增补UV-B辐射对菥蓂生理特性及次生代谢产物的影响

为了解药用植物菥蓂(Thlaspi arvense)在紫外线(UV-B)辐射增强下生长及响应规律，以2月龄菥蓂幼苗为研究对象，在自然光照基础上人工增补3.26μW·cm^-2(T1)和9.78μW·cm^-2(T2)2种不同辐射强度处理，以自然光照下生长的菥蓂幼苗为对照，研究菥蓂幼苗中光合指标和叶绿素荧光参数、光合色素(叶绿素a和b)含量、渗透调节物质(丙二醛、可溶性蛋白、可溶性糖和脯氨酸)含量、抗氧化酶(超氧化物歧化酶、过氧化物酶、过氧化氢酶和抗坏血酸过氧化氢酶)活性和总黄酮、总酚和黑芥子苷等次生代谢产物含量对不同UV-B辐射强度的响应。结果表明：2种辐射强度下净光合速率、气孔导度、蒸腾速率、胞间二氧化碳摩尔分数、最大荧光(F_m)、PSⅡ最大光化学效率(F_v/F_m)和PSⅡ潜在光化学效率(F_v/F_o)均随辐射强度增大而降低；叶绿素a和叶绿素b、可溶性蛋白、可溶性糖和脯氨酸等渗透调节物质、超氧化物歧化酶、过氧化物酶、过氧化氢酶和抗坏血酸过...

Responses of Supplemental UV-B Radiation to Physiological Properties and Secondary Metabolites of Thlaspi arvense

In order to understand the growth rule of the medicinal plant Thlaspi arvense under the enhanced ultraviolet（UV-B） radiation， the 2-months-old seedlings of T. arvense were taken as materials， two different radiation intensities were supplemented artificially with 3.26 μW·cm^-2（T1） and 9.78 μW·cm^-2（T2） on the basis of natural light， and the T. arvense grown under natural light as the control， to investigate the response of various physiological indicators and secondary metabolites to different UV-B radiation intensities， such as photosynthetic indicators and chlorophyll fluorescence parameters， photosynthetic pigments（chlorophyll a and b） content， osmotic adjustment substances（malondialdehyde， soluble protein， soluble sugar and proline） content， activity of antioxidant enzymes（SOD， POD， CAT and APX）， and the content of total flavonoids， total phenols and sinigrin. The results showed： net photosynthetic rate， stomatal conductance， transpiration rate， intercellular CO₂ concentration， maximum fluorescence（F_m）， PSⅡ maximum photochemical efficiency（F_v /F_m） and Potential Photochemical Efficiency of PSⅡ at Two Radiation Intensities（F_v /F₀） and other chlorophyll fluorescence parameters decreased with the increasing of radiation intensity respectively. However， the chlorophyll a and chlorophyll b， osmotic adjustment substances， such as soluble protein， soluble sugar and proline， superoxide dismutase（SOD）， peroxidase（POD）， catalase（CAT） and ascorbate catalase（APX）， total phenols and sinigrin firstly increased and then decreased with the increase of radiation time， while the total flavonoids content gradually increased， which was significantly different（P＜0.05） from the control in the late radiation period. According to the comprehensive analysis of the research results， under different radiation intensities， T. arvense might improve the synthesis of total flavonoids and total phenols， the accumulation of soluble protein and soluble sugar， and the content of chlorophyll， and the activity of superoxide dismutase and peroxidase and catalase increased， to resist the influence of ultraviolet stress， and then showed the resistance and the adaptability to the stress environment of adversity. The results provided a theoretical basis for breeding and further utilization of T. arvense.