Effects of Salicylic Acid on Physiological Responses of Pepper Plants Pre-Subjected to Drought under Rehydration Conditions
Fabrício Custódio de Moura Gonçalves,
Luís Paulo Benetti Mantoan,
Carla Verônica Corrêa,
Nathália de Souza Parreiras,
Luiz Fernando Rolim de Almeida,
Elizabeth Orika Ono,
João Domingos Rodrigues,
Renato de Mello Prado,
Carmen Sílvia Fernandes Boaro
Affiliations
Fabrício Custódio de Moura Gonçalves
Department of Horticulture, Faculty of Agricultural Sciences, São Paulo State University (UNESP), Campus de Botucatu, Avenida Universitária, 3780 Altos do Paraíso, Botucatu 18610-034, Brazil
Luís Paulo Benetti Mantoan
Department of Biodiversity and Biostatistics, Institute of Biosciences, São Paulo State University (UNESP), Campus de Botucatu, R. Prof. Dr. Antônio Celso Wagner Zanin, 250 Distrito de Rubião Junior, Botucatu 18618-689, Brazil
Carla Verônica Corrêa
Department of Horticulture, Faculty of Agricultural Sciences, São Paulo State University (UNESP), Campus de Botucatu, Avenida Universitária, 3780 Altos do Paraíso, Botucatu 18610-034, Brazil
Nathália de Souza Parreiras
Department of Horticulture, Faculty of Agricultural Sciences, São Paulo State University (UNESP), Campus de Botucatu, Avenida Universitária, 3780 Altos do Paraíso, Botucatu 18610-034, Brazil
Luiz Fernando Rolim de Almeida
Department of Biodiversity and Biostatistics, Institute of Biosciences, São Paulo State University (UNESP), Campus de Botucatu, R. Prof. Dr. Antônio Celso Wagner Zanin, 250 Distrito de Rubião Junior, Botucatu 18618-689, Brazil
Elizabeth Orika Ono
Department of Biodiversity and Biostatistics, Institute of Biosciences, São Paulo State University (UNESP), Campus de Botucatu, R. Prof. Dr. Antônio Celso Wagner Zanin, 250 Distrito de Rubião Junior, Botucatu 18618-689, Brazil
João Domingos Rodrigues
Department of Biodiversity and Biostatistics, Institute of Biosciences, São Paulo State University (UNESP), Campus de Botucatu, R. Prof. Dr. Antônio Celso Wagner Zanin, 250 Distrito de Rubião Junior, Botucatu 18618-689, Brazil
Renato de Mello Prado
Department of Soils and Fertilizers, Faculty of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Campus Jaboticabal, Prof. Paulo Donato Castellane s/n, Jaboticabal 14884-900, Brazil
Carmen Sílvia Fernandes Boaro
Department of Biodiversity and Biostatistics, Institute of Biosciences, São Paulo State University (UNESP), Campus de Botucatu, R. Prof. Dr. Antônio Celso Wagner Zanin, 250 Distrito de Rubião Junior, Botucatu 18618-689, Brazil
Capsicum annuum L. has worldwide distribution, but drought has limited its production. There is a lack of research to better understand how this species copes with drought stress, whether it is reversible, and the effects of mitigating agents such as salicylic acid (SA). Therefore, this study aimed to understand the mechanisms of action of SA and rehydration on the physiology of pepper plants grown under drought conditions. The factorial scheme adopted was 3 × 4, with three water regimes (irrigation, drought, and rehydration) and four SA concentrations, namely: 0 (control), 0.5, 1, and 1.5 mM. This study evaluated leaf water percentage, water potential of shoots, chlorophylls (a and b), carotenoids, stomatal conductance, chlorophyll a fluorescence, and hydrogen peroxide (H2O2) concentration at different times of day, water conditions (irrigation, drought, and rehydration), and SA applications (without the addition of a regulator (0) and with the addition of SA at concentrations equal to 0.5, 1, and 1.5 mM). In general, exogenous SA application increased stomatal conductance (gs) responses and modified the fluorescence parameters (ΦPSII, qP, ETR, NPQ, D, and E) of sweet pepper plants subjected to drought followed by rehydration. It was found that the use of SA, especially at concentrations of 1 mM in combination with rehydration, modulates gs, which is reflected in a higher electron transport rate. This, along with the production of photosynthetic pigments, suggests that H2O2 did not cause membrane damage, thereby mitigating the water deficit in pepper plants. Plants under drought conditions and rehydration with foliar SA application at concentrations of 1 mM demonstrated protection against damage resulting from water stress. Focusing on sustainable productivity, foliar SA application of 1 mM could be recommended as a technique to overcome the adverse effects of water stress on pepper plants cultivated in arid and semi-arid regions.
