The Dual Role of Sulfur and Selenium in Mitigating Arsenic Toxicity in Isatis cappadocica Desv.: A Physiological, and Ionomic Analysis of Stress Responses
摘要
In the current study, we manipulated sulfur (S) availability and applied selenium (Se) treatments in order to observe the growth, physiology, and element accumulation of Isatis cappadocica grown under arsenic (As) toxicity. I. cappadocica seedlings were grown in half-strength modified Hoagland solution. At the stage of third fully expanded leaf, S-sufficiency (+ S, 3.4 mmol L−1 sulfate) and S deficiency (-S, 0 mmol L−1sulfate) wereManipulated. At the four-leaf stage, plants were exposed to 0 50, 150, and 450 µM As (V) and 0, 6, and 12 µM Se for 21 days. Plants with adequate S showed double the shoot biomass of those with S deficiency, which also had significantly higher As accumulation (4.12–14.28%) and proline levels (5–45%). Selenium may enhance arsenic phytoremediation in I. cappadocica under S deficiency by increasing biomass by up to 25% and promoting As uptake in S-sufficient conditions. Furthermore, Se improved essential nutrient concentrations (phosphorus, potassium, calcium, iron, and zinc) and reduced As levels by 11.31–28.32% at higher exposures, enhancing growth in As-treated I. cappadocica plants. Our findings indicate that Se does not alleviate S deficiency in the As hyperaccumulator I. capadocica. Conversely, under conditions of sufficient S, Se may enhance arsenic uptake. We advise monitoring S and Se levels in As-contaminated soils, as the strategic supplementation of these elements could significantly influence As accumulation in I. capadocica shoots and aid in the optimization of phytomanagement strategies.