Perpustakaan Digital ITB

Bananas, including plantains, are vital fruit crops in tropical and subtropical regions, providing essential nutrition, employment, and income, thus supporting the economy, food security, and poverty alleviation. Indonesia ranks as the sixth largest banana producer globally. However, bananas ripen quickly, leading to rapid quality decline. Chitosan, a non-toxic, biodegradable, and biocompatible substance, shows promise in delaying banana ripening, although its application is labor-intensive. Genetic approaches to postharvest losses can reduce costs and energy inputs while enhancing food security, particularly for bananas (Musa acuminata). Epigenetics, particularly DNA methylation, plays a crucial role in fruit ripening. Yet, the molecular mechanisms behind banana ripening require further exploration to improve postharvest management strategies. This study focuses on how chitosan affects DNA methylation dynamics during banana ripening. Both chitosan and DNA methylation influence the expression of genes involved in the ripening process. The study specifically examined the effect of 1.25% chitosan on global DNA methylation in bananas, targeting the promoter regions of the MaMADS1 (EU869307) and MaMADS2 (EU869306) genes. Results indicated an increase in global DNA methylation from 56.2% to 63.3% by day 3 in chitosan-treated bananas, although this decreased to 46.7% compared to green bananas at day 0. Increased global DNA methylation generally slows the ripening process in climacteric fruits by regulating key genes related to ethylene production, cell wall modification, pigment synthesis, and other ripening pathways. Promoter-specific methylation analysis using methylation-specific PCR (MS-PCR) revealed that CpG islands 1 and 3 of MaMADS1 and MaMADS2 were consistently unmethylated across all ripening stages in control bananas. However, CpG island 2 showed variable methylation patterns, indicating a repressive role of MaMADS1 and MaMADS2 during banana ripening. These findings suggest that targeting specific DNA methylation sites can be used to delay ripening, improve quality control, and enhance postharvest handling of bananas.