The present study was designed to see the influence of selenium (Se) and sulphur (S) in the alleviation of arsenic (As)-induced stress in Brassica juncea plant. Se-induced alterations in physiological and biochemical responses due to deficient S (DS), normal S (NS) and additional S (AS) conditions were evaluated in 14-day-old seedlings of B. juncea variety Varuna. During the last 7 days of the 14-day-old seedlings, supplementation with arsenite (AsIII, 300 μM) alone and its combination with selenite (SeIV, 50 μM) along with different S treatments was done which are as follows: (i) control; (ii) As; (iii) As+Se+DS; (iv) As+Se + NS; (v) As+Se + AS. Experimental results showed that the application of AS in spite of NS supplied with Se influenced plant growth, oxidative stress and thiol-ascorbate-related parameters more prominently under As stress. The plants with As+Se+AS treatment exhibited lower ROS (superoxide and hydrogen peroxide ion), malondialdehyde (MDA) accumulation and lipoxygenase activity with increased activities of superoxide dismutase, catalase and ascorbate peroxidase compared with As+Se+NS condition. These plants also exhibited an increase in cysteine, non-protein thiols and phytochelatins, along with reduced, oxidised and redox content of glutathione and ascorbate. Furthermore, the application of S along with Se increased the activities of glutathione reductase, glutathione S-transferase, glutathione peroxidase, monodehydroascorbate and dehydroascorbate to minimise As stress. However, we observed that these responses were reversed under As+Se+DS condition and induced oxidative stress, which was almost similar to As only treatment. It indicated that AS nutrition potentiated Se to alleviate As-inhibited plant growth by modulating antioxidants including thiol-ascorbate-based mechanism and reducing As accumulation in B. juncea plants.

中文翻译：

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硫通过调节芥菜中的氧化应激，积累和硫醇-抗坏血酸代谢来增强硒，从而减轻砷诱导的应激。

本研究旨在观察硒和硫对减轻芥菜油菜中砷诱导的胁迫的影响。在芥菜芽孢杆菌变种Varuna的14日龄幼苗中，评估了硒引起的生理和生化反应的变化，这是由于缺乏的S（DS），正常的S（NS）和其他的S（AS）条件引起的。在14天大的幼苗的最后7天中，单独添加了亚砷酸盐（AsIII，300μM）以及与亚硒酸盐（SeIV，50μM）的组合以及不同的S处理，如下所示：（i）控制; （ii）作为；（iii）As + Se + DS；（iv）As + Se + NS；（v）As + Se + AS。实验结果表明，在硒胁迫下，尽管施用了硒，但施用硫磺会显着影响植物的生长，氧化胁迫和硫醇抗坏血酸相关的参数。与As + Se + NS处理相比，经As + Se + AS处理的植物表现出较低的ROS（超氧化物和过氧化氢离子），丙二醛（MDA）积累和脂氧合酶活性，并且超氧化物歧化酶，过氧化氢酶和抗坏血酸过氧化物酶的活性增加。这些植物还表现出半胱氨酸，非蛋白质硫醇和植物螯合素的增加，同时谷胱甘肽和抗坏血酸的含量减少，氧化和氧化还原。此外，与硒一起施用硫可增加谷胱甘肽还原酶，谷胱甘肽S-转移酶，谷胱甘肽过氧化物酶，单脱氢抗坏血酸和脱氢抗坏血酸的活性，从而最大程度地降低砷胁迫。然而，我们观察到这些反应在As + Se + DS条件下逆转并诱导了氧化应激，这与仅As处理几乎相似。