西北植物学报2024，Vol.44Issue(4)：551-561,11.DOI:10.7606/j.issn.1000-4025.20230564
外源钙对干旱胁迫下桔梗幼苗生理特性和药用品质的影响
Effects of exogenous calcium on physiological characteristics and medicinal quality of Platycodon grandiflorus seedlings under drought stress
摘要
Abstract
[Objective]Drought stress seriously affects the yield and quality of medicinal plants.This study aims to reveal the physiological mechanism of exogenous calcium in alleviating drought-induced damage in Platycodon grandifloras,which can provide a basis for using exogenous calcium to improve drought re-sistance and medicinal quality of P.grandiflorus in arid and semi-arid area.[Methods]With P.grandi-florus seedlings as materials,a pot experiment was conducted to explore the effects of exogenous calcium on the growth,photosynthetic gas exchange parameters,antioxidant enzyme activity,and medicinal quali-ty of P.grandiflorus seedlings under drought stress by foliar spraying of 10 mmol/L CaCl2.[Results](1)Exogenous calcium significantly increased root length and dry and fresh biomass of P.grandiflorus under drought stress.It significantly increased the stomatal aperture,chlorophyll a content,total chloro-phyll content,carotenoid content,net photosynthetic rate,stomatal conductance,and transpiration rate by 30.28％,57.67％,44.44％,100.33％,89.53％,60.00％,and 83.11％,respectively,in P.grandi-florus leaves under drought stress.(2)Exogenous calcium effectively reduced the content of malondialde-hyde and hydrogen peroxide in P.grandiflorus leaves under drought stress,which was significantly re-duced by 13.82％and 18.66％,respectively,compared to drought stress.Exogenous calcium increased the superoxide dismutase,superoxide dismutase,and catalase activities in P.grandiflorus leaves by 25.43％,7.90％,and 33.92％,respectively,and also increased the soluble protein content in roots com-pared with drought stress.(3)Exogenous calcium significantly increased the levels of latycodin-D,poly-saccharides,total flavonoids,and free amino acids in P.grandiflorus roots by 35.34％,34.87％,4.19％,and 6.52％,respectively,under normal conditions.Under drought stress,the levels were signifi-cantly increased by 10.94％,7.53％,6.07％,and 5.78％,respectively.(4)N,P,K,Ca,Cu,and Mn contents in the aboveground and underground parts of P.grandiflorus were significantly reduced under drought stress,while they were increased to varying degrees under exogenous calcium treatment.[Conclusion]Spraying 10 mmol/L CaCl2 could enhance the antioxidant system activity and osmotic regula-tion ability in P.grandiflorus leaves in arid environment,increase the content of photosynthetic pig-ments and photosynthetic performance,synergistically promote the accumulation of secondary metabolites and mineral elements,improve the quality of medicinal parts,and alleviate the damage of P.grandiflo-rus seedlings under drought stress.关键词
桔梗/干旱胁迫/外源钙/光合作用/次生代谢产物/抗氧化系统Key words
Platycodon grandiflorus/drought stress/exogenous calcium/photosynthesis/secondary me-tabolites/antioxidant systems分类
农业科技引用本文复制引用
苏芸芸,付菲菲,欧晓彬..外源钙对干旱胁迫下桔梗幼苗生理特性和药用品质的影响[J].西北植物学报,2024,44(4):551-561,11.基金项目
甘肃省自然科学基金项目(22JR5RM205) （22JR5RM205）
甘肃省教育科技创新项目(2022B-214) （2022B-214）
庆阳市科技人才专项计划项目(QY-STK-2022A-015) （QY-STK-2022A-015）
博士基金项目(XYBYZK2229) （XYBYZK2229）
