Brevibacillus DesertYSK and Rhizobium MAP7 stimulate the growth and pigmentation of Lactuca sativa L.

Abstract

Background Applying microbial biostimulants during crop cultivation allows for higher sustainability levels. It reduces the need for fertilizers and environmental contaminants while enhancing plant quality. This study assessed 13 endophytic bacteria, 4 newly isolated, and 9 donated, for plant growth-promoting capabilities. Quantitative assessments of indole acetic acid (IAA), gibberellic acid (GA3), siderophores, ammonia, exopolysaccharides, volatile HCN, and phosphate solubilization, along with Bray–Curtis cluster analyses were performed. Results Upon the results we selected RhizobiumMAP7, Brevibacillus DesertYSK, Pseudomonas MAP8, BacillusMAP3, Brevibacillus MAP, and Bacillus DeltaYSK to evaluate their effects on Lactuca sativa growth and pigmentation in a 30-day greenhouse pot experiment. Both Brevibacillus DesertYSK and Rhizobium MAP7surpassed other strains in growth promotional effects. They doubled shoot length (12 and 12.3 cm, respectively, when compared with 7 cm for control after 30 days), and fresh weight (0.079 and 0.084 g, respectively, when compared with 0.045 g for control after 30 days), and increased root length by at least 3-fold when compared with control (4.5 and 3.5 cm, respectively, when compared with 1.2 cm for control after 30 days). Chlorophyll content also exhibited at least a 2-fold significant increase in response to bacterization compared with control. Conclusions This strain superiority was consistent with the in vitro assays data that showed strains capability as IAA and GA3producers. Also, strains were highly capable ammonia and siderophore producers and phosphate solubilizers, providing considerable hormone and nutrient levels for L. sativa plantsleading to improved growth parameters and appearance. These data support the notion that nodule-based bacteria are potential plant growth-promoting bacteria (PGPB) that may be used on a wider scale rather than just for legumes.

Enterobacter cloacae Induces SA-Dependent Systemic Acquired Resistance of Zea mays Against Fusarium oxysporum

“…4) which indicates improved photosynthetic activity. This improved pigmentation might be attributed to increased iron availability by siderophores and ammonia provided by Enterobacter (Mowafy et al 2023). The promoted root growth attained by Enterobacter leads to better nutrition absorption, which subsequently leads to an increase in chlorophyll contents (El-Ganainy et al 2023).…”

Panchagavya-Derived Brevibacillus brevis S1-3: Insights from the Draft Genome on its Antimicrobial and Plant Growth-Promoting Ability

“…2024;18(1):467-475. https://doi.org/10.22207/JPAM.18.1.30 have also been made. 37 Bacillus brevis has been found to provide a multi-pronged defense against fungal and microbial pathogens by means of extracellular secretion of gramicidin S, gramicidin A, and a biosurfactant, thereby functioning as a biological control agent and aiding plant growth, apart from the production of PGPs. 38…”