Foliar application of proline on the mitigation of salt stress in the physiological indices of sour passion fruit

• Autor(a) principal: Santos, Larissa Fernanda Souza
• Data de Publicação: 2023
• Outros Autores: Lima, Geovani Soares de, Lima, Vera Lucia Antunes de, Silva, André Alisson Rodrigues da, Soares , Lauriane Almeida dos Anjos, Nóbrega, Jackson Silva, Capitulino, Jessica Dayanne, o Borborema, Lucyelly Dâmela Araúj, Souza, Allesson Ramos de, Caetano, Edmilson Júnio Medeiros
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/49013
• topic: Passiflora edulis Sims; Salinidade; Passiflora edulis Sims; Salinity; Osmolyte synthesis.

Salinity is one of the main abiotic stresses that significantly constrict plant growth and lead to substantial reductions in crop yield. The adverse effects of salt stress are particularly pronounced in semi-arid regions, due to unfavorable climatic conditions and the presence of high-salinity water sources. In this context, the exploration of strategies for utilizing saline water in irrigation is essential to address the global food production demand. Therefore, the objective of this study was to assess the impact of foliar application of proline concentrations on the physiological indices of sour passion fruit during the seedling formation phase, with saline water as the irrigation source. The research was carried out within a greenhouse belonging to the Agricultural Engineering Academic Unit of the Federal University of Campina Grande, situated in Campina Grande – PB, Brazil. The study employed a completely randomized experimental design, organized in a 5 × 4 factorial arrangement consisting of five levels of electrical conductivity in the irrigation water (ECw: 0.6, 1.2, 1.8, 2.4, and 3.0 dS m-1) and four concentrations of proline (0, 5, 10, and 15 mM). Each treatment combination was replicated four times, and each experimental plot consisted of two sour passion fruit plants, resulting in a total of 160 experimental units. Irrigation with water having an electrical conductivity of 0.6 dS m-1 induced a reduction in relative water content and gas exchange and increased electrolyte leakage in the leaf blade of sour passion fruit plants. Irrigation with water exhibiting an electrical conductivity within the range of 1.3 to 1.8 dS m-1 stimulated the biosynthesis of photosynthetic pigments in the sour passion fruit cultivar 'BRS GA1', as observed 66 days after sowing. Foliar application of proline at concentrations ranging between 4.5 and 6.5 mM resulted in increased stomatal conductance, transpiration rates, CO2 assimilation rates, instantaneous carboxylation efficiency, and chlorophyll content of sour passion fruit plants.