บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Delaying senescence in broccoli by genetic modification.

Eason J., Gapper N., Christey M., Coupe S., McDenzie M., Braun R., Watson L., Ryan D., Pinkney T., Brummell D., Heyes J.

5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004, p36.

2004

บทคัดย่อ

Delaying senescence in broccoli by genetic modification.   Broccoli is a highly perishable vegetable recognised for its beneficial contribution to our diet.In practical post-harvest terms, fresh broccoli export to distant markets is achievable provided broccoli is stored at close to 0 °C, in packaging which retains turgor.Nevertheless the subsequent shelf life becomes increasingly short as the storage duration increases.

Our group has been characterising senescence in broccoli for many years and has described details of the processes which accompany senescence (e.g. water loss, ethylene evolution, yellowing, sugar consumption, protein breakdown) and accompanying changes in gene expression.We have now used anti-sense technology to suppress a number of genes whose expression is normally up-regulated during senescence as a means of testing their significance in the progression of broccoli deterioration.These genes were selected from a range of different pathways including protein breakdown, sugar metabolism and ethylene biosynthesis.Some of these genes play useful roles in growing plants so we restricted the expression of the anti-sense genes to the post-harvest period by using the asparagine synthase promoter.In addition we over-expressed a cytokinin biosynthetic gene (iso-pentenyl transferase) using the SAG12 promoter.

Transgenic broccoli lines with delayed leaf senescence were selected and used in a glasshouse trial.Harvested heads were stored at 20 °C and data were collected o colour change and water loss as well as biochemical and molecular data.After four days shelf life some transgenic lines showed delayed senescence but others did not.This multi-target approach tackling genes involved in different pathways has provided fresh insights into the control of post-harvest senescence.