Effects of Tsukamurella tyrosinosolvens P9 on growth,physiology and antioxdant enzyme of peanut under drought stress and after re-watering

Background:The plant-growth-promoting rhizobacterium Tsukamurella tyrosinosolvens is a rare strain of actinomycete,in order to recognize and expand the ecological functions of rare actinomycetes.Methods:In this experiment,we studied the effect of Tsukamurella tyrosinosolvens P9 on the drought resistance of peanut by inoculating peanut seedlings in pots and measuring the growth and physiological indicators of peanut under drought stress and re-watering conditions.Results:The results showed that during drought stress,the relative water content of the soil and leaves,chlorophyll content,and stomatal length,width,and aperture were significantly decreased while the levels of malondialdehyde(MDA),H_(2)O_(2) and stomatal density were significantly increased.Peanut growth was also inhibited.However,inoculation with the P9 strain significantly promoted the growth of peanut under drought stress as plant height,fresh weight,root length and root weight were significantly higher compared with the uninoculated drought stress group.In addition,in P9-inoculated plants,the water and chlorophyll contents were significantly higher and the activities of the antioxidant enzymes CAT and SOD were significantly increased(except during the six days of drought treatment).While the stomatal length,width,and aperture were improved,the levels of MDA and H2O2 were significantly decreased.NBT staining showed that inoculation with P9 reduced O^(2−) accumulation under stress.After re-watering,the physiological indexes of inoculated plants recovered more quickly and grew better.Conclusions:The results showed that T.tyrosinosolvens P9 enhanced drought resistance and improves peanut growth by increasing leaf water content,increasing photosynthesis,regulating stomatal closure,and improving antioxidant enzyme activity.

Facile preparation of nano-g-C_(3)N_(4)/UiO-66-NH_(2) composite as sorbent for high-efficient extraction and preconcentration of food colorants prior to HPLC analysis

In this work,the nano-g-C_(3)N_(4)/Ui O-66-NH_(2)composite was prepared by one-step solvothermal method.The as-prepared composite was characterized by scanning electron microscopy,Brunner-Emmet-Teller measurement,energy dispersive spectrometer,X-ray diffraction,and Fourier transform infrared spectroscopy.By using nano-g-C_(3)N_(4)/Ui O-66-NH_(2)composite as sorbent,a dispersive solid-phase extraction coupled with high-performance liquid chromatography was developed to sensitive analysis of food colorants including tartrazine,amaranth,carmine,sunset yellow,allura red and bright blue.The experiment parameters including the amount of sorbent,adsorption time,the p H of adsorption solution,desorption time,desorption solvent,the p H of desorption solution as well as the proportion between desorption solvent and buffer solvent were investigated.Under the optimized conditions,the limits of detection(S/N=3) and limits of quantitation (S/N=10) were determined in the ranges of 0.08-0.8 and 0.2-2.0 ng/m L,respectively.With the developed sample pretreatment method,carmine and brilliant blue were determined from blueberry juice by HPLC-DAD.The contents were calculated as 1.53μg/m L and0.17μg/mL,respectively.