Proline and ions accumulation in four Passiflora species under water-saline stress

Abstract

Water-saline stress is one of the factors limiting growth and crop production, with the induction of morphological, structural and metabolic changes in higher plants. This study aimed to evaluate the response of four species with ten accessions of Passiflora to saline stress and drought stress, and the accumulation of proline and content of cationic macronutrients and their relationships with sodium. The plants were grown under controlled conditions for seven months, watered with nutrient solution with additions of NaCl (100 mM) to achieve the desired conductivities (1.5, 2.5, 4.0, and 5.5 dS m-1) and constant substrate humidity of 100%, 66% and 33%. The concentrations of Na+, K+, Ca++, Mg++ and proline in the leaves were determined. Proline accumulation increased in salinized plants, especially in young leaves. Proline increase was evident in accessions tolerant and moderately tolerant to salinity. These results indicate that tolerance to salinity and water stress in Passiflora relates to an improved ability to exclude sodium and greater ability to accumulate proline for osmotic adjustment. The increased salinity of the nutrient solution increased sodium contents, relations Na+/Ca++, Na+/Mg++, Na+/K+, and decreased Ca++, Mg++ and K+ levels, reflecting the nutritional imbalance caused by progressive saline stress.

Produção E Qualidade Pós-Colheita Do Maracujazeiro-Azedo Irrigado Com Águas Salinas E Aplicação Exógena De H2o2

“…A salinidade pode causar efeitos osmóticos e iônicos, limitando-se à produção de carboidratos e proteínas. Desses osmoprotetores, a prolina é um metabólito relacionado ao estresse que auxilia na osmorregulação e favorece o aumento da tolerância a certos níveis de estresse hídrico e salino (SANTOS et al, 2016;SALAZAR et al, 2017;LIMA et al, 2020b). O excesso de sais na água de irrigação também pode causar alterações na permeabilidade das membranas celulares e nas funções fisiológicas das plantas, devido ao estresse osmótico, distúrbios nas relações hídricas e modificações na homeostase iônica (LIMA et al, 2014;LIMA et al, 2015).…”

Salicylic acid does not mitigate salt stress on the morphophysiology and production of hydroponic melon

“…When comparing the IEL of plants cultivated with ECns of 5.4 dS m -1 to that of plants under the lowest level of nutrient solution salinity, an increase of 20.52% was found. Due to the increase in nutrient solution salinity, there may be a nutritional imbalance, affecting the availability of Ca 2+ , an essential element for cell wall formation (Ferraz et al, 2015;Hurtado-Salazar et al, 2017), favoring cell membrane rupture, with the release of ions, which leads to greater loss in integrity and destabilization of the cell membrane (Ataíde et al, 2012). Wanderley et al (2020) cultivated passion fruit under irrigation with saline water (0.3, 1.0, 1.7, 2.4, and 3.1 dS m -1 ) and found that the increase in electrical conductivity of water resulted in a 64.27% increase in electrolyte leakage in the leaf blade of plants subjected to irrigation with water of 3.1 dS m -1 compared to those under the lowest salinity level (0.3 dS m -1 ).…”