Application of Cyanobacteria (Roholtiella sp.) Liquid Extract for the Alleviation of Salt Stress in Bell Pepper (Capsicum annuum L.) Plants Grown in a Soilless System

Research in plant pathology has increasingly focused on developing environmentally friendly, effective strategies for controlling plant diseases. Cyanobacteria, including Desmonostoc muscorum, Anabaena oryzae, and Arthrospiraplatensis, were applied to Capsicum annuum L. to induce immunity against Fusarium wilt. Soil irrigation and foliar shoots (FS) application were used in this investigation. The disease symptoms, disease index, osmotic contents, total phenol, Malondialdehyde (MDA), hydrogen peroxide (H2O2), antioxidant enzymes (activity and isozymes), endogenous hormone content, and response to stimulation of defense resistance in infected plants were assessed. Results demonstrated that using all cyanobacterial aqueous extracts significantly reduced the risk of infection with Fusarium oxysporum. One of the most effective ways to combat the disease was through foliar spraying with Arthrospira platensis, Desmonostoc muscorum, and Anabaena oryzae (which provided 95, 90, and 69% protection percent, respectively). All metabolic resistance indices increased significantly following the application of the cyanobacterial aqueous extracts. Growth, metabolic characteristics, and phenols increased due to the application of cyanobacteria. Polyphenol oxidase (PPO) and peroxidase (POD) expressions improved in response to cyanobacteria application. Furthermore, treatment by cyanobacteria enhanced salicylic acid (SA) and Indole-3-Acetic Acid (IAA) in the infected plants while decreasing Abscisic acid (ABA). The infected pepper plant recovered from Fusarium wilt because cyanobacterial extract contained many biologically active compounds. The application of cyanobacteria through foliar spraying seems to be an effective approach to relieve the toxic influences of F. oxysporum on infected pepper plants as green and alternative therapeutic nutrients of chemical fungicides.

Section: Discussionsupporting

confidence: 92%

“…After 14 days of cultivation, freeze-dried cyanobacteria biomass was exposed to aqueous extraction [ 35 ]. After washing 100 mg of the cyanobacterial dry biomass in sterile distilled water, the amount was dissolved in 12.5 mL phosphate buffer (0.1 M pH 6.0) for 10 min before sonication (5 s pulses of 8 W over 30 s, on ice).…”

Section: Methodsmentioning

confidence: 99%

Cyanobacteria-Mediated Immune Responses in Pepper Plants against Fusarium Wilt

Abdelaziz

Attia

Salem

et al. 2022

“…Because a cyanobacteria extract was used in our experiment as foliar spraying to enhance physiological and biochemical processes, as well as to control oxidative stress, it had a less significant influence on soil properties than composted bagasse. However, the combined application of composted bagasse and foliar cyanobacteria extracts before planting enhanced the soil characteristics more than a solo treatment [26]. The foliar cyanobacteria extract application includes an efficient content of nitrogen and sulfur that could stimulate the photosynthesis process and, therefore, improve root growth in the soil profile, resulting in an improvement in soil properties as an indirect benefit of cyanobacteria extracts to enhance the characteristics of salt-affected soil in Egypt [27].…”

Section: Discussionmentioning

confidence: 99%

Composted Bagasse and/or Cyanobacteria-Based Bio-Stimulants Maintain Barley Growth and Productivity under Salinity Stress

Alharbi

Hafez

Omara

et al. 2023

Soil and water salinity are among the most fatal environmental challenges that threaten agricultural production worldwide. This study investigated the potential impact(s) of soil amendment using composted bagasse and/or foliar application of cyanobacteria-based bio-stimulants (Arthrospira platensis, also known as Spirulina platensis) to combat the harmful effect(s) of using saline water to irrigate barley plants grown in salt-affected soils during 2020/2021 and 2021/2022. Briefly, the dual application of composted bagasse and cyanobacteria-based bio-stimulants significantly improved the soil properties, buffered the exchangeable sodium percentage (ESP), and enhanced the activity of soil enzymes (urease and dehydrogenase). Moreover, both treatments and their combination notably augmented the water relations of barley plants under salinity stress. All treatments significantly decreased stomatal conductance (gs) and relative water content (RWC) but increased the electrolyte leakage (EL) and balanced the contents of Na+ and K+, and their ratio (K+/Na+) of barley leaves under salinity stress compared with those irrigated with fresh water during the 2020/2021 and 2021/2022 seasons. Additionally, composted bagasse and cyanobacteria-based bio-stimulants diminished the oxidative stress in barley plants under salinity stress by improving the activity of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX). Consequently, the combination of composted bagasse and cyanobacteria extract resulted in superior yield-related traits such as spike length, number of grains per spike, 1000-grain weight, grain yield, straw yield, and harvest index. Collectively, our findings suggest that the integrative application of composted bagasse and cyanobacteria is promising as a sustainable environmental strategiy that can be used to improve soil properties, plant growth, and productivity of not only barley plants but also maybe other cereal crops irrigated with saline water in salt-affected soil.

“…Protein hydrolysates, especially those that contain antioxidant peptides, are obtained from natural components, and many researchers and scholars consider them biostimulants because of their minimum side effects, easy absorption, low cost, high activity, and lower molecular weight [ 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 ]. Protein hydrolysates and peptides can be used as notable ingredients in the formulation of functional foods [ 131 , 132 , 133 , 134 , 135 , 136 , 137 , 138 , 139 , 140 , 141 ].…”

Section: Protein Hydrolysatesmentioning

confidence: 99%

Amino Acids Biostimulants and Protein Hydrolysates in Agricultural Sciences

Sun,

Shahrajabian,

Kuang

et al. 2024

The effects of different types of biostimulants on crops include improving the visual quality of the final products, stimulating the immune systems of plants, inducing the biosynthesis of plant defensive biomolecules, removing heavy metals from contaminated soil, improving crop performance, reducing leaching, improving root development and seed germination, inducing tolerance to abiotic and biotic stressors, promoting crop establishment and increasing nutrient-use efficiency. Protein hydrolysates are mixtures of polypeptides and free amino acids resulting from enzymatic and chemical hydrolysis of agro-industrial protein by-products obtained from animal or plant origins, and they are able to alleviate environmental stress effects, improve growth, and promote crop productivity. Amino acids involve various advantages such as increased yield and yield components, increased nutrient assimilation and stress tolerance, and improved yield components and quality characteristics. They are generally achieved through chemical or enzymatic protein hydrolysis, with significant capabilities to influence the synthesis and activity of some enzymes, gene expression, and redox-homeostasis. Increased yield, yield components, and crop quality; improved and regulated oxidation-reduction process, photosynthesis, and physiological activities; decreased negative effects of toxic components; and improved anti-fungal activities of plants are just some of the more important benefits of the application of phenols and phenolic biostimulants. The aim of this manuscript is to survey the impacts of amino acids, different types of protein hydrolysates, phenols, and phenolic biostimulants on different plants by presenting case studies and successful paradigms in several horticultural and agricultural crops.