Metabolomics and Hormone Level Analysis of Seashore paspalum Dwarf Mutant T51

Abstract

The use of slow-growing Seashore paspalum dwarf varieties is an effective way to reduce mowing frequency. Here, the differences in metabolism and hormone levels between Seashore paspalum dwarf mutant T51 and WT were investigated. Finally, the genes associated with the dwarf phenotype were screened in combination with our previous studies. At the metabolic level, 236 differential metabolites were identified. Further screening of hormone-related differential metabolites found that ABA and SA of T51 were increased significantly, while IAA and its intermediate metabolite indolepyruvate of T51 were decreased significantly. Endogenous hormone content assay showed that there was no difference in GA and BR content between T51 and WT; However, the IAA content of T51 was significantly reduced compared with WT. The results of exogenous hormone treatment showed that the sensitivity of T51 to exogenous hormones was IAA > GA > BR. TAA1, YUCCA, and NIT were down-regulated at both the transcriptional and protein levels; CYP79B2 and CYP79B3 were down-regulated at the protein level but had no difference at the transcriptional level. In conclusion, we propose that the down-regulated expression of TAA1, YUCCA, NIT, CYP79B2, and CYP79B3 leads to the decrease of IAA content, which is one of the important reasons for the dwarf phenotype of T51; TAA1, YUCCA, and NIT are important candidate genes related to T51 dwarf.