Interactive effects of selenium and arsenic on the antioxidant system of Brassica vegetables

QIN Yuyan; CHEN Zhuangmei; WU Feng; LUO Yican; LIU Li; WANG Yunru; LIANG Honghe; HUANG Lingna

doi:10.16861/j.cnki.zggc.2025.0335

Abstract：This study investigated the responses of the antioxidant systems in Brassica vegetables to selenium(Se)and ar-senic(As)stress to reveal the physiological mechanisms underlying their interaction.A soil pot experiment was conducted using choy sum and pak choi as test materials.Treatments included 100 mg·kg-1 As alone,7.5 mg·kg-1 Se alone,and their combined application.Twelve antioxidant parameters in the leaves were measured,and principal component analysis was employed to comprehensively evaluate the antioxidant capacity under different treatments.The results showed that the comprehensive antioxidant capacity of choy sum was higher than that of pak choi.Both individual and combined treat-ments of Se and As caused varying degrees of damage to the antioxidant defense systems of both vegetables.Under As stress with Se supplementation,catalase(CAT)and peroxidase(POD)activity in choy sum leaves decreased significantly,while malondialdehyde(MDA)content increased markedly,indicating enhanced cell membrane damage.In pak choi leaves,the activity of glutathione S-transferase(GST)and ascorbate peroxidase(APX)increased significantly,whereas CAT activity and non-protein thiol(NPTs)content decreased significantly,with no significant change in MDA content.Un-der Se stress with added As,the activy of superoxide dismutase(SOD)and POD in choy sum decreased significantly,whereas CAT,GST,and APX activity in pak choi increased significantly.The antioxidant systems of the two Brassica veg-etables exhibited different response patterns to combined Se and As stress.In choy sum,Se and As showed a synergistic patterns,jointly reducing its antioxidant capacity.In pak choi,they exhibited antagonism in reducing the overall antioxi-dant capacity.Additionally,pak choi primarily relied on enhancing GST and APX activities to cope with Se and As stress.