Selenium application alleviates arsenic-induced toxicity in maize (Zea mays L.)

Arsenic (As) contamination poses a serious threat to crop productivity because of its high toxicity and accumulation in plants. This study investigated the protective effects of selenium (Se) against arsenic-induced toxicity in maize (Zea mays L.). Maize plants were treated with arsenic (150 µM), selenium (25 and 50 µM), and their combination (150 µM As + 25 µM Se). Growth parameters, oxidative stress markers, antioxidant enzyme activities, phenolic compound profiles, and elemental accumulation were evaluated. Arsenic significantly inhibited shoot and root growth, whereas supplementation with 25 µM Se increased shoot and root biomass by 15% and 48%, respectively, compared with arsenic treatment alone. Arsenic stress increased malondialdehyde (MDA) content by 107%, while 25 µM Se reduced this increase by 22%, indicating alleviation of oxidative damage. Selenium supplementation also reduced arsenic accumulation by 24% in shoots and 37% in roots. In addition, chlorogenic acid increased following selenium application, whereas several other phenolic compounds decreased under arsenic stress. Overall, 25 µM selenium mitigated arsenic toxicity by reducing oxidative damage and arsenic accumulation and was associated with improved antioxidant responses and changes in phenolic metabolism, suggesting its potential for alleviating arsenic-induced stress in maize.