外源茉莉酸对小白菜耐硒性及硒积累的作用研究

Study on the Effects of Exogenous Jasmonic Acid on Selenium Tolerance and Selenium Accumulation in Pak Choi(Brassica chinensis L.)

本文研究了不同浓度外源茉莉酸(jasmonic acid,JA,浓度为50μmol/L,100μmol/L)对不同浓度硒酸钠(4mg/kg Se^(6+),10mg/kg Se^(6+))处理下小白菜(Brassica chinensis L.)耐硒性和硒积累量的影响。结果表明,土壤富硒处理显著降低小白菜PSII的光化学反应能力并引起强烈的细胞过氧化反应,显著降低地上部生物量。100μmol/L JA处理显著提高富硒处理土壤小白菜的PSⅡ有效量子产量(F_(v)’/F_(m)’)、电子传递速率(ETR)、光化学猝灭系数(q_(P))、地上部生物量和过氧化氢酶(CAT)活性,并显著降低非光化学猝灭系数(q_(N))和丙二醛(MDA)含量,显著提高富硒处理土壤栽培小白菜的地上部硒含量和硒积累量。50μmol/L JA缓解细胞过氧化和光化学反应抑制效果在4mg/kg Se^(6+)处理下不显著,在10mg/kg Se^(6+)处理下则显著提高最大光化学效率(Fv/F_(m))、F_(v)’/F_(m)’、ETR和CAT活性,但提高幅度小于100μmol/L JA处理。在富硒土壤下,喷施浓度为100μmol/L的外源茉莉酸可提高小白菜的耐硒性和硒积累能力,在促进富硒土壤中作物健康生长和提高作物硒积累能力上具有良好的应用效果。

This study examined the effects of varying exogenous jasmonic acid(JA,50μmol/L,100μmol/L)concentrations on the tolerance and accumulation of selenium(Se)in pak choi cabbage(Brassica chinensis L.)treated with various selenium(Se)concentrations(4mg/kg Se^(6+),10mg/kg Se^(6+)).The results showed that,plants grown in Se-rich soil treatments exhibited Se toxicity,reduced photosynthetic capacity of photosystem(PSII),heavy peroxidization and significant inhibition of shoot biomass.Under Se-rich soil conditions,pak choi cabbage with 100μmol/L JA treatment resisted the effects of Se toxicity.There were significant increases in the effective quantum yield(F_(v)ʹ/F_(m)ʹ),electron transport efficiency(ETR),photochemical quenching coefficient(q_(P)),shoot biomass and catalase(CAT)activity,as well as significant reduced non-photochemical quenching coefficient(q_(N))and malondialdehyde(MDA)content.Additionally,pak choi cabbage cultivated in Se-rich soil and with 100μmol/L JA treatment showed a significant increase in Se content and Se accumulation of shoots.50μmol/L JA treatment produced varying degrees of Se tolerance dependent on the concentration of soil Se.Pak choi cabbage in 4mg/kg Se^(6+)treatment showed reductions in cell peroxidation and inhibition of photochemical reaction,though not significantly.While with 10mg/kg Se^(6+)treatment,there were significant increases in maximum photochemical efficiency(F_(v)/F_(m)),F_(v)ʹ/F_(m)ʹ,ETR,and CAT activity,though not to the degree of the 100μmol/L JA treatment.Application of 100μmol/L exogenous JA on pak choi cabbage can increase Se tolerance and accumulation ability.It is an effective strategy to lessen Se toxicity and enhance crop health in high-Se containing soil.