Comprehensive metabolomic and proteomic analysis in biochemical metabolic pathways of rice spikes under drought and submergence stress

Drought and submergence are the main adverse factors affecting plant growth and yield formation in parts of China, especially in the Yangtze River region. In this study, T1 (drought duration: 10 d), T2 (submergence duration: 8 d) and CK (control) treatments were applied. This work aimed to study the changes in metabolic pathways of rice under drought and submergence stress during the panicle differentiation stage. The identification and analysis of differential metabolites and differentially expressed proteins functions indicate that drought and submergence mainly promoted the energy metabolism pathway, carbon fixation in photosynthetic organism pathway, carbohydrate metabolic process, and reactive oxygen species (ROS) metabolic process functions. Under drought stress, the inhibition of photosynthetic rate is mainly through stomatal conductance restriction, and flavonoid pathway regulates the metabolic process of ROS. Under submergence stress, the electron transfer chain was destroyed to inhibit the photosynthetic rate, and the antioxidant system was activated to regulate the metabolism of ROS. The changes in related enzymes or proteins in metabolic regulatory networks are analyzed, which will be conducive to understanding the response mechanism of rice drought and submergence more deeply and provide a scientific basis for rice drought and submergence prevention and mitigation, and the breeding of drought- and submergence-resistant varieties.