An Analysis of Genetically Engineered Pepper Fruit with Reduced Endo-Beta-1,3- Glucanase (Hemicellulase)

Endo-Beta-1,3-glucanase (hemicellulase) has been proposed to function in the softening of fruit tissue. In pepper fruit, endo-Beta-1,3-glucanase expression is dramatically induced as the fruit ripens, hence we have set out to test the role of this activity in the ripening and senescence of the pepper fruit. Genetically engineered pepper plants with >90% reduction of fruit endo-Beta-1,3-glucanase have been produced. The proposed research is to evaluate whether these hemicellulase-suppressed fruits have altered ripening/senescence properties when compared to normal fruit. Ripening and softening rates will be measured in fruit which are left on or off the vine during and after ripening. The effect of reduced hemicellulase on the post-harvest storage life of pepper fruit will also be measured. In addition to whole tissue measurements of color and softness we will perform cell wall analyses on pericarp extracts from a range of different developmental stages to establish a role for the endo-Beta-1,3-glucanase activity.