Present study was performed in order to explicate whether added sulphur (S; 60 mg S kg−1 sand) and calcium (Ca; 250 mg Ca kg−1 sand) alone and in combination could modulate arsenic-induced (As1; 15 mg As kg−1 sand and As2; 30 mg As kg−1 sand) toxicity in Brassica juncea L. seedlings. To study this, growth and growth regulating processes i.e. status of oxidative stress biomarkers (H2O2 generation and lipid peroxidation), enzymes and metabolites of AsA-GSH cycle and S-metabolism were examined. Both the doses of As significantly reduced the growth as evident from diminishing dry weight and increased lipid peroxidation as a consequence of excess H2O2 accumulation. Arsenic also altered the redox status of the cell thereby depleting the AsA and GSH pool that consequently decreased AsA/DHA, AsA/H2O2 and GSH/GSSG ratios. Neverthless, APX, DHAR and GR activities were enhanced under similar conditions. Contrary to this, additional S and/ or Ca maintained the redox status of the cell that improved AsA/DHA and GSH/GSSG ratios, and further enhanced the enzymatic activities in both root and leaves of the test seedlings. Upon As exposure, test seedlings exhibited an increase in S assimilation as a result of increased enzyme activities of ATPS, OASTL and γ-ECS, which were further enhanced upon S and/ or Ca addition to stressed seedlings. Due to increment in S assimilation, PCs synthesis was also increased that restricted As translocation from root to shoot. Collectively, our result provides an insight for protective role of S and Ca alone and more efficiently in combination (S+Ca) to As-stressed Brassica seedlings suggesting that S and Ca together could be a promising candidates in managing As toxicity in crops.

中文翻译：

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硫和钙通过调节抗坏血酸-谷胱甘肽循环和硫代谢减轻芸苔中的砷毒性

目前的研究是为了解释添加的硫（S；60 mg S kg−1 沙）和钙（Ca；250 mg Ca kg−1 沙）单独和组合是否可以调节砷诱导的（As1；15 mg As kg-1 沙和 As2；30 mg As kg-1 沙）在芥菜幼苗中的毒性。为了研究这一点，研究了生长和生长调节过程，即氧化应激生物标志物（H2O2 生成和脂质过氧化）、AsA-GSH 循环和 S-代谢的酶和代谢物的状态。As 的两种剂量都显着降低了生长，这从减少的干重和由于过量 H2O2 积累导致的脂质过氧化增加而明显可见。砷还改变了细胞的氧化还原状态，从而消耗了 AsA 和 GSH 池，从而降低了 AsA/DHA、AsA/H2O2 和 GSH/GSSG 比率。尽管如此，APX，DHAR 和 GR 活性在类似条件下得到增强。与此相反，额外的 S 和/或 Ca 维持细胞的氧化还原状态，提高了 AsA/DHA 和 GSH/GSSG 的比例，并进一步增强了测试幼苗根和叶中的酶活性。暴露于 As 后，由于 ATPS、OASTL 和 γ-ECS 的酶活性增加，测试幼苗表现出 S 同化增加，这些酶活性在向受胁迫的幼苗中添加 S 和/或 Ca 后进一步增强。由于 S 同化的增加，PCs 的合成也增加了，这限制了 As 从根到芽的易位。总的来说，