Combined supplementation of selenium and silica boosts growth and yield of rice (Oryza sativa L.) by stimulating photosynthetic efficiency and nutrient uptake.

Rice, a staple food for more than half of the global population, is often exposed to arsenic (As) which disrupt the photosynthetic efficiency and reduce growth and yield. However, selenium (Se) and silica (Si) supplementation counteract it. In this study, simulated pot experiments were conducted to evaluate the effects of different species and doses of Se [i.e. selenite (SeIV) and selenate (SeVI); 0.5 and 1 mg l-1] and Si (0.4%), on growth, yield, photosynthesis and nutrient elements composition of rice under As (1 mg l-1) exposure. Correlation analysis revealed that As significantly reduced uptake of nutrient elements from soil, which subsequently reduced their accumulation in leaves, specially those are involved in chlorophyll synthesis i.e. magnesium (Mg; r = - 0.820), potassium (K; r = - 0.737) and nitrogen (N; r = - 0.253), which resulted into reduced level of total chlorophyll (T.Chl.; r = - 0.314) and thereby reduced photosynthetic rate (Pn; r = - 0.507). Further, its exposure decreased the Chl. of PSII reaction centre (Chl.a dimer), resulting in ~ 31% decrease in photochemical quenching (qP) and ~ 18% increase in non-photochemical quenching (NPQ) reactions. However, supplementation of Se, specially, SeIV (1 mg l-1) + Si (0.4%), boosted the growth and yield by counteracting these losses. In addition, Se (1 mg l-1) + Si (0.4%) supplementation significantly enhanced the T.Chl. (59%), Pn (56%), stomatal conductance (gs; 118%) and qP (78%), while reduced NPQ (15%) than As exposed rice plants. Correlation analysis also revealed that increased N level in leaves of Se + Si supplemented plants significantly increased qP (r = 0.793) and subsequently Pn rate (r = 0.697). Hence, the supplementation of SeIV (1 mg l⁻1) and Si (0.4%) significantly reduced As levels in rice grains (~ ten fold), and enhancing plant growth, yield, nutrient uptake, and photosynthesis. Therefore, these elements appear beneficial for fertilization in paddy fields of As affected areas. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-025-01592-4.