Elucidating proteolipidome dynamics is crucial for understanding the roles of these molecules in plant physiology and disease. Sequence-based functional annotation of the protein is inadequate, since protein activities depend on posttranslational modification. In this study, we applied a gel-free activity-based protein profiling approach to unravel the active lipases, including other Serine hydrolases (SHs), expressed during seed germination in rice (Oryza sativa). We successfully mapped the active sites of 43 active SHs encompassing lipases/esterases, GDSL lipases, proteases, Ser carboxypeptidases, ABHD protein, pectin acetylesterase, and other SHs. The mRNA expression levels of those genes encoding the identified SHs were monitored using microarray analysis. The lipidome analysis revealed distinct patterns of molecular species distribution in individual lipid classes and displayed the metabolic connections between lipid mobilization and rice seedling growth. Changes in the mobilization of storage lipids and their molecular species remodeling were correlated with the expression of the identified lipases and their lipase activity in a time-dependent manner. The physiological significance of the identified SHs was explored during biotic stress with Fusarium verticillioides infection. The fungal infection significantly reduced lipase activity and lipid mobilization, thus impairing the rice seedling. Collectively, our data demonstrate application of the functional proteome strategy along with the shotgun lipidome approach for the identification of active SHs, and thus for deciphering the role of lipid homeostasis during rice seed germination.

阐明蛋白脂质组动力学对于理解这些分子在植物生理学和疾病中的作用至关重要。基于序列的蛋白质功能注释是不够的，因为蛋白质活性依赖于翻译后修饰。在这项研究中，我们应用基于无凝胶活性的蛋白质分析方法来揭示水稻 (Oryza sativa) 种子萌发过程中表达的活性脂肪酶，包括其他丝氨酸水解酶 (SH )。我们成功绘制了 43 个活性 SH 的活性位点图谱，包括脂肪酶/酯酶、GDSL 脂肪酶、蛋白酶、Ser 羧肽酶、ABHD 蛋白、果胶乙酰酯酶和其他 SH。使用微阵列分析监测编码已识别的SH的基因的mRNA表达水平。脂质组分析揭示了各个脂质类别中分子种类分布的不同模式，并显示了脂质动员与水稻幼苗生长之间的代谢联系。储存脂质的动员及其分子种类重塑的变化与所鉴定的脂肪酶的表达及其脂肪酶活性以时间依赖性方式相关。在轮枝镰刀菌感染的生物胁迫期间，探讨了所鉴定的 SH 的生理意义。真菌感染显着降低脂肪酶活性和脂质动员，从而损害水稻幼苗。总的来说，我们的数据证明了功能蛋白质组策略与鸟枪脂质组方法的应用，用于鉴定活性SH，从而破译水稻种子萌发过程中脂质稳态的作用。