Transcriptomic Analysis in Response to Combined Stress by UV-B Radiation and Cold in Belle Pepper (Capsicum annuum)

Abstract

The bell pepper (Capsicum annuum L.) is classified as a Solanaceae of economic importance with high nutritional value. However, its production is limited by abiotic factors such as low temperature and UV-B radiation, which can cause extensive damage to crops. Plants may respond to environmental stressors by inducing several morphological, physiological, biochemical and molecular changes. RNA-seq technique is widely applied to study the global gene expression in numerous processes related to plant biology, including responses induced by abiotic stress, providing relevant information about the genes and the pathways that participate in stress-induced responses. In this study, we analyzed the differential gene expression in response to combined stress of UV-B radiation and cold after exposure at 1, 3 and 25 h in stems from C. annuum plants, to gain deeper insights about the temporal dynamic of genes and pathways modulated by these factors. We found that 281, 280 and 326 genes were differentially expressed at 1, 3 and 25 h, respectively. Functional annotation revealed that most of genes were associated with hydrolase activity, stress response, stimulus response, carbohydrate metabolic process, and biosynthetic process. Based on KEGG pathway analysis, we found that circadian rhythm-plant, flavonoids biosynthesis and MAPK signaling pathway were statistically significant in almost all the sampling times. In conclusion, we found that several genes related to defense against pathogens and cell wall expansion were down-regulated, meanwhile the up-regulated genes were related to chloroplast protection, hormone and flavonoids biosynthesis, and compound transport. © 2021 Friends Science Publishers