Postharvest quality of ACS down regulated apples.
Hrazdina G., Kiss E., Rosenfield C.L., Galli Z., Hemmat M., Aldwinckle H.S., Norelli J.
5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004, p.64
2004
บทคัดย่อ
Postharvest quality of ACS down regulated apples.
Apples are an important agricultural commodity globally.Most apples are produced for the fresh market, and have to be stored under controlled atmospheric conditions to avoid softening.The softening of fruits is the result of structural changes in the cell walls.These structural changes are caused by the hydrolytic enzymes that are under the control of the ripening hormone ethylene.Ethylene is synthesized in plants from S-adenosyl methionine by tow enzymes: 1-aminocyclopropane –1-carbosylic acid synthase (ACS) and 1-amino-cyclopropane-1-carboxylic acid oxidase (ACO).To interfere with ethylene synthesis in plants we have cloned two ACS genes from ripening apples (McIntosh).The gene showing the closest similarity to ripening – related ACS gene in other fruits was used to make antisense constructs using the CaMV-promoter and kanamycin resistance as selectable marker.Royal Gala and McIntosh plants were transformed with these antisense constructs using a Agrobacterium mediated transformation system.Transgenic plants were propagated on antibiotic-containing agar, transferred to the green house for conditioning and later to the field.Transgenic McIntosh and Royal Gala fruits were evaluated for morphological characteristics, ethylene production, firmness and other ripening parameters.Data indicate a direct relationship between ethylene production and firmness.