Unveiling the influence of methyl jasmonate on key sugar metabolism genes in developing loquat fruit

The evaluation of fruit quality greatly relies on the presence of soluble sugars. In this study, we investigated the dynamics of soluble sugars and basic fruit quality of 'Zaozhong 6' loquat after the application of methyl jasmonate (MeJA). As loquats approached full ripeness, the study unveiled a notable increase in their soluble sugar content, predominantly attributed to the rise in fructose levels. MeJA application accelerated sugar accumulation, suggesting its potential for expediting fruit maturation and enhancing sugar content. Importantly, MeJA-treated fully ripe loquats exhibited a significantly higher sugar-acid ratio. In addition to compositional analyses, the study delves into the molecular aspects of sugar metabolism. Despite the absence of detectable sucrose and glucose, the expressions of FK, HK, SPP, SPS, and SS genes were notably influenced, emphasizing the complex regulatory mechanisms governing sugar metabolism in loquat fruit. This research provides valuable insights into the temporal changes in sugar composition during loquat fruit development, underscores the role of MeJA in shaping these dynamics, and highlights the significance of the sugar-acid ratio in fruit quality determination.