Expression of Carotenoid Pathway Genes in Three Capsicum Varieties under Salt Stress

Abstract

Carotenoids pathway is one of decisive anabolic pathway which is responsible for diverse, vital functions such as absorption, dissipation and transfer of solar energy for photosynthesis. Change in environmental factors causes modulation in molecular as well physiological responses to acclimate altered conditions. The current study is designed to assess the difference in the expression pattern of carotenoid pathway genes as well as accumulation of β-carotene among three capsicum varieties having different sensitivity level against salt. To achieve this objective salt tolerant (G4), moderate, tolerant (K2) and sensitive (CO1) varieties were treated under different NaCl concentration (25, 50, 100, 150 and 200 mM) for 30 days. Differential expressions of five major genes of carotenoid pathway (phytoene synthase, phytoene desaturase, zeta carotene desaturase, lycopene β-cyclase and capsanthin/capsorubin synthase) were examined. Semi-quantitative real time PCR expression data have demonstrated the declined expression of genes under study as the salt concentration gradually increased. We also analyzed the impact of salt on chlorophyll content and β-carotene content.