Proteome-wide Analysis of lysine 2-hydroxyisobutyrylation shed new light on the carbon metabolism of waterlogged summer maize (Zea mays) leaves

Abstract

Abstract A randomized block experiment with two treatments: control and waterlogging for 6 days at the sixth leaf stage, was conducted to further investigate the mechanism of waterlogging-induced damages on carbon metabolism of summer maize from the aspect of Lysine 2-hydroxyisobutyrylation and proteomic. In this study, waterlogging increased the metabolism of sucrose and starch, promoting the accumulation of carbohydrates in leaves. Additionally, waterlogging increased the lysine 2-hydroxyisobutyrylation of leaves. The correlation of carbohydrate content, photosynthesis, and lysine 2-hydroxyisobutyrylation suggested that lysine 2-hydroxyisobutyrylation may participate in negative feedback of carbohydrate to photosynthesis. Moreover, waterlogging mediated the lysine 2-hydroxyisobutyrylation of proteins participating in modulating the structure and dynamics of thylakoid membrane. Accordingly, the ultrastructure of chloroplast including the grana number (-23.7%), lamellae height (-20.6%) and diameter (+24.1%), were significantly affected by waterlogging. More in detail, the photoreaction centers per unit area (-14.1%) and the transmission light energy per photoreaction center (-9.8%) of waterlogged summer maize were decreased, while the dissipation light energy per photoreaction center was increased (+27.5%) compared with that of CK. These results suggested that lysine 2-hydroxyisobutyrylation was widely involved in regulating the structure and function of chloroplast, thus disturbing plant carbon metabolic process and reducing plant adaptation to the environment.