Metabolic Response Of Maize To The Combination Of Drought And Salt Stress

Abiotic stress factors such as drought and salt, seriously affect the growth of plant breeding process. Under the conditions of abiotic stress, plants can reach a new steady state by adjusting metabolic pathways and reorganizing the metabolism network, so study the metabolic mechanisms of stress response in plant is vital. This paper used different maize varieties as the material which were the popular strain in Liaoning province and China in recent years. Based on the1H-NMR, one of the technology platform in metabolomics, this paper mainly studied the response characteristics of the polar and nonpolar extraction metabolites in maize leaves that were treated with drought, salt and the combination with both them. The difference of drought, salt and combined stress with drought and salt in the metabolic mechanism and the regulations in maize biomass, photosynthetic characteristics, the spectral reflectance characteristics and nutrient elements content were also studied.The results showed that the principal component analysis and least squares discriminant analysis can basically distinguish the polar and nonpolar metabolite profiles from salt stress, drought stress and dual stresses to control. Compared with control, analysis of One-Way ANOVA showed that the number of metabolites with significant change were different under different stress conditions. Compared with control, heat map analysis and clustering analysis showed that the profile of polar and nonpolar metabolites in maize subjected to a combination stress of drought and salt changed obviously, and the metabolites profile under salt stress and drought stress are similar. In contrast, there were overlap and specificity in metabolic response of maize to drought stress and salt stress. Clarification of the metabolic pathways and physiological functions based on sugar metabolism, amino acid metabolism, TCA cycle, terpene metabolism and glyceride metabolism suggested that maize under drought and high salt stress showing a new type of response to stress. The combination stresses involved in metabolic cross with two types of single stress. Its characteristics were a decrease in biomass and photosynthetic rate and a complex response mode of metabolism and defense. Also, under different abiotic stresses, the biomass, the photosynthetic characteristics, the spectral reflectance characteristics and the nutrient element content of maize changed in some regular manners.