Salicylic acid modulates arsenic toxicity by reducing its root to shoot translocation in rice (Oryza sativa L.)

Abstract

Arsenic (As) is posing serious health concerns in South East Asia where rice, an efficient accumulator of As, is prominent crop. Salicylic acid (SA) is an important signaling molecule and plays a crucial role in resistance against biotic and abiotic stress in plants. In present study, ameliorative effect of SA against arsenate (AsV) toxicity has been investigated in rice (Oryza sativa L.). Arsenate stress hampered the plant growth in terms of root, shoots length, and biomass as well as it enhanced the level of H2O2 and MDA in dose dependent manner in shoot. Exogenous application of SA, reverted the growth, and oxidative stress caused by AsV and significantly decreased As translocation to the shoots. Level of As in shoot was positively correlated with the expression of OsLsi2, efflux transporter responsible for root to shoot translocation of As in the form of arsenite (AsIII). SA also overcame AsV induced oxidative stress and modulated the activities of antioxidant enzymes in a differential manner in shoots. As treatment hampered the translocation of Fe in the shoot which was compensated by the SA treatment. The level of Fe in root and shoot was positively correlated with the transcript level of transporters responsible for the accumulation of Fe, OsNRAMP5, and OsFRDL1, in the root and shoot, respectively. Co-application of SA was more effective than pre-treatment for reducing As accumulation as well as imposed toxicity.

Modulation of antioxidant enzymes by salicylic acid in arsenic exposed Glycine max L.

“…While exogenous SA counteracted the As-induced increase in ROS levels (Table 2). Our findings are in line with that of Odjegba (2012) and Singh et al (2015a) in Arabidopsis thaliana and Oryza sativa L. SA mediated lowering in ROS indicates a protective role against As-stress.…”

“…Arsenic-toxicity constitutes one of the major abiotic threats that not only disturb crop production instead human health also. Recent reports revealed that exogenous application of certain chemicals may result in the alleviation of various abiotic stresses that could be important from both theoretical and applied point of views (Namdjoyan and Kermanian, 2013;Singh et al, 2015a). Among such chemicals, SA is recently receiving increasing attention due to its involvement in the plant growth regulation and abiotic stress tolerance mechanism (Dong et al, 2015).…”

“…All these researches demonstrated that SA-regulated abiotic stress tolerance in plants are involved in antioxidant responses, thus suggesting that protection of plants from oxidative damage by SA is intimately linked with an enhanced antioxidant system (Parkhey et al, 2014b). A recent report demonstrated that co-application of SA with As, was more effective in reducing metalloid exerted oxidative injury than its pre-treatment (Singh et al, 2015a).…”

Cellular and signaling mechanisms supporting cadmium tolerance in salicylic acid treated seedlings

“…Additionally, Singh et al (2015) reported that exogenous application of SA reverted the growth, and oxidative stress caused by arsenic V (As V) and significantly decreased As translocation to the shoots. Then, the level of iron (Fe) in root and shoot was completely interrelated with the transcript level of transporters responsible for the accumulation of Fe, OsNRAMP5, and OsFRDL1, in both plant organs.…”

“…Furthermore, Srivastava et al (2014) explained that down regulation of OsLsi2 was owed to minor As concentration in rice shoots in response to thiourea supplementation with As. OsLsi1 is primarily responsible for AsIII transport to root was not related to As uptake in roots (Singh et al, 2015;Armendariz et al, 2016). Otherwise, SA has been revealed to activate ABC transporters in Glycine max (Eichhorn et al, 2006).…”