Isolation, characterisation, and expression profiling of DXS and DXR genes in Atractylodes lancea.

Abstract

1-Deoxy-d-xylulose-5-phosphate synthase and 1-deoxy-d-xylulose-5-phosphate reductoismerase are considered two key enzymes in the 2-C-methyl-d-erythritol-4-phosphate pathway of terpenoid biosynthesis and are related to the synthesis and accumulation of sesquiterpenoids. We cloned two DXS and DXR genes from Atractylodes lancea and analysed their expression in different tissues and in response to methyl jasmonate (MeJA). Subcellular localisation analysis revealed that the AlDXS and AlDXR1 proteins are located in the chloroplasts and cytoplasm, whereas AlDXR2 is only located in the chloroplasts. pET-AlDXS-28a and pGEX-AlDXR-4T-1 were expressed in Escherichia coli BL21(DE3) and BL21, respectively. Based on the abiotic stress analysis, the growth rate of the recombinant pGEX-AlDXR-4T-1 was higher than that of the control in HCl and NaOH. AlDXS exhibited the highest expression level in rhizomes of A. lancea from Hubei but was highest in leaves from Henan. In contrast, AlDXR showed maximum expression in the leaves of A. lancea from Hubei and Henan. Moreover, DXS and DXR gene expression, enzyme activities, and antioxidant enzyme activities oscillated in response to MeJA, with expression peaks appearing at different time points. Our findings indicated that the characterisation and function of AlDXS and AlDXR could be useful for further elucidating the functions of DXR and DXR genes in A. lancea.