Chitosan Improving Growth in Chili (Capsicum annuum L.) Plants and Acting Through Distinct Gene Regulation between Cultivars

Abstract

Chili is one of the most cultivated vegetables globally with a wide market potential due to the development in the food and pharmacy industries. A chili cultivation method must comply with good agricultural practices to reduce toxicity from chemical substances. Chitosan is a promising organic alternative to chemical fertilizer and pesticides because its elicitation activity is known to improve growth and resistance in plants. This research documented an improvement in growth parameters in chitosan-treated chili plants such as height increase, number of leaves and chlorophyll content. The regulation of gene expression was also investigated in CM334, C15080, LABA F1 and LADO F1 cultivars treated with chitosan. Seven regulated genes FC >|2| in CM334 and C15080 are involved in protein folding, sugar and protein metabolisms.

These genes were also regulated in LABA F1 and LADO F1 but in different patterns as shown by their relative expression level to a ubiquitin encoding gene. Thus, this study suggests that chitosan improves the growth of chili plants, but the molecular response is distinctive in each cultivar. However, the mode of chitosan-regulated gene expression in all cultivars indicates a correlation to the condition of stress and changes in metabolisms.