Selenite Foliar Application Alleviates Arsenic Uptake, Accumulation, Migration and Increases Photosynthesis of Different Upland Rice Varieties

Abstract

This study investigates how arsenic (As) uptake, accumulation, and migration responds to selenium (Se) foliar application (0–5.0 mg × kg−1). Rice varieties known to accumulate low (DOURADOAGULHA) and high (SINALOAA68) concentrations of arsenic were chosen to grow on soil with different As concentrations (20.1, 65.2, 83.9 mg × kg−1). The results showed that Se of 1.0 mg × L−1 significantly alleviated As stress on upland rice grown on the As-contaminated soil. Under light (65.2 mg × kg−1) and moderate (83.9 mg × kg−1) As concentration treatments, the biomass of upland rice was increased by 23.15% and 36.46% for DOURADOAGULHA, and 46.3% and 54.9% for SINALOAA68. However, the high Se dose (5.0 mg × kg−1) had no significant effect on biomass and heights of upland rice compared to plants where no Se was added. Se significantly decreased As contents in stems and leaves and had different effects on As transfer coefficients for the two rice varieties: when grown on soil with low and moderate As concentrations, Se could reduce the transfer coefficient from stems to leaves, but when grown on the high As soils, this was not the case. The chlorophyll content in plants grown in soil with the moderate concentration of As could be improved by 27.4%–55.3% compared with no Se treatment. Under different As stress, the Se foliar application increased the net photosynthesis, stomatal conductance, and transpiration rate, which meant that Se could enhance the photosynthesis of rice. The intercellular CO2 concentration variation implied that the stomatal or non-stomatal limitations could both occur for different rice varieties under different Se application doses. In conclusion, under moderate As stress, foliar application of Se (1.0 mg × L−1) is recommend to overcome plant damage and As accumulation.

Selenium Regulates Antioxidant, Photosynthesis, and Cell Permeability in Plants under Various Abiotic Stresses: A Review

“…Se protects chlorophyll and maintains photosynthesis. Drought stress causes water deficiency in plants, closing of leaf stomata, and induction of stomatal conductance [ 52 ], which would further inhibit the supply of CO 2 and reduce the rate of CO 2 assimilation [ 53 ]. Therefore, long-term drought would eventually damage chlorophyll and prohibit photosynthesis in plants [ 50 ].…”

Discovery and Significance of Green and Selenium-Rich of Upland Rice in Xinfeng County, Jiangxi Province,China

“…Meanwhile, the high content of heavy metals will affect the healthy growth of rice; the selenium absorption activity will directly or indirectly affect the growth and development of crops (Xie et al,2021). Scholars from various countries have done more research on the selenium-enrichment and heavy metal content in conventional rice, but do less in the upland rice (Wang et al,2020;Ding et al,2020). In the study, the soil samples and upland rice samples collected from the camellia interplanting upland rice base in Xinfeng County, Jiangxi Province were tested and analyzed for selenium and heavy metal elements.…”