Inhibition of potato tuber sprouting and induction of dry rot resistance during storage in response to 1,4 dimethylnaphthalene and methyl jasmonate

• Ano de defesa: 2021
• Autor(a) principal: Santos, Mirelle Nayana de Sousa
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Batata - Resistência a doenças e pragas; Batata - Perdas pós-colheita - Prevenção; Inibição da brotação; Dormência; Solanum tuberosum; Fisiologia Vegetal
• Link de acesso: https://locus.ufv.br//handle/123456789/28840

Potato is globally the third most important food crop and one of the most consumed foods in the world. The Brazilian production is traded either in natura or processed, which requires long- term storage to keep a continuous on-demand supply. One of the biggest challenges regarding potatoes production system is the complexity in delaying the tuber physico-chemical changes during storage. Alongside, the major factors related to excessive costs into potato production are the significant losses associated with the tuber’s susceptibility to fungal diseases and the intense sprouting incidence after the natural dormancy breakdown. Several techniques have emerged to prolong the interval of potato tubers storage, and this includes the addition of chemicals associated with a cooling system. However, issues related to human toxicology and/or environmental concerns have fostered studies on both non-toxic sprouting inhibitors and plant resistance inducers for tubers. Dimethylnaphthalene (DMN) presents inhibitory properties related to sprouting growth, however, the mechanisms by which DMN underlies other biological effects are unknown. Likewise, Methyl Jasmonate (MeJa) has been considered a sprout inhibitor and a potential resistance inducer. Based on this, the present study investigated the mechanisms induced by DMN and MeJa application underlying both sprouting inhibition and resistance induction to dry rot (Fusarium nirenbergiae) by assessing physiological, physico-chemical, and molecular parameters in stored Asterix and Challenger potato tubers. DMN and MeJA reduced the incidence of sprouting and fresh weight loss, and decreased the effects of reducing sugars on non-enzymatic browning and altered the expression of KRP family cell cycle inhibitor genes in Asterix. However, the treatments did not affect the expression of enzymes related to antioxidant and defense systems in both Asterix and Challenger potato tubers. The efficiency of DMN in delaying dry rot incidence caused by F. nirenbergiae, both in vitro and in vivo, is not related to changes in the activity of antioxidant and defense-related enzymes, which suggests a likely direct action of the compounds on the pathogenicity. Moreover, the results evidence a certain level of resistance in Asterix and Challenger cultivars. Keywords: Solanum tuberosum. Sprout inhibitors. Non-enzymatic browning. Endodormancy. Cell cycle inhibitors. Postharvest diseases. Induced resistance.