Modulation of growth, ascorbate-glutathione cycle and thiol metabolism in rice (Oryza sativa L. cv. MTU-1010) seedlings by arsenic and silicon

Comparative study of silicon and selenium to modulate chloroplast pigments levels, Hill activity, photosynthetic parameters and carbohydrate metabolism under arsenic stress in rice seedlings

“…Si treatment along with As(V), however, promoted the said parameters more than Se supplementation in As(V) treated rice seedlings. Enhanced accumulation of As (see Supplementary Table S2) was the crucial features for the generation of ROS which was, in turn, responsible for enhancement of the oxidative stress markers; this possibly leads to reduced photosynthetic e cacy in As(V) treated rice seedlings as depicted by their less growth and biomass contents in our former studies (Das et al, 2018(Das et al, , 2021. Further, the contents of reducing sugar, non-reducing sugar and total soluble sugar were increased but the starch content was decreased, to maintain osmotic potential in cell cytoplasm under As(V) toxicity in rice seedlings.…”

“…In our previous study, we also reported that in the presence of Si, As accumulation was reduced in rice seedlings (Das et al 2018).…”

“…It has already been noted in the literature that, during As(III) and As(V) accumulation in different rice cultivars, increase in the ROS production as well as de ciency in various enzymatic and non-enzymatic antioxidants activities lead to the generation of oxidative stress Majumder et al, 2018Majumder et al, , 2019. Das et al, (2018) also demonstrated that accumulation of As(V) and As(III) decreased the growth and biomass contents in rice seedlings. In the present study, chlorophyll-a, chlorophyll-b, total chlorophyll contents along with uorescence intensity i.e.…”

“…opening of stomata were getting hampered due to As(V) toxicity, the transpiration rate was also decreased. Therefore, the reduction in chlorophyll-a, chlorophyll-b, chlorophyll a/b ratio, total chlorophyll, carotenoids, Hill activity and all the photosynthetic attributes due to As(V) toxicity might be connected with the less accumulation of carbon that consistently reduced both growth parameters and biomass contents in the test cultivar due to production of ROS under As(V) stress (Das et al, 2018). In plants, ROS production restricted the signaling pathways by weakening the PS-II activity that inhibited less photosynthesis rate by triggering photoinhibition (Gururani et al, 2015).…”

“…Vaculík et al, (2020) reported that Si suppressed the gene expression viz., HMA2, OVP1, NRAMP5, LCT1, that act as transporters for metal uptake so that metal accumulation was reduced in plant cells. Si also reduced total As contents, As(III) contents and oxidative stress markers in rice seedlings under As(V) stress (Das et al, 2018). Etienne et al, (2020) stated that in Brassica napus, Si plays a vital role in the regulation of photosynthetic activities by transcriptomic alterations of DEGs (Differentially Expressed Genes) in shoots by exogenous application of 1.7 mM sodium silicate.…”