The Combination of Achnatherum inebrians Extracts and Soil Microorganisms Inhibited Seed Germination and Seedling Growth in Elymus nutans

In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.

Directional screening and identification of potential cytotoxic components from Achnatherum inebrians by a combination of surface palsmon resonance and chromatography

Objective:To establish a method for directional screening of the cytotoxic components from the medicinal herb of Achnatherum inebrians by a combination of surface plasmon resonance(SPR)biosensor and chromatographic isolation technology.Methods:Under the guidance of bioactive assessment based on binding abilities between objects and the a-Mannosidase(a-Man)target,the active components from different solvents extracts,different polar extraction parts and fractions were screened orderly and directionally using SPR.Components with a high binding ability to a-Man can be precisely oriented in a narrower fractions range and are easy to isolate.Three human cancer cells were used to evaluate the cytotoxic activity of component with the highest affinity to a-Man.Results:Eight compounds were isolated and identificated from A.inebrians for the first time.Deoxyvasicinone possessed the highest affinity to a-Man among them.Moreover,deoxyvasicinone showed good effects on inhibited proliferation of human hepatoma cells HepG2(IC_(50)=5.7 μmol/L),human breast cancer cells MCF7(IC_(50)=7.21 μmol/L)and human lung cancer cells HCC827(IC_(50)=0.75 μmol/L),respectively.In particular,its inhibitory effect on HCC827 was stronger than the positive drug gefitinib(IC_(50)=1.65 μmol/L).Conclusion:A comprehensive strategy of directional screening potential cytotoxic components from herb based on biomolecular interaction and chromatography was established.Deoxyvasicinone as an effective anti-cancer component was initially isolated from A.inebrians.It is expected that this screening strategy could provide new perspectives for rapid screening and identification of active components from natural plants with the complex matrix.

The fungal endophyte Epichloëgansuensis increases NaCltolerance in Achnatherum inebrians through enhancing the activity of plasma membrane H^(+)-ATPase and glucose-6-phosphate dehydrogenase

Salt stress negatively affects plant growth,and the fungal endophyte Epichloëgansuensis increases the tolerance of its host grass species,Achnatherum inebrians,to abiotic stresses.In this work,we first evaluated the effects of E.gansuensis on glucose-6-phosphate dehydrogenase(G6PDH)and plasma membrane(PM)H^(+)-ATPase activity of Achnatherum inebrians plants under varying NaCl concentrations.Our results showed that the presence of E.gansuensis increased G6PDH,PMH^(+)-ATPase,superoxide dismutase and catalase activity to decrease O2•^(–),H_(2)O_(2)and Na^(+)contents in A.inebrians under NaCl stress,resulting in enhanced salt tolerance.In addition,the PM NADPH oxidase activity and NADPH/NADP+ratios were all lower in A.inebrians with E.ganusensis plants than A.inebrians plants without this endophyte under NaCl stress.In conclusion,E.gansuensis has a positive role in improving host grass yield under NaCl stress by enhancing the activity of G6PDH and PM H^(+)-ATPase to decrease ROS content.This provides a new way for the selection of stress-resistant and high-quality forage varieties by the use of systemic fungal endophytes.

超声波提取醉马草中生物碱的研究

[目的]研究醉马草中生物碱的超声提取工艺。[方法]采用40 kHz超声波水处理醉马草草粉,水提去渣得到滤液后,分别用氯仿、乙酸乙酯、正丁醇萃取,在回收溶剂的情况下用减压蒸馏获取生物碱,经薄层层析和红外鉴定。[结果]正交试验选取各因素的最佳水平组合为A1B2C2D2,即最佳提取工艺条件为以料液比1∶7.5(g/ml)、温度60℃、超声功率250 W,超声时间60 min;在此条件下生物碱的提取率为2.06 mg/g;新草的生物碱的提取率为14.04 mg/g。结构鉴定结果显示,醉马草混合碱中含有苦马豆素。[结论]该方法快速有效,准确度高,可用于醉马草中生物碱的提取。