Histopathological aspects of resistance in wheat to Puccinia triticina, induced by Pseudomonas protegens CHA0 and β-aminobutyric acid

Abstract

After perception of specific biotic or abiotic stimuli, such as root colonization by rhizobacteria or selected chemicals, plants can enhance their basal resistance against pathogens. Due to its likely sustainability, this induced resistance will be valuable for disease management in agriculture. This study examined resistance against wheat leaf rust (Puccinia triticina) induced by Pseudomonas protegens CHA0 (CHA0) and β-aminobutyric acid (BABA). Seed dressing with CHA0 reduced the number of sporulating pustules on leaves, and expression of resistance was visible as necrotic or chlorotic leaf flecks. Beneficial effect of CHA0 on wheat seedlings growth was observed in when they were challenged or not with leaf rust. BABA was tested at 10, 15 or 20 mM, and a dose-dependent reduction of leaf rust infections was observed with greatest protection at 20 mM. However, BABA treatment repressed plant growth at 20 mM. Balancing the BABA impact on plant growth and its protective capacity, 15 mM of the compound was selected as suitable to protect wheat seedlings against leaf rust, with the least impact on vegetative host growth. Histological aspects of the pathogen infection process was studied to understand mechanisms of behind the observed resistance. The pre-entry process was not affected by the two resistance inducers, but both treatments reduced fungus penetration and haustorium formation. Timing and amplitude of the resistance reactions were different after bacterial or chemical induction, leading to different levels of resistance. During fungal colonization of host tissues, high deposition of callose and accumulation of H2O2 in both CHA0- and BABA-treated plants indicated important contributions to resistance.

The effect of Beta-aminobutyric acid (BABA) on Staphylococcus aureus bacteria and some interleukins

“…The dosing stages also had a role in the disappearance of the bacteria . This agrees with what was indicated by [14], that the BABA act as an antibacterial by the ability of the amino acid to increase the resistance of animals and strengthen their immune system and thus reduce the proliferation of bacteria. The study done by Jasim et al, [ 11 ] , shown in their research that BABA has a beneficial impact on bacterial resistance against staphylococcus bacteria when exposed to acid.…”

The Nematode Signaling Molecule ascr#18 Induces Prepenetration Defenses in Wheat Against a Leaf Rust Fungus

“…Induced resistance against Puccinia triticina has also achieved by treating wheat (cv. Arina) with the bene cia bacterium Pseudomonas protegens CHA0 (by seed coating) and the compound β-aminobutyric acid (BABA) (soil drenching) (Bellameche et al 2021). BABA was tested at high concentrations (10-20 mM), and a dose-dependent reduction of pustule formation was observed with greatest protection at 20 mM.…”

Phosphate solubilizing Pseudomonas and Bacillus combined with rock phosphates promoting tomato growth and reducing bacterial canker disease

“…While infection of the plant with Cmm did not significantly increase the H 2 O 2 level (0.125 μg g −1 FW) compared with the control seedlings (0.115 μg g −1 FW), this level was almost doubled during the PsT-04c and PsT-130 treatments with approximately 0.200 μg g −1 FW. Accumulation of H 2 O 2 was reported as the mechanism of induced systemic resistance, following treatment by Pseudomonas biocontrol agents (De Vleesschauwer and Hoefte, 2006;Bellameche et al, 2021). H 2 O 2 plays a central role in plant resistance to pathogens as it can activate several defense reactions including the strengthening of physical barriers and development of the hypersensitivity reaction.…”