Ubiquitination, an essential post-transcriptional modification (PTM), plays a vital role in nearly every biological process, including development and growth. Despite its functions in plant reproductive development, its targets in rice panicles remain unclear. In this study, we used proteome-wide profiling of lysine ubiquitination in rice (O. sativa ssp. indica) young panicles. We created the largest ubiquitinome dataset in rice to date, identifying 1638 lysine ubiquitination sites on 916 unique proteins. We detected three conserved ubiquitination motifs, noting that acidic glutamic acid (E) and aspartic acid (D) were most frequently present around ubiquitinated lysine. Enrichment analysis of Gene Ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of these ubiquitinated proteins revealed that ubiquitination plays an important role in fundamental cellular processes in rice young panicles. Interestingly, enrichment analysis of protein domains indicated that ubiquitination was enriched on a variety of receptor-like kinases and cytoplasmic tyrosine and serine-threonine kinases. Furthermore, we analyzed the crosstalk between ubiquitination, acetylation, and succinylation, and constructed a potential protein interaction network within our rice ubiquitinome. Moreover, we identified ubiquitinated proteins related to pollen and grain development, indicating that ubiquitination may play a critical role in the physiological functions in young panicles. Taken together, we reported the most comprehensive lysine ubiquitinome in rice so far, and used it to reveal the functional role of lysine ubiquitination in rice young panicles.

泛素化是必不可少的转录后修饰（PTM），在几乎每个生物过程（包括发育和生长）中都起着至关重要的作用。尽管其在植物生殖发育中具有功能，但其在水稻穗中的目标仍不清楚。在这项研究中，我们使用全蛋白质组的剖析赖氨酸泛素在水稻（栽培稻亚种籼稻）幼穗。我们创建了迄今为止水稻中最大的泛素基因组数据集，确定了1638个赖氨酸泛素化916个独特蛋白质上的位点。我们检测到三个保守的泛素化基序，并注意到酸性谷氨酸（E）和天冬氨酸（D）最普遍存在于泛素化赖氨酸周围。这些泛素化蛋白的基因本体论（GO）注释和《京都议定书》的基因与基因组百科全书（KEGG）途径的富集分析表明，泛素化在水稻幼穗的基本细胞过程中起着重要作用。有趣的是，蛋白质结构域的富集分析表明泛素化富集于多种受体样激酶，胞质酪氨酸和丝氨酸-苏氨酸激酶上。此外，我们分析了泛素化，乙酰化和琥珀酰化之间的串扰，并在我们体内构建了潜在的蛋白质相互作用网络。水稻泛素组。此外，我们确定了与花粉和谷物发育相关的泛素化蛋白，表明泛素化可能在幼穗的生理功能中起关键作用。总之，我们报道了最全面的赖氨酸ubiquitinome在大米，到目前为止，并用它来揭示的功能作用赖氨酸泛素在水稻幼穗。