Extending bananas shelf life by dsRNA mediated interference of ethylene synthesis

Bananas are highly susceptible to postharvest decay, resulting in reduced edibility. It is widely recognized that ethylene management is crucial for maintaining optimal quality during banana storage and transportation. Recent advances demonstrate significant success of spraying induced gene silencing (SIGS) technology in agricultural practice. Therefore, we hypothesize that SIGS can be explored for banana postharvest quality control. This study investigated the potential of dsRNA mediated SIGS for extending bananas shelf life. The expression of two kinds of rate-limiting enzymes, namely 1-Aminocyclopropane-1-carboxylic acid synthase (ACS) and oxidase (ACO) that involved in ethylene biosynthesis, was quantified by qPCR at first. Then, dsRNAs were designed and synthesized towards the predominant genes. Targeted silencing of MaACS1 and/or MaACO1 by immersion of bananas in dsRNA solutions for 10 min significantly reduced weight loss, maintained firmness and chromatic stability, thereby extending shelf life. Furthermore, preservation efficacy varied significantly among dsRNA constructs of different lengths and those incorporating intron region. Interestingly, ethylene evolution in fruits treated by dsMaACO1 incorporated with intron region (dsMaACO1-I) were the most significantly reduced, due to efficient silencing of the target gene transcription and subsequent translation. At last, fluorescence tracing of Cy5-dsRNA confirmed cellular internalization from the surface of banana to inner peel but without distribution in parenchyma tissues. In conclusion, the study indicates dsRNA-mediated SIGS can be used for banana postharvest quality control, and this novel technology might be applicable for extending shelf life of other fresh fruit and vegetables.