Hydrogen Peroxide as Salt Stress Attenuator in Sour Passion Fruit

Abstract

Sour passion fruit is a fruit crop widely cultivated throughout Brazil, due to its adaptation to the tropical climate. However, in semi-arid regions its development is limited by the high concentration of soluble salts in the waters commonly used in irrigation. In this context, exogenous application of low concentrations of hydrogen peroxide can attenuate the damage caused by salt stress. The objective of this study was to evaluate electrolyte leakage, photosynthetic pigments and photochemical efficiency in sour passion fruit cv. BRS Rubi do Cerrado under irrigation with saline waters and foliar application of hydrogen peroxide. A completely randomized design was used, with treatments arranged in split plots, corresponding to five levels of irrigation water salinity - ECw (0.6; 1.2; 1.8; 2.4 and 3.0 dS m−1) and four concentrations of hydrogen peroxide - H2O2 (0; 15; 30 and 45 μM of H2O2) in plots and subplots, respectively. Irrigation with saline water reduced chlorophyll a and total chlorophyll contents of sour passion fruit plants cv. BRS Rubi do Cerrado, at 240 days after transplanting. Hydrogen peroxide at concentration of 15 μM stimulated chlorophyll a and total chlorophyll biosynthesis and, at 45 μM, relieved the effect of 3.0 dS m−1 water salinity on electrolyte leakage in the leaf blade of sour passion fruit. Salt stress did not affect the initial, maximum, variable fluorescence and quantum efficiency of photosystem II of sour passion fruit cv. BRS Rubi do Cerrado.

Peróxido de hidrogênio na mitigação do estresse salino em pimentão

“…Regardless of the H 2 O 2 concentration, the intracellular CO 2 concentration (Ci) in the mesophyll cells increased and transpiration rate (E) decreased as the ECw level was raised, demonstrating the negative effects of salinity on the bell pepper plants. The reduction in E is directly related to partial stomatal closure, since less opening of the stomata will cause transpiration to decrease, restricting the loss of water from the Chl t iCE Ramos et al (2022) worked with the passion fruit crop (Passiflora edulis Sims) under ECw ranging from 0.6 to 3.0 dS m -1 and foliar application of H 2 O 2 and also found beneficial effects on growth and photosynthetic pigments when the plants received the H 2 O 2 concentration of 15 µM. Dantas et al (2022) studied Italian zucchini (Cucurbita pepo L.) under ECw ranging from 2.1 to 6.6 and exogenous application of H 2 O 2 at 20 µM and described similar findings for growth rates and gas exchange.…”

NPK Accumulation, Physiology, and Production of Sour Passion Fruit under Salt Stress Irrigated with Brackish Water in the Phenological Stages and K Fertilization

“…Furthermore, excessive ion concentrations in the soil solution also damage photosynthetically active leaves and can result in chlorosis and early senescence, thus negatively affecting photosynthetic efficiency and production [ 4 ]. In this context, several studies have been carried out evaluating the effects of irrigation with saline water in the passion fruit crop, highlighting changes in gas exchange [ 5 ], photochemical efficiency [ 6 ], synthesis of photosynthetic pigments [ 7 ], and membrane instability [ 8 ], as well as a reduction in production components [ 9 , 10 ] and post-harvest quality [ 11 ]. However, these studies are restricted to the use of water with different levels of salinity throughout the plant development cycle, thus requiring further research, especially to assess the effects of salt stress on the accumulation of NPK, physiology, and production of sour passion fruit plants of the cultivar BRS GA1, one of the most commonly grown in northeast Brazil, at varying phenological stages.…”

“…In this context, several studies have been carried out evaluating the effects of irrigation with saline water in the passion fruit crop, highlighting changes in gas exchange [ 5 , 22 ], photochemical efficiency [ 6 ], synthesis of photosynthetic pigments [ 7 ], and membrane instability [ 8 ], as well as a reduction in production components [ 9 , 10 ] and post-harvest quality [ 11 ]. However, these studies are restricted to the use of water with different levels of electrical conductivity throughout the plant development cycle, thus requiring further research, especially to assess the concentrations of NPK, physiology, and production of Passiflora edulis Sims, cultivar BRS GA1, grown under salt stress in the phenological stages and fertilization with K.…”