Nitric oxide alleviates selenium toxicity in rice by regulating antioxidation, selenium uptake, speciation and gene expression. (February 2020)

• Record Type: Journal Article
• Authors: Dai, Zhihua; Rizwan, Muhammad; Gao, Fei; Yuan, Yuan; Huang, Hengliang; Hossain, Md Muzammel; Xiong, Shuanglian; Cao, Menghua; Liu, Yongxian; Tu, Shuxin
• Is Part Of: Environmental pollution. Volume 257(2020)
• Publication Date: 2020-02
• Subjects: Nitric oxide -- Rice -- Gene expression -- Selenium toxicity -- Selenium speciation -- Photosynthesis; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113540
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: In plants, excess selenium (Se) causes toxicity, while the beneficial effects of nitric oxide (NO) have verified in plants under various abiotic conditions. In order to ensure safely Se-enriched rice production, the objective of the research was to clarify how exogenous NO alleviated high Se toxicity in rice. Under high Se (25 μM) stress, the effects of exogenous NO (by applying sodium nitroprusside, an exogenous NO donor) on growth parameters, Se content, Se speciation, photosynthesis, antioxidant system, expressions of Se transport and metabolism-related genes (phosphate transporter, OsPT2 ; S-adenosylmethionine synthase 1, OsSAMS1 ; cysteine synthase, OsCS; Se-binding protein gene, OsSBP1 ) in rice seedlings were investigated by a hydroponic experiment. The results showed that exogenous NO alleviated high Se-induced irreversible damage to root morphology, growth, photosynthesis, antioxidant capacity and decreased the contents of MDA, H2 O2 and proline significantly in rice seedlings. Compared with high Se treatment, application of exogenous NO reduced root Se content (10%), and the Se(VI) decreased by 100% in root and shoot. Besides, exogenous NO decreased the accumulation of inorganic Se speciation in rice roots and shoots. Also, the qRT-PCR analysis showed that down-regulated gene expressions of OsPT2, OsSAMS1 and OsCS affected significantly via exogenous NO. So, the exogenous NO could effectively decrease the toxicity of high Se treatment in rice. Graphical abstract: Image 1 Highlights: NO promoted the antioxidant capacity of rice seedlings. SNP alleviated the toxicity of high Se treatment in rice seedlings. SNP decreased the inorganic Se in rice roots and shoots. High selenium up-regulated the expressions of OsPT2 and OsSAMS1. The SNP down-regulated the expressions of OsPT2, OsSAMS1 and OsSBP1 genes in roots of rice seedlings.