บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

DFD, a new tomato mutant that prompts a reevaluation of the key determinants of tomato fruit softening and postharvest deterioration.

Saladie M., Watkins C., Labavitch J.M., Shackel K., Rose J.K.C.

5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004. page 5

2004

บทคัดย่อ

DFD, a new tomato mutant that prompts a reevaluation of the key determinants of tomato fruit softening and postharvest deterioration. Fruit softening is a complex physiological event that a major determinant of postharvest fruitquality.Attempts to understand the molecular basis of softening have focused o­n cell wall metabolism and it is now generally believed that fleshy fruits soften as a consequence of polysaccharide degradation in the primary cell wall and middle lamella.Tomato has provided the principal model system for these studies and yet efforts over the last ten years to substantially reduce softening in transgenic tomato lines by suppressing the expression of genes encoding cell wall degrading proteins, such as ploygalacturonase (PG), pectin methylesterase (PME) and expansion, have been largely unsuccessful.

We have recently identified a tomato line, that we named the did (delayed fruit deterioration) mutant, which promises to provide a new perspective of the key molecular determinants of softening and other postharvest quality traits.The two major characteristics of did are substantially reduced fruit softening and completet resistance to postharvest disease, which collectively result in a remarkable shelf life.Unlike other well known ripening-related tomato mutants such as rin (ripening inhibitor) and nor (nom-ripening), dfd fruits undergo essentially noral cliacteric ripening while attached to the plant, with all the organoleptic characteristics and quality properties that are essential for commercialization, such as color, aroma and accumulation of sugars.However, the dfd fruits also maintain a firm texture for a dramatically extended period of time after harvesting and can be stored with no further treatment at room temperature for more than seven months with no signs off deterioration. Moreover, after more than o­ne year, intact and untreated did tomatoes show no signs of microbial infection.

The physiological, molecular and biochemical characterization of the dfd mutant will be presented, together with a new model of the key features that underly tomato fruit softening and tissue disintegration.