Bacillus cabrialesii: Five Years of Research on a Novel Species of Biological Control and Plant Growth-Promoting Bacteria

Enhancing the Mechanical Properties and Water Permeability of Pervious Planting Concrete: A Study on Additives and Plant Growth

Pervious planting concrete (PPC) is in line with the concept of ecological environmental protection. However, due to its own porous structure, it is difficult to obtain excellent mechanical properties and water permeability at the same time, which hinders its promotion and application. In this paper, natural gravel (NG), ordinary Portland cement (OPC), polyvinyl alcohol latex powder (PVAP) and polycarboxylate superplasticizer (PS) were used to prepare the PPC, and its mechanical properties and water permeability were studied. Three kinds of plants were planted in the PPC and their planting properties were studied. At the same time, the effect of Bacillus on the planting properties was studied. The results show that when the water-binder ratio (W/B) was 0.28 and the PVAP content was 0.8%, both the mechanical properties and water permeability of the PPC were optimal. The compressive strength and permeability coefficient were 14.2 MPa and 14.48 mm/s, respectively. The mechanical properties and water permeability of PPC prepared with 10~20 mm NG were better than those prepared with 5~10 mm NG. Among the three plants, the germination rate and growth of Elymus dahuricus Turcz (EDT) were the best. The incorporation of Bacillus can optimize its planting properties and promote the effective combination between plants and the PPC substrate.

The Contribution of Hormonal Changes to the Protective Effect of Endophytic Bacterium Bacillus subtilis on Two Wheat Genotypes with Contrasting Drought Sensitivities under Osmotic Stress

A comparative analysis was conducted to evaluate the effects of seed priming with endophytic bacterium Bacillus subtilis 10-4 (BS) on the hormonal system and cell wall tolerance (lipid peroxidation (LPO), electrolyte leakage (EL), and root lignin deposition) of two Triticum aestivum L. (wheat) varieties with contrasting drought sensitivities (Ekada 70-drought-tolerant (DT); Salavat Yulaev-drought-sensitive (DS)) under normal conditions and 12% polyethylene glycol-6000 (PEG)-induced osmotic stress. The results showed that under normal conditions, the growth stimulation in wheat plants by BS was attributed to changes in the hormonal balance, particularly an increase in endogenous indole-3-acetic acid (IAA) accumulation. However, under stress, a significant hormonal imbalance was observed in wheat seedlings, characterized by a pronounced accumulation of abscisic acid (ABA) and a decrease in the levels of IAA and cytokinins (CK). These effects were reflected in the inhibition of plant growth. BS exhibited a protective effect on stressed plants, as evidenced by a significantly lower amplitude of stress-induced changes in the hormonal system: maintaining the content of IAA at a level close to the control, reducing stress-induced ABA accumulation, and preventing CK depletion. These effects were further reflected in the normalization of growth parameters in dehydrated seedlings, as well as a decrease in leaf chlorophyll degradation, LPO, and EL, along with an increase in lignin deposition in the basal part of the roots in both genotypes. Overall, the findings demonstrate that BS, producing phytohormones, specifically IAA and ABA, had a more pronounced protective effect on DT plants, as evidenced by a smaller amplitude of stress-induced hormonal changes, higher leaf chlorophyll content, root lignin deposition, and lower cell membrane damage (LPO) and permeability (EL) compared to DS plants.