Simultaneous analysis of endogenous plant growth substances during floral sex differentiation in Jatropha curcas L. using HPLC-ESI-MS/MS

The seed of Jatropha curcas is an ideal feedstock for producing biodiesel. However, low seed yield which was limited by its low female to male flower ratios is a bottleneck for its utilization. Here, six endogenous plant growth substances, Indole-3-acetic acid (IAA), Gibberellin A3 (GA(3)), Zeatin (Zt), Abscisic acid (ABA), Jasmonic acid (JA), and Salicylic acid (SA), were evaluated in male and female floral differentiation stages to uncover the regulatory events of endogenous plant hormones in J. curcas. Our results showed that the female floral initiation was accelerated by the higher concentration of Zt, GA(3), JA, SA and the ratios of JA/GA(3)%, JA/Zt%, and GA(3)/Zt%, whereas its subsequent development was involved in low concentration of Zt and GA(3). Conversely, the lower concentration of Zt, GA(3), JA, SA and the ratios of GA(3)/SA%, Zt/SA%, and JA/SA% were significantly related to male floral initiation, and its subsequent development was co-promoted by the higher concentration of IAA, Zt, GA(3) and JA. In addition, the concentration of ABA was down-regulated both in male and female floral differentiation processes. To our knowledge, this is the first investigation to link floral sex differentiation with endogenous plant growth substances in J. curcas. It provided insight into the potential for the regulation of flowering and the increase of fruit yield with exogenous plant growth substances.