Chemicals and treatments

JA and ibuprofen (IBU) were purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd. They were dissolved in a small amount of ethanol and diluted to the desired concentration with deionized water. Control water received the same amount of ethanol alone, but without JA or IBU. The pH values of all treatment solutions were adjusted to 6.5 with 0.1 M HCl or NaOH.

Panicles having florets nearing anthesis, in which several florets had flowered before the experimental date, were selected for tests. The selected panicles were carefully immersed in 100-ml flasks containing different treatment solutions for 30 s. The effects of the treatments on lodicule volume, lodicule fresh and dry weights, lodicule water content, filament length and potassium and total soluble sugar (TSS) contents were monitored.