The Regulation Mechanism of Ethylene and Abscisic Acid on Wheat ( Triticum aestivum L.) Endosperm PCD under Drought Stress Post Anthesis

Drought stress had a great effect on endogenous hormone in wheat, while endogenous hormone profoundly affects the programmed cell death of endosperm and grain filling. The objectives of this study were (i) to investigate the effect of ethylene and abscisic acid on programmed cell death (PCD) in wheat endosperm cells under post-anthesis drought and (ii) to examine the role of ethylene and abscisic acid in regulating grain filling under post-anthesis drought. The wheat plants were spray solvent (CK), cobalt nitrate (CN) and fluoxone (FU), respectively, under drought stress post anthesis. The samples were then compared with respect to cell viability, nuclear morphometry, cell ultrastructure, DNA integrity, DNA content, DNA hydrolase activity, ABA content, ACC content, grain weight and grain filling rate. Analysis was also conducted about gene transcripts related to PCD and ETH receptors. The results showed that under CN treatment, endosperm PCD was delayed, the duration of high grouting rate was prolonged, and the grain weight was increased, in contrast, the opposite result was obtained under FU treatment.