Targeted disruption of a cell wall-modifying gene α-Mannosidase using CRISPR-Cas9 enhances post-harvest shelf life in tomato through ABA accumulation

Tomato ripening is a complex process regulated by transcription factors, hormones, and physiological changes. While this intricate regulation ensures desirable traits such as color, texture, and flavor, it is often accompanied by rapid post-harvest deterioration and poor shelf life, leading to significant economic losses and limiting market potential. Various cell wall-modifying enzymes, including N-glycan-processing enzyme α-Mannosidase, play crucial roles in the softening and senescence of tomato fruits. Our study shows that α-Mannosidase knockout through CRISPR/Cas9 results in fruits with enhanced firmness, longer shelf life, and improved moisture retention. Additionally, the expression of SlRIN (Ripening Inhibitor), a key regulator of ripening and several downstream genes, including those involved in cell wall degradation, ethylene biosynthesis, and signaling, was downregulated. Interestingly, in the later stages of storage, they also exhibited higher accumulation of abscisic acid (ABA) and lower accumulation of reactive oxygen species, along with better antioxidant capacity, compared to the control fruits, which may confer delayed softening and increased shelf life. Our findings highlight α-Mannosidase as a ripening-specific regulator and a promising genetic target for extending tomato shelf life, offering a sustainable strategy to minimize post-harvest losses without compromising plant development.