Beijing Key Laboratory for Agricultural Application and New Technique, College of Plant Science and Technology, Beijing University of Agriculture, Beijing, China.
Beijing Key Laboratory for Agricultural Application and New Technique, College of Plant Science and Technology, Beijing University of Agriculture, Beijing, China.
Mol Cell Proteomics. 2023 Jun;22(6):100549. doi: 10.1016/j.mcpro.2023.100549. Epub 2023 Apr 18.
Plant vacuoles serve as the primary intracellular compartments for inorganic phosphate (Pi) storage. Passage of Pi across vacuolar membranes plays a critical role in buffering the cytoplasmic Pi level against fluctuations of external Pi and metabolic activities. To gain new insights into the proteins and processes, vacuolar Pi level regulated by vacuolar phosphate transporter 1 (VPT1) in Arabidopsis, we carried out tandem mass tag labeling proteome and phosphoproteome profiling of Arabidopsis WT and vpt1 loss-of-function mutant plants. The vpt1 mutant had a marked reduced vacuolar Pi level and a slight increased cytosol Pi level. The mutant was stunted as reflected in the reduction of the fresh weight compared with WT plants and bolting earlier under normal growth conditions in soil. Over 5566 proteins and 7965 phosphopeptides were quantified. About 146 and 83 proteins were significantly changed at protein abundance or site-specific phosphorylation levels, but only six proteins were shared between them. Functional enrichment analysis revealed that the changes of Pi states in vpt1 are associated with photosynthesis, translation, RNA splicing, and defense response, consistent with similar studies in Arabidopsis. Except for PAP26, EIN2, and KIN10, which were reported to be associated with phosphate starvation signal, we also found that many differential proteins involved in abscisic acid signaling, such as CARK1, SnRK1, and AREB3, were significantly changed in vpt1. Our study illuminates several new aspects of the phosphate response and identifies important targets for further investigation and potential crop improvement.
植物液泡是无机磷（Pi）储存的主要细胞内隔室。Pi 通过液泡膜的转运在缓冲细胞质 Pi 水平对外部 Pi 和代谢活动的波动方面起着关键作用。为了深入了解蛋白质和过程，我们对拟南芥中的液泡 Pi 水平进行了串联质量标签标记蛋白质组学和磷酸化蛋白质组学分析，该水平受液泡磷酸盐转运蛋白 1（VPT1）的调控。vpt1 突变体的液泡 Pi 水平明显降低，细胞质 Pi 水平略有升高。与 WT 植物相比，突变体生长受阻，表现在鲜重减少，在正常土壤生长条件下抽薹更早。定量了超过 5566 种蛋白质和 7965 种磷酸肽。约有 146 种和 83 种蛋白质在蛋白质丰度或位点特异性磷酸化水平上发生显著变化，但它们之间只有 6 种蛋白质是共有的。功能富集分析表明，vpt1 中 Pi 状态的变化与光合作用、翻译、RNA 剪接和防御反应有关，与拟南芥的类似研究一致。除了 PAP26、EIN2 和 KIN10 与磷酸盐饥饿信号有关外，我们还发现许多参与脱落酸信号的差异蛋白，如 CARK1、SnRK1 和 AREB3，在 vpt1 中也发生了显著变化。我们的研究阐明了磷酸盐反应的几个新方面，并确定了进一步研究和潜在作物改良的重要目标。
