Changes in photosynthesis and antioxidant metabolism of cotton (Gossypium hirsutum L.) plants in response to manganese stress

• Autor(a) principal: Tavanti, Renan Francisco Rimoldi [UNESP]
• Data de Publicação: 2019
• Outros Autores: David Queiroz, Grace [UNESP], Caroline Da Rocha Silva, Anne [UNESP], Moya Peres, Walmor [UNESP], Pereira Paixão, Amanda [UNESP], Galindo, Fernando Shintate [UNESP], Martins Silva, Vinícius [UNESP], Bossolani, João William [UNESP], Moreira Melero, Mariana [UNESP], De Souza Oliveira, Giovane [UNESP], Furlani Júnior, Enes [UNESP], Dos Reis, André Rodrigues [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1080/03650340.2019.1637857; http://hdl.handle.net/11449/190477
• topic: Antioxidant metabolism; Gossypium hirsutumL; hydrogen peroxide; photosynthesis; toxicity

This study aimed to assess the physiological and biochemical responses of cotton plants to manganese (Mn2+) nutrition. Four cotton genotypes (G1–TMG 47; G2–FM 975 WS; G3–TMG 11 WS and G4–IMA 8405 GLT) were grown in nutrient solution under two Mn2+ concentrations (2 and 200 µmol L−1) for 10 days. No visible symptoms of Mn2+ toxicity were observed in the genotypes tested. All genotypes showed a marked increase in leaf chlorophylls, pheophytins, carotenoids, sucrose and total sugars concentration in response to high Mn2+ in a nutrient solution. However, the net photosynthetic rate, stomatal conductance, internal carbon dioxide concentration and transpiration decreased in genotypes G1 and G2 growing under 200 µmol L−1. Antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) activities increased in genotypes G1, G3 and G4. Cotton genotypes showed an increased leaf antioxidant and sugar metabolism as a possible strategy to mitigate oxidative stress. The decrease in the net photosynthetic rate and stomatal conductance; the increased antioxidant enzymes activities (SOD, APX and GR); and the increase in leaf sucrose and total sugar concentration were the main physiological and biochemical responses in cotton plants to Mn2+ stress.