Abstract
We have developed a highly sensitive and high-throughput method for the simultaneous analysis of 43 molecular species of cytokinins, auxins, ABA, and gibberellins (GAs) using an automatic liquid handling system for solid phase extraction, UPLC-ESI-qMS/MS, and chemical derivatization with bromocholine. Our current method needs less than 100 mg (fresh weight) of plant tissues to determine phytohormone profiles and enables us to analyze simultaneously more than 180 plant samples. Application of this method to plant hormone profiling enabled us to draw organ-distribution maps of hormone species in rice and also to identify interactions among the 4 major hormones in the rice GA-signaling mutants, gid1, gid2, and slr. Combining the results of hormone profiling data with transcriptome data in the GA signaling mutants allows us to analyze relationships between changes in gene expression and hormone metabolism. We are now trying to identify key genes regulating hormone levels in rice using QTL analysis. We have measured hormone contents of Sasanishiki X Habataki BILs. The data will be presented.
