外源脯氨酸对盐胁迫下中红麻21号幼苗的缓解效应OA

To investigate the regulatory effects of exogenous proline(Pro)on the growth and physio-logical responses of kenaf seedlings under salt stress,the cultivar'Zhonghongma 21'was used as the ex-perimental material.Kenaf seedlings were subjected to 125 mmol/L NaCl stress and treated with different concentrations of proline(0.05,0.1,0.2,and 0.4 mmol/L)to evaluate their growth performance and physiological characteristics under salt stress.The results showed that exogenous proline significantly alle-viated the growth inhibition caused by salt stress,as evidenced by notable increases in plant height,root length,fresh weight,dry weight,and relative chlorophyll content compared with NaCl treatment alone.In addition,proline application markedly promoted the accumulation of soluble sugars,enhanced the ac-tivities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT),and reduced malond-ialdehyde(MDA)content and relative electrolyte conductivity,thereby effectively mitigating membrane lipid peroxidation.Pro treatment also decreased the accumulation of hydrogen peroxide(H2O2)and su-peroxide anion(O2·-)in leaves,indicating that proline enhances salt tolerance by synergistically regu-lating osmotic adjustment and antioxidant defense systems.Among the tested concentrations,0.2 mmol/L Pro exhibited the most pronounced alleviating effect on salt stress.