外源H2S对干旱胁迫下蓝莓叶片渗透调节及抗氧化能力的影响OA

This study employed three-year-old blueberry'Draper'seedlings as experimental materi-als,and established seven treatment groups:normal watering with distilled water(ck1),moderate drought stress with distilled water application(ck2),and moderate drought stress supplemented with exogenous H2S(NaHS)at five different concentrations of 0.1,0.3,0.5,0.7 and 1.0 mmol/L)(T1-T5).The effects of different concentrations of exogenous H2S(NaHS)on physiological characteristics of blueberry leaves under drought stress were investigated through comprehensive evaluation and corre-lation analysis.Results indicated that,compared with the control,blueberry leaves exhibited signifi-cantly elevated levels of osmotic regulatory substances,antioxidant enzyme activity,and non-enzymatic defence systems.under drought stress.However,aplying exogenous H2S at appropriate concentrations could alleviate drought-induced damage to blueberry.Different concentrations of exog-enous H2S increased soluble sugars(SS)content by 25.42%-54.86%,soluble protein(SP)content by 61.30%-151.67%,and proline(Pro)by 51.84%-162.35%in blueberry under drought stress.Mean-while,these treatments reduced leaf relative electrical conductivity(REC)by 4.79%-32.01%,malo-ndialdehyde(MDA)content by 5.68%-20.59%,and hydrogen peroxide(H2O2)content by 10.42%-28.57%.Furthermore,superoxide anion(O-·2)production rate was reduced by 10.70%-35.04%,super-oxide dismutase(SOD)activity was enhanced by 50.99%-107.89%,and VcSOD gene expression level was upregulated by 3.51-7.15 fold.In conclusion,exogenous H2S can regulate physiological responses in drought-stressed blueberry with a concentration-dependent effect,where the 0.5 mmol/L treatment demonstrated the most pronounced mitigation of drought stress.