Physiological, biochemical, and ultrastructural characterization of selenium toxicity in cowpea plants

Author(s):Show less -

Silva, Vinicius Martins ^[1] ; Marcandalli Boleta, Eduardo Henrique ^[1] ; Dantas Bereta Lanza, Maria Gabriela ^[2] ; Lavres, Jose ^[3] ; Martins, Juliana Trindade ^[1] ; Santos, Elcio Ferreira ^[3] ; Mendes dos Santos, Flayia Lourenco ^[1] ; Putti, Fernando Ferrari ^[2] ; Furlani Junior, Enes ^[1] ; White, Philip J. ^[4] ; Broadley, Martin R. ^[5] ; Pereira de Carvalho, Hudson Wallace ^[3] ; dos Reis, Andre Rodrigues ^{[1, 2]}

Affiliation

^[1] Sao Paulo State Univ UNESP, BR-15385000 Ilha Solteira, SP - Brazil

^[2] Sao Paulo State Univ UNESP, BR-17602496 Tupa, SP - Brazil

^[3] Univ Sao Paulo, BR-13416000 Piracicaba, SP - Brazil

^[4] James Hutton Inst, Dundee DD2 5DA - Scotland

^[5] Univ Nottingham, Sch Biosci, Loughborough LE12 5RD, Leics - England

• Document type: Journal article
• Source: ENVIRONMENTAL AND EXPERIMENTAL BOTANY; v. 150, p. 172-182, JUN 2018.
• Web of Science Citations: 14

Abstract

Selenium (Se) is considered a beneficial element for plants; however, in high concentrations, it causes negative effects on plant physiology and development. This study reports the first physiological, nutritional, and ultra structural description of Se toxicity in cowpea growing under field conditions. Selenium was supplied as a foliar application of sodium selenite at varying concentrations (0, 50, 100, 200, 400, 800, 1200, and 1600 g ha(-1)). An increased yield was observed with the application of 50 g ha(-1) Se. Application of concentrations higher than 50 g ha(-1) caused leaf toxicity. Increased lipid peroxidation and hydrogen peroxide concentration and reduced total sugars, sucrose, and carotenoid concentration were observed at highest doses tested (1200 and 1600 g ha(-1)). Applications of more than 50 g ha(-1) Se reduced the phloem diameter, caused chlorosis of the leaf blade with a coalescence of lesions, and caused pink salt deposits to appear. Lesions were observed mainly near the trichomes on the adaxial surface of the leaf blade. An analysis of the element distribution with microprobe Xray fluorescence spectrometry (mu-XRF) revealed accumulation of Se, calcium (Ca), potassium (K), copper (Cu), and manganese (Mn) near the primary vein and in the necrotic brown areas of the leaf lesions. In contrast, Na was homogeneously distributed in the leaf tissue. (AU)

• FAPESP's process: 16/19773-8 - Characterization of genotypic variation and agronomic biofortification of cowpea plants with selenium to improve nutritional quality and low phytate content in grains
• Grantee: Vinicius Martins Silva
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 15/19121-8 - Multi-User Equipment approved in grant 2015/05942-0: micro X-Ray Fluorescence system
• Grantee: Hudson Wallace Pereira de Carvalho
• Support Opportunities: Multi-user Equipment Program