Differential Metabolite Accumulation in Different Tissues of Gleditsia sinensis under Water Stress and Rehydration Conditions

Abstract

Gleditsia sinensis Lam. is a woody species that can tolerate various drought conditions and has been widely used in all aspects of life, including medicine, food, cleaning products, and landscaping. However, few reports have focused on the regulatory mechanism of the drought response in G. sinensis. To understand the metabolic basis of the Gleditsia sinensis drought response, different tissues were subjected to a rehydration/dehydration treatment and subsequently analyzed using untargeted and targeted metabolomics profiling depending on gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass (LC-MS) analytical platforms, respectively. Eight sugars, twelve amino acids, and twenty phenolic compounds were characterized. Metabolites showing a significant increase or decrease under drought stress were considered to be the key metabolites of interest for a better understanding of the drought tolerance mechanisms. The GC-MS-identified compounds were shown to undergo tissue-specific regulation in response to drought stress. Moreover, the C6C3C6 and C6C3 structures were identified by LC-MS as phenolic metabolites, which revealed their drought-response association. Significant physiological parameters were measured, including overall plant development, and the results showed that antioxidant systems could not be completely restored, but photosynthetic parameters could be recovered. The results of this research provide insight into biochemical component information mechanism of drought resistance in G. sinensis.