Integrated Transcriptomics and Metabolomics Analysis Promotes the Understanding of Adventitious Root Formation in Toxicodendron succedaneum (L.) Kuntze
Toxicodendron succedaneum is an important economic tree species. In the process of establishing a regeneration system for the T. succedaneum, it was found that the axillary buds that are produced from the same tender branch after cutting are inserted into a rooting medium, with a rooting rate of 1%. When the main stem segments of the rooted tissue culture seedlings were placed on the same rooting medium, the rooting rate could reach 100%, and the complete tissue culture seedlings could be obtained. This study is based on the transcriptome and metabolome analysis, combined with the dynamic changes of endogenous hormones, investigates the key molecules, and potential mechanism in the process of adventitious root formation of TSE and TSW in T. succedaneum. The combination of transcriptomics and metabolomics revealed that the differentially expressed genes and differential metabolites in TSE and TSW were significantly enriched in plant hormone signal transduction pathway and alpha-linolenic acid metabolism pathway after 12 hours of cultivation. In the metabolome, the level of jasmonic acid in TSW is significantly lower than in TSE, and the expression levels of key genes in the JA biosynthetic pathway are also significantly lower than those in TSE. Therefore, it can be preliminarily inferred that the reduction in jasmonic acid content in TSW may be an important reason for its rooting. Furthermore, the JA content in TSE was consistently higher than it in TSW at 0,6,12 and 24 hours. Examining the dynamics of hormonal changes, When the jasmonic acid content reaches a certain concentration, it can inhibit the synthesis of auxins, thereby suppressing the formation of adventitious roots. Exogenous application of jasmonic acid and diethofencarb revealed that both high and low concentrations of JA suppress the root growth of T. succedaneum. The impact of diethofencarb treatment on the rooting of T. succedaneum is that high concentrations suppress it while low concentrations promote it. The molecular mechanism of jasmonic acid on AR formation in the T. succedaneum revealed in this study, provides a more comprehensive understanding of the AR formation mechanism in the T. succedaneum and other plants. Overall design: The transcriptome, metabolome, and endogenous hormones of T. succedaneum stems cultured in rooting medium for varying times were measured with the aim to evaluate the differences in adventitious root development of stems with varying rooting abilities. The levels of differentially expressed genes, metabolites, and endogenous phytohormones in the adventitious root development of T. succedaneum were further analyzed within a way explore the differences of lilac in adventitious root development at the physiological, biochemical, and molecular levels and to lay the groundwork for T. succedaneum stem genetic analysis.