Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China.
School of Landscape Architecture School of Tourism and Health, Zhejiang A & F University, Zhejiang, 311300, Hangzhou, China.
BMC Plant Biol. 2021 Nov 3;21(1):512. doi: 10.1186/s12870-021-03286-x.
Senescence represents the last stage of flower development. Phosphorylation is the key posttranslational modification that regulates protein functions, and kinases may be more required than phosphatases during plant growth and development. However, little is known about global phosphorylation changes during flower senescence.
In this work, we quantitatively investigated the petunia phosphoproteome following ethylene or air treatment. In total, 2170 phosphosites in 1184 protein groups were identified, among which 2059 sites in 1124 proteins were quantified. To our surprise, treatment with ethylene resulted in 697 downregulated and only 117 upregulated phosphosites using a 1.5-fold threshold (FDR < 0.05), which showed that ethylene negatively regulates global phosphorylation levels and that phosphorylation of many proteins was not necessary during flower senescence. Phosphoproteome analysis showed that ethylene regulates ethylene and ABA signalling transduction pathways via phosphorylation levels. One of the major targets of ethylene-induced dephosphorylation is the plant mRNA splicing machinery, and ethylene treatment increases the number of alternative splicing events of precursor RNAs in petunia corollas.
Protein dephosphorylation could play an important role in ethylene-induced senescence, and ethylene treatment increased the number of AS precursor RNAs in petunia corollas.
衰老代表着花发育的最后阶段。磷酸化是调节蛋白质功能的关键翻译后修饰，在植物生长发育过程中，激酶的作用可能比磷酸酶更为重要。然而，人们对花衰老过程中的整体磷酸化变化知之甚少。
在这项工作中，我们定量研究了乙烯或空气处理后矮牵牛的磷酸化组。总共鉴定了 1184 个蛋白组中的 2170 个磷酸化位点，其中 1124 个蛋白中的 2059 个位点被定量。令我们惊讶的是，使用 1.5 倍阈值（FDR<0.05），乙烯处理导致 697 个下调和仅 117 个上调的磷酸化位点，这表明乙烯负调控整体磷酸化水平，并且花衰老过程中许多蛋白质的磷酸化并非必需。磷酸化组分析表明，乙烯通过磷酸化水平调节乙烯和 ABA 信号转导途径。乙烯诱导去磷酸化的主要靶标之一是植物 mRNA 剪接机制，乙烯处理增加了矮牵牛花瓣中前体 RNA 的可变剪接事件的数量。
蛋白质去磷酸化可能在乙烯诱导的衰老中起重要作用，乙烯处理增加了矮牵牛花瓣中 AS 前体 RNA 的数量。
