The role of exogenous silicon and salicylic acid applications to increase field pea tolerance to boron toxicity

• Ano de defesa: 2019
• Autor(a) principal: Oliveira, Kevein Ruas de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Pisum sativum (L.); Attenuators; Nutritional disorder; Micronutrient; Oxidative damage; Antioxidant response; Atenuantes; Desordem nutricional; Micronutriente; Dano oxidativo; Resposta antioxidante
• Link de acesso: http://hdl.handle.net/11449/183303

Field peas are widely cultivated throughout the world as a cool season grain and forage crop. By the other way, boron (B) toxicity is caused by high B concentration in soil or irrigation water, and is particularly problematic in medium or heavier textured soil types with moderate alkalinity and low annual rainfall. Previous studies have indicated that B toxicity increases the oxidative stress in plants, and B tolerance has been considered as an important target in field pea plant breeding programmes. In the search for low cost technologies as alternatives to plant breeding, inducers of tolerance may be a promising alternative. Little or none research has been conducted on the combined use of silicon (Si) and salicylic acid (SA) to remediate B toxicity on field peas. The present study revealed the effects of Si+SA on field pea plants physiological and biochemical responses under B toxicity (15 mg B L-1). A semi-hydroponic experiment was conducted under a completely randomized design in a factorial scheme (2 x 5): two field pea cultivars and five treatments which were formed by combining and not Si and SA under B toxicity plus the control plants (control, B, B+Si, B+SA, and B+Si+SA). Si (2 mmol L-1) was applied to plants in two forms (root and leaf), while for SA (36 µmol L-1) only foliar applications were performed. Our results demonstrate that the combined use of exogenous Si+SA in field peas increased tolerance to B toxicity through an intensified antioxidant plant defense system, resulting in a better regulation of reactive oxygen species (ROS) production and degradation. It significantly increased total chlorophyll and carotenoids contents, the activities of major antioxidant enzymes and reduced MDA and H2O2 contents, resulting in increased shoot fresh and total plant dry mass. This alleviated the inhibitory effects of B toxicity in field peas, resulting in greater plant growth by preventing the oxidative membrane damage through an increased tolerance to excess B within plant tissues. Therefore, the use of Si+SA is an important and sustainable strategy to alleviate B toxicity in field pea cultivation.