Postharvest commercial technologies are implemented mainly in developed countries to delay excessive softening, extend shelf life and reduce fresh food loss. However, these technologies drive up fresh fruit prices and hence are rarely implemented in developing countries, where they are most needed. The mechanisms of fruit ripening and softening have been elucidated mainly in tomato, with a translational approach, yielding information on fruit softening of several other fruit types. Fruit softening is dependent on cuticle function, cell‐wall integrity, ethylene biosynthesis (in ethylene‐sensitive fruit types) and upstream components that regulate ripening. Despite the cuticle's role, there are as yet no available candidate genes related to cuticle synthesis that can be used to manipulate softening. However, genes encoding enzymes of cell‐wall degradation, ethylene biosynthesis, and upstream transcription factors can serve as candidate genes for shelf‐life extension. This review describes the candidate genes, mainly in tomato, apple, melon, peach, strawberry, and banana, whose manipulation has been shown to delay softening. Although the function of selected candidate genes has been confirmed in these crops, translational research to additional crops requires further analysis. The multiple candidate genes that have already been discovered can be manipulated by genome editing or used in marker‐assistant breeding to extend fleshy fruit shelf life, enabling a reduction in postharvest‐handling costs. Cultivars with extended shelf life are especially suitable for cultivation in developing countries.
Chapter 3
Postharvest commercial technologies are implemented mainly in developed countries to delay excessive softening, extend shelf life and reduce fresh food loss. However, these technologies drive up fresh fruit prices and hence are rarely implemented in developing countries, where they are most needed. The mechanisms of fruit ripening and softening have been elucidated mainly in tomato, with a translational approach, yielding information on fruit softening of several other fruit types. Fruit softening is dependent on cuticle function, cell‐wall integrity, ethylene biosynthesis (in ethylene‐sensitive fruit types) and upstream components that regulate ripening. Despite the cuticle's role, there are as yet no available candidate genes related to cuticle synthesis that can be used to manipulate softening. However, genes encoding enzymes of cell‐wall degradation, ethylene biosynthesis, and upstream transcription factors can serve as candidate genes for shelf‐life extension. This review describes the candidate genes, mainly in tomato, apple, melon, peach, strawberry, and banana, whose manipulation has been shown to delay softening. Although the function of selected candidate genes has been confirmed in these crops, translational research to additional crops requires further analysis. The multiple candidate genes that have already been discovered can be manipulated by genome editing or used in marker‐assistant breeding to extend fleshy fruit shelf life, enabling a reduction in postharvest‐handling costs. Cultivars with extended shelf life are especially suitable for cultivation in developing countries.
Chapter 3