Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2013
Publication Date: 1/6/2014
Citation: Suttle, J.C., Olson, L.L. 2014. Role of gibberellins in 1,8-Cineole mediated sprout inhibition [abstract.] American Journal of Potato Research. 91(1):68.
Technical Abstract: At harvest and for an indeterminate period thereafter, potato tubers are dormant and will not sprout. Tuber dormancy is lost during postharvest storage and the subsequent sprouting results in the loss of tuber processing and nutritional qualities. Therefore, control of tuber sprouting is an essential aspect of successful long-term potato storage. Oxygenated mono-terpenes are principal components of many plant essential oils and exhibit both anti-microbial and plant growth inhibiting properties. A survey of plant-derived mono-terpenes by Vaughn and Spencer (1991) identified 1,8-cineole as a potent inhibitor of potato sprout growth. To date, its mechanism of action as a sprout inhibitor remains unknown. Tuber sprout growth was inhibited by 1,8-cineole in a dose-dependent manner. Comparative studies demonstrated that vapor-phase concentrations of 1,8-cineole which inhibited tuber sprout growth by >50% also inhibited etiolated seedling hypocotyl elongation but had no effects on potato callus proliferation or etiolated seedling root growth. These results were not consistent with a direct effect of 1,8-cineole on cell division or elongation but rather an indirect effect reminiscent of hormonal perturbation. LC-MS analysis of endogenous hormone contents in sprouts isolated from cineole-treated tubers revealed a significant increase in total ABA metabolites and decline in GA content. Application of GA20 and GA1 reversed cineole-mediated inhibition of tuber sprout growth while GA19 did not. As determined by qRT-PCR, transcript abundances of key GA metabolic genes in sprouts were significantly affected by cineole treatment. Collectively, these results suggest that inhibition of bioactive GA synthesis plays a role in 1,8-cineole mediated sprout growth inhibition.