Molecular physiological mechanism on consecutive monoculture problems of Rehmannia glutinosa

DOI: 10.5584/jiomics.v1i2.70

Abstract

Rehmannia glutinosa, a famous Chinese medicinal plant, is not suitable for consecutive monoculture, because there are autotoxic metabolites excreted by its tuberous roots, which can greatly limit the plant growth and development. In this research, cultivar “Wen 85-5” R. glutinosa under three diTerent cultivation modes, including the newly planted, the two-year and three-year consecutively monocultured, was used in the $eld test. +e diTerential expression of leaf proteins, physiological changes and corresponding medicinal quality of tuberous roots at the early tuberous root enlargement stage were detected and compared in diTerent years of consecutive monoculture. +e results showed that consecutive monoculture resulted in decrement of chlorophyll content, photosynthetic capacity and root activity, but increases in free radicals and lipid peroxidation. Furthermore, the content of catalpol, the main medicinal ingredient in R. glutinosa tuberous roots was analyzed by FTIR and HPLC. +e result showed that consecutive monoculture resulted in declined medicinal ingredients. Comparative proteomics analysis revealed 20 diTerentially expressed protein spots in response to increasing years of monoculture. Among them, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) kinase, Rubisco, sedoheptulose-1,7-bisphosphatase related to Calvin cycle, and other proteins, i.e. proteasome, malonyl CoA-ACP transferase, antioxidases, pathogenesis-related protein and mRNA-binding protein were down-regulated with increasing years of monoculture. While energy metabolism related proteins (ATP synthase subunit β, ATPase, ATP-binding protein) and stress response related proteins (heat shock proteins) were up-regulated. +erefore it was concluded that consecutive monoculture of R. glutinosa remarkably aTected the physiological reactions and induced the changes in the expression of leaf proteins, this in turn had a negative impact on the biomass and its quality of the medicinal plants