In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings (Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg⁻¹ of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings. Under compound heavy metal stress, application of 2–4 g L⁻¹ sodium benzoate significantly increased (P>0.01) chlorophyll content and chlorophyll fluorescence parameters F_v/F_m and F_v/F_o of wheat, compared to the control (water treatment). Further analysis showed that application of 2–4 g L⁻¹ sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase (SOD) and reduced malondialdehyde content (MDA). In contrast, higher concentrations of sodium benzoate solution (>6 g L⁻¹) inhibited the growth of wheat seedlings and even caused damage to seedlings. Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97–3.12 g L⁻¹ (2016) and 1.58–3.27 g L⁻¹ (2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest. When the sodium benzoate concentration was raised to 2.59 g L⁻¹ (2016) or 3.02 g L⁻¹ (2017), MDA content was the lowest. Ultimately, exogenous sodium benzoate (2–4 g L⁻¹) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings.

在这项研究中，我们研究了外源苯甲酸钠对重金属胁迫下小麦幼苗（扬麦16号）的影响。结果表明，2.4 mmol kg ^-1的重金属显着抑制小麦幼苗的生长并延迟其出苗。在复合重金属胁迫下，与对照（水）相比，施用2–4 g L ^-1苯甲酸钠显着提高了小麦的叶绿素含量（P > 0.01）和叶绿素荧光参数F _v / F _m和F _v / F _o。治疗）。进一步的分析表明，使用2–4 g L ^-1苯甲酸钠通过促进渗透液（例如可溶性蛋白和游离脯氨酸）的积累来减轻渗透压，增加了超氧化物歧化酶（SOD）的活性并降低了丙二醛含量（MDA）。相反，较高浓度的苯甲酸钠溶液（> 6 g L ^-1）抑制小麦幼苗的生长，甚至对幼苗造成损害。相关分析表明，当苯甲酸钠浓度在1.97-3.12 g L ^-1（2016）和1.58-3.27 g L ^-1（2017）之间时，叶绿素及其成分的值，根活性，SOD活性，可溶性蛋白质和游离脯氨酸含量最高。当苯甲酸钠浓度提高到2.59 g L ^-1（2016）或3.02 g L^-1（2017），MDA含量最低。最终，外源苯甲酸钠（2-4 g L ^-1）促进了根系发育并提高了在复合重金属胁迫下生长的小麦幼苗的根系活性，从而有效减轻了小麦幼苗中复合重金属胁迫的危害。