Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/26/2007
Publication Date: 8/1/2007
Citation: Suttle, J.C. 2007. Involvement of ethylene in chemically induced sprouting. [Abstract.] Potato Association of American 2007 Program & Abstracts. Abstract No 48.
Technical Abstract: At harvest and for an indeterminate period thereafter, tubers are dormant and will not sprout. Dormancy is lost during postharvest storage or after treatment with a variety of unrelated chemicals. The mechanisms of action of these sprout-inducing substances are largely unknown but may involve changes in endogenous hormones. Dormant tubers produce ethylene at very low rates and ethylene production increases as sprouting commences. Further, long-term exposure to ethylene can prematurely terminate dormancy. However, the involvement of ethylene in dormancy termination is unclear. Treatment of dormant Russet Burbank minitubers with zeatin, a synthetic nitro-guanidine cytokinin (NG), gibberellic acid (GA3), or bromoethane (BE) resulted in premature sprouting that was detectable after 7 days and readily observable 14 days after treatment. Increased ethylene production was observed in treated tubers with the greatest and most persistent stimulation occurring in tubers treated with the synthetic cytokinin NG. Pretreatment with the ethylene antagonists silver thiosulfate or 1-methylcyclopropene had no effect on the sprout-inducing activities of NG, GA3, or BE nor did they affect subsequent sprout growth. The ethylene synthesis inhibitor AVG completely suppressed NG-induced ethylene production but had no effect on premature sprouting or subsequent sprout growth. Treatment with exogenous ethylene (0.1 – 10 ppm) for 1, 4 or 7 days did not induce sprouting and application of the ethylene precursor ACC stimulated ethylene production from dormant tubers but did not induce sprouting. Collectively, these results indicate that endogenously produced ethylene does not play a role in chemically induced dormancy termination. (Oral, Physiology, Member # 1977)