Planting Density Affects Panax notoginseng Growth and Ginsenoside Accumulation by Balancing Primary and Secondary Metabolism

Abstract

Adjusting planting density is a common agricultural practice used to achieve maximum yields. However, whether the quality of medicinal herbs can be improved by implementing appropriate planting densities is still uncertain. The medicinal crop Panax notoginseng was used to analyze the effects of planting density on growth and ginsenoside accumulation, and the possible mechanisms of these effects were revealed through metabonomics. The results showed that P. notoginseng achieved high ginsenoside accumulation at high planting densities (8 × 8 and 10 × 10 cm), while simultaneously achieved high biomass and ginsenoside accumulation at moderate planting density of 15 × 15 cm. At the moderate planting density, the primary metabolism (starch and sucrose metabolism) and secondary metabolism (the biosynthesis of phytohormone IAA and ginsenoside) of the plants were significantly enhanced. However, the strong intraspecific competition at the high planting densities resulted in stress as well as the accumulation of phytohormones (SA and JA), antioxidants (gentiobiose, oxalic acid, dehydroascorbic acid) and other stress resistance-related metabolites. Interestingly, the dry biomass and ginsenoside content were significantly lower at low densities (20 × 20 and 30 × 30 cm) with low intraspecific competition, which disturbed normal carbohydrate metabolism by upregulating galactose metabolism. In summary, an appropriate planting density was benefit for the growth and accumulation of ginsenosides in P. notoginseng by balancing primary metabolism and secondary metabolism.

Physiological responses, yield and medicinal substance (andrographolide, AP1) accumulation of Andrographis paniculata (Burm. f) in response to plant density under controlled environmental conditions

“…A key goal in commercialized plant production is to optimize growth and the biosynthesis of desirable secondary metabolites. However, environmental factors, and agricultural practices can strongly impact theses outcomes [ 53 , 54 ]. Among these, planting density is the most effective factor influencing plant growth and crop quality [ 15 , 55 ].…”

“…Andrographolide (AP1), the major secondary metabolite in Andrographis, has numerous pharmacological effects [ 66 – 68 ]. Findings in Liu [ 54 ] and Verma [ 60 ] found that the synthesis of secondary metabolites in Panax notoginseng and Andrographis paniculata were enhanced when growing at high densities. Although the accumulation of AP1 content in mg g -1 DW -1 is not affected by planting density across developmental stages ( S2 Table ), when AP1 content was expressed as mg DW -1 m -2 , the production of AP1 content was significantly higher at 30 plants per m 2 compared with other planting densities ( Fig 6 ).…”

“…can strongly impact theses outcomes [53,54]. Among these, planting density is the most effective factor influencing plant growth and crop quality [15,55].…”

Comparative analyses of functional traits based on metabolome and economic traits variation of Bletilla striata: Contribution of intercropping

“…All these initial reactions involve synthesizing and degrading amino acids to produce primary metabolites such as carbohydrates, proteins, and lipids (Singh et al, 2020). The primary metabolism provides the necessary energy and precursor substances for the biosynthesis of secondary metabolites in the final step (Liu et al, 2017;Liu et al, 2021).…”

Contributions of Beneficial Microorganisms in Soil Remediation and Quality Improvement of Medicinal Plants

“…The content of active ingredients is considered the key to determining MPs’ clinical efficacy. Among them, secondary metabolites are the main substances with pharmacodynamic functions [ 290 , 291 ]. Chen et al [ 246 ] demonstrated that rhizosphere microbiota was closely related to the contents of oxymatrine, sophoridine and matrine in Sophora flavescens roots.…”