Methyl jasmonate and 1,4-dimethylnaphthalene differentially impact phytohormonal and stress protective pathway regulation involved in potato tuber dormancy

Authors: Dogramaci, Munevver; SARKAR, DIPAYAN - Orise Fellow; DATIR, SAGAR - North Dakota State University; FINGER, FERNANDO - North Dakota State University; SHETTY, KALIDAS - North Dakota State University; Fugate, Karen; Anderson, James

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2024
Publication Date: 4/9/2024
Citation: Dogramaci, M., Sarkar, D., Datir, S., Finger, F., Shetty, K., Fugate, K.K., Anderson, J.V. 2024. Methyl jasmonate and 1,4-dimethylnaphthalene differentially impact phytohormonal and stress protective pathway regulation involved in potato tuber dormancy. Postharvest Biology and Technology. 213. https://doi.org/10.1016/j.postharvbio.2024.112931.
DOI: https://doi.org/10.1016/j.postharvbio.2024.112931

Interpretive Summary: Potato tubers are generally stored for several months after harvest for year-round use. Maintaining higher tuber quality during storage is a primary focus for potato industry. Premature sprouting during long-term storage is one of the major postharvest challenges, which seriously affect tuber quality and marketability. In commercial storage facilities, potato tubers are generally stored at lower temperature and supplemented by sprout inhibitor treatments to prevent premature sprouting. However, there is a significant knowledge gap about how sprout inhibiting chemicals regulate potato tuber sprouting and how they influence the molecular and physiological regulations of potato tubers related to sprout suppression. Therefore, in this study, some promising sprout inhibitor chemicals were applied to tubers of an agronomically significant potato cultivar to understand the impact of these treatments on molecular and physiological mechanisms during storage. Suppression of sprout growth during long-term storage was observed with one of our sprout inhibitor treatments. The same treatment also impacted metabolic regulation associated with major plant hormones and induced plant’s natural defense responses. Overall, this study provides insights on potential impacts of this chemical on molecular and physiological changes associated with sprout suppression of potato tubers at early storage stage.

Technical Abstract: Premature sprouting of potato tubers during storage is a serious postharvest challenge affecting tuber quality and marketability. Finding safe sprout inhibitors to mitigate unintended sprouting related postharvest losses is a prime need of potato industry. Therefore, investigating the impact of promising sprout inhibitor treatments on molecular mechanisms and metabolic pathways that regulate tuber dormancy has wider implications, especially to find biomarkers and identify the mode of action of sprout inhibitors. In this study, Russet Burbank tubers were treated with 1,4-dimethylnaphthalene (DMN) and methyl jasmonate (MeJa) alone or in combination. Sprout growth, changes in dormancy related gene expression, and stress protective pathway regulation was determined at early stages of storage (0-21 days), when meristem tissues are generally endo-dormant. Overall, significant sprout suppression was observed with MeJa and DMN+MeJa treatments. These same sprout inhibitors also resulted in increased abundance of transcripts associated with abscisic acid, brassinosteroids, and dormancy regulation, while transcript abundance of cytokinin and select cell cycle related genes decreased. Although lower metabolic activity related to carbohydrate metabolism was observed in bud meristem tissues, MeJa enhanced stress protective metabolites such as phenolics and antioxidant enzyme activity, indicating a stress inducive mode of action of this sprout inhibitor treatment.