High nitrogen inhibits biomass and saponins accumulation in a medicinal plant Panax notoginseng

作者：Zhu Cun, Hongmin Wu, Jinyan Zhang, Sheng-Pu Shuang, Jie Hong, Tongxin An, Jun‐Wen Chen · 发表于：PeerJ · 年份：2023 · DOI：10.7717/peerj.14933 · 被引用次数：35 · 研究领域：Plant nutrient uptake and metabolism、Plant Molecular Biology Research、Irrigation Practices and Water Management

Nitrogen (N) is an important macronutrient and is comprehensively involved in the synthesis of secondary metabolites. However, the interaction between N supply and crop yield and the accumulation of effective constituents in an N-sensitive medicinal plant Panax notoginseng (Burkill) F. H. Chen is not completely known. Morphological traits, N use and allocation, photosynthetic capacity and saponins accumulation were evaluated in two- and three-year-old P. notoginseng grown under different N regimes. The number and length of fibrous root, total root length and root volume were reduced with the increase of N supply. The accumulation of leaf and stem biomass (above-ground) were enhanced with increasing N supply, and LN-grown plants had the lowest root biomass. Above-ground biomass was closely correlated with N content, and the relationship between root biomass and N content was negatives in P. notoginseng ( r = −0.92). N use efficiency-related parameters, NUE (N use efficiency, etc .), N C (N content in carboxylation system component) and P n (the net photosynthetic rate) were reduced in HN-grown P. notoginseng . SLN (specific leaf N), Chl (chlorophyll), N L (N content in light capture component) increased with an increase in N application. Interestingly, root biomass was positively correlated with NUE, yield and P n . Above-ground biomass was close negatively correlated with photosynthetic N use efficiency (PNUE). Saponins content was positively correlated with NUE and P n . Add...