Comparative physiological and transcriptomic analysis reveals an improved biological control efficacy of Sporidiobolus pararoseus Y16 enhanced with ascorbic acid against the oxidative stress tolerance caused by Penicillium expansum in pears.

Sporidiobolus pararoseus Y16, a species of significant ecological importance, has distinctive physiological and biological regulatory systems that aid in its survival and environmental adaptation. The goal of this investigation was to understand the complex interactions between physiological and molecular mechanisms in pear fruits as induced by S. pararoseus Y16. The study investigated the use of S. pararoseus Y16 and ascorbic acid (VC) in combination in controlling blue mold decay in pears via physiological and transcriptomic approach. The study results showed that treatment of S. pararoseus Y16 with 150 μg/mL VC reduced pears blue mold disease incidence from 43% to 11%. Furthermore, the combination of S. pararoseus Y16 and VC significantly inhibited mycelia growth and spore germination of Penicillium expansum in the pear's wounds. The pre-treatment did not impair post-harvest qualities of pear fruit but increased antioxidant enzyme activity specifically polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT) activities as well as phenylalanine ammonia-lyase (PAL) enzyme activity. The transcriptome analysis further uncovered 395 differentially expressed genes (DEGs) and pathways involved in defense mechanisms and disease resistance. Notable pathways of the DEGs include plant-pathogen interaction, tyrosine metabolism, and hormone signal transduction pathways. The integrative approach with both physiological and transcriptomic tools to investigate postharvest pathology in pear fruits with clarification on how S. pararoseus Y16 enhanced with VC, improved gene expression for disease defense, and create alternative controls strategies for managing postharvest diseases.