Plant Physiology and Biochemistry 71 (2013) 96e102

Relationship between podophyllotoxin accumulation and soil nutrients and the influence of Fe2þ and Mn2þ on podophyllotoxin biosynthesis in Podophyllum hexandrum tissue culture

Meng Fei Li, Wei Li*, De Long Yang, Lan Lan Zhou, Tian Tian Li, Xiao Meng Su
Gansu Provincial Key Lab of Aridland Crop Science, College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070, PR China

Abstract
Podophyllotoxin (PDT) and its derivatives, which are isolated from the Podophyllum species, are widely used in the clinical setting. The present study was designed to analyze the correlation between PDT levels in the rhizomes of Podophyllum hexandrum (P. hexandrum) and Dysosma versipellis (D. versipellis) and the nutrients in soil. We also aimed to investigate the influence of Fe2þ and Mn2þ on the enzyme activity of phenylalanine ammonia lyase (PAL), cinnamyl alcohol-dehydrogenase (CAD), and deoxypodophyllotoxin 6-hydroylase (DOP6H) and PDT accumulation via P. hexandrum tissue culture. The results showed that PDT accumulation was positively correlated with the NO3 , PO4 3 , Naþ, Fe, and Mn levels and was negatively correlated with the SO4 2 and Kþ levels, while the correlation with the Mg2þ, Ca2þ, Cu and Zn levels was not significant. The Fe2þ and Mn2þ levels were associated with the increased activity of PAL and CAD at 3e18 days; Fe2þ enhanced the activity levels by 2.66- and 1.76-fold, respectively, and Mn2þ was associated with a 1.68- and 1.10-fold increase in activity levels, respectively, compared with the control (CK) at 18 days. DOP6H activity was enhanced by Mn2þ, but it was not significantly affected by Fe2þ. Finally, PDT production was enhanced approximately 60% and 34% by Fe2þ and Mn2þ, respectively, compared with CK at 16 days. These observations may be useful for the generation of PDT and related lignans via commercial cultivation as well as cell and tissue culture of P. hexandrum and other related plant resources.

Keywords: Podophyllotoxin  Podophyllum hexandrum  Soil nutrients  Fe2þ and Mn2þ  Phenylalanine ammonia lyase  Cinnamyl alcohol-dehydrogenase  Deoxypodophyllotoxin 6-hydroylase