| Thlaspi arvense L.is a traditional medicinal plant in my country.It has been included in the previous editions of the Pharmacopoeia of the People’s Republic of China.The whole plant of T.arvense can be used as medicine.In recent years,due to human activities,accelerated industrialization and environmental pollution,the ozone layer in the atmosphere has been gradually destroyed,resulting in the continuous increase of UV-B ultraviolet（280-315 nm）radiation reaching the ground environment.In order to understand the growth and influence rules of T.arvense under ultraviolet（UV-B）radiation,it will provide an important basis for the cultivation and utilization of T.arvense.In this paper,the 2-month-old T.arvense was used as the research object,on the basis of natural light,two different radiation intensities of 3.26μW/cm2（T1）and 9.78μW/cm2（T2）were artificially supplemented,as the control group（CK）grown under natural light,the physiological response of T.arvense under supplemental UV-B was studied.On the basis of the above research,the normal growth of T.arvense was sprayed with distilled water as the control group（CK）,the ultraviolet radiation intensity was 9.78μW/cm2,and the distilled water was sprayed as the experimental group 1,the supplementary radiation intensity was 9.78μW/cm2,spraying 0.08g·L-1 exogenous salicylic acid as the experimental group 2,to study the effect of exogenous salicylic acid on T.arvense under the supplementary UV-B radiation.The main results of the study are as follows:（1）The net photosynthetic rate,stomatal conductance,transpiration rate,intercellular CO2concentration,maximum chlorophyll fluorescence parameter（Fm）,PSII primary light energy conversion efficiency（Fv/Fm）and PSII potential photochemistry under two radiation intensities The activity（Fv/F0）decreased with the increase of radiation intensity;the contents of chlorophyll a and chlorophyll b,osmotic regulators,antioxidant enzymes,total phenolics and sinorosin all increased first and then decreased with the increase of radiation time,and the content of total flavonoids showed a gradual upward trend,which was significantly different from the control in the late period of radiation.（2）The stomatal limit value,initial fluorescence and non-photochemical quenching coefficient,auxin,abscisic acid（6～12h）,and salicylic acid（24～60h）of insole under UV-B radiation by spraying the optimum salicylic acid and malondialdehyde（except 48h）,T2 was significantly lower than that of T1 group during the whole treatment process;while the content of chlorophyll b in the whole treatment process（except 12h）,there was no significant difference between T2 and T1 treatment groups;photosynthetic rate,stomata Conductivity,intercellular CO2concentration,transpiration rate,chlorophyll a,Fm,Fv/Fm,Fv/F0,Qp and RET,soluble sugar,free proline（except 12h）,soluble protein（12～60h）,peroxide enzyme（12～60h）,catalase（12～60h）,superoxide dismutase（12～60h）,ascorbic acid peroxidase（6～12h）,total flavonoids（except 48h）,total phenols（except for 60h）,sinoxin（except for 12h）,and gibberellin（except for 60h）were significantly higher than those in the T1 treatment group without salicylic acid treatment.According to the comprehensive analysis of the research results,under a certain UV-B radiation intensity,it can promote the activity of antioxidant enzymes,increase the accumulation of total flavonoids,and increase the content of osmotic adjustment products,and under short-term radiation,it can increase the important factors The content of the secondary metabolite sinigrin in T.arvense,therefore,it can be concluded that the T.arvense has a strong ability to resist UV stress;salicylic acid treatment can reduce the content of T.arvense malondialdehyde and regulate the changes of hormone content,antioxidant enzyme activity,and osmotic regulation product content.and photosynthetic index content to improve the ability of to resist UV stress.This provides a theoretical basis for the cultivation and further utilization of T.arvense stress resistance. |
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