogenous melatonin attenuated carbon starvation‐induced chlorophyll degradation and leaf senescence. In addition, melatonin delayed leaf starch degradation and inhibited the transcription of starch‐degrading enzymes after sunset. Interestingly, melatonin‐alleviated symptoms of leaf senescence and starch degradation were compromised when the first key gene for starch degradation,α‐glucan water dikinase(GWD), was overexpressed. Furthermore, exogenous melatonin significantly upregulated the transcript levels of several microRNAs, includingmiR171b. Crucially, theGWDgene was identified as a target ofmiR171b, and the overexpression ofmiR171bameliorated the carbon starvation‐induced degradation of chlorophyll and starch, and inhibited the expression of theGWDgene. Taken together, these results demonstrate that melatonin promotes plant tolerance against carbon starvation by upregulating the expression ofmiR171b, which can directly inhibitGWDexpression in tomato leaves.