Gibberellic acid inhibited chlorophyll degradation in post-harvest okras

Degreening or yellowing caused by rapid chlorophyll (Chl) degradation is a characteristic event during maturation or senescence in green plant organs. In our present study, the effect of gibberellic acid (GA) treatment on Chl content and shelf life in postharvest okras was investigated. Our results indicated that GA treatment could postpone fruit senescence and Chl degradation in okras during storage. Meanwhile, GA treatment also down-regulated the expressions of genes such as AeNYC, AeNOL, AeSGR, AePAO, AeCLH, AeRCCR, AePPH and AeHCAR involved in Chl degradation. Moreover, the down-regulation of transcript abundances of four candidate ERF transcription factors (TFs), preliminarily screened from the okra transcriptome database, was also observed in GA-treated okras. In conclusion, GA had a positive effect on maintaining chlorophyll content and fruit quality of okras after harvest, due to its negative regulation on Chl degradation genes and probably the candidate ERF TFs.