Differential gene expression analysis under salinity stress in the selected turmeric ( Curcuma longa L.) cultivars for curcuminoid biosynthesis

Background Curcuminoids are the phenolic compounds found exclusively in turmeric. Their presence is known to increase immunity and resistance against certain cancers and neurological disorders in humans also, protecting the plant itself against salinity stress. Methods In this experiment, we studied the expression levels of MAPK1 and DCS genes, their curcuminoid biosynthesis under salinity stress conditions so that the impact of individual genes can be understood using semi- quantitative PCR. Results The expressions of the genes with respect to curcuminoid biosynthesis showed fluctuations in their band intensity values due to the production of curcuminoids, which is initiated first in the leaves followed by the rhizomes. Not all the genes responsible for the curcuminoid biosynthesis show positive regulation under salt stress conditions which is observed in response to the severity of the stress imposed on the cultivars. Conclusions In our findings, both the genes MAPK1 and DCS were down-regulated for curcuminoid biosynthesis compared to their controls in both the cultivars Vallabh Sharad and Selection 1.