Plant health is necessary for food security, which is a key determinant of secure and sustainable food production systems. Deficiency of soil nutrients and invasion of plant pathogens or insects are the main destroyers of the world’s food production. Synthetic fertilizers and chemical-based pesticides are frequently employed to combat the problems. However, these have negative impacts on microbial ecosystems and ecosystem functioning. Rhizosphere microorganisms have demonstrated their potency to improve or manage plant nutrients to encourage plant growth, resulting in increased yield and quality by converting organic and inorganic substances around the rhizosphere zone into available plant nutrients. Besides regulating nutrient availability and plant growth enhancement, rhizobacteria or fungi can restrict plant pathogens that cause disease by secreting inhibitory chemicals and boosting plant immunity to combat pests or pathogens. Thus, rhizosphere microorganisms are viewed as viable, alluring economic approaches for sustainable agriculture as biofertilizers and biopesticides. This review provides an overview of the role of rhizosphere microorganisms in soil nutrients and inducing of plant defenses. Moreover, a discussion is presented surrounding the recent consequences of employing these microorganisms and a sustainable strategy towards improving fertilization effectiveness, and encouraging stronger, more pest-resistant plants.

Hericium erinaceus (Bull.:Fr) Pers. is a medicinal mushroom that has various health benefits and is a rich source of bioactive compounds and antioxidant activity. In recent years, H. erinaceus has been considered for its many medicinal properties and is widely consumed in Asian countries. Remarkably, the effect of mushroom cultivation using substrates composed of soybean meal by-products on growth, as well as the enhancement of bioactive compounds and antioxidant activity, was evaluated. Our results confirmed that using soybean meal-produced H. erinaceus displayed a higher mycelial growth and biological efficiency than the control treatment. Bioactive compounds with triterpenoid content and total phenolic content of H. erinaceus grown on soybean meal contained the highest values at 56.78–69.15 mg Urs/g DW and 15.52–16.07 mg GAE/g DW, respectively, while H. erinaceus grown on the control treatment had the lowest value at 32.15 mg Urs/g DW and 7.75 mg GAE/g DW, respectively. In addition, H. erinaceus cultivated on soybean meal had higher DPPH activities than those grown on the control treatment, with IC₅₀ values of 0.67–0.89 and 1.08 mg/mL, respectively. Therefore, this study provided baseline information on the potential role of soybean meal by-product substrates in H. erinaceus growth and their effect on bioactive compounds and antioxidant activity.

This study explores the impact of exogenous salicylic acid (SA) alongside conventional treatment by farmers providing positive (Mancozeb 80 % WP) and negative (water) controls on rice plants (Oryza sativa L.), focusing on antioxidant enzyme activities, phytohormone levels, disease resistance, and yield components under greenhouse and field conditions. In greenhouse assays, SA application significantly enhanced the activities of peroxidase (POX), polyphenol oxidase (PPO), catalase (CAT), and superoxide dismutase (SOD) within 12–24 h post-inoculation (hpi) with Magnaporthe oryzae. Additionally, SA-treated plants showed higher levels of endogenous SA and indole-3-acetic acid (IAA) within 24 hpi compared to the controls. In terms of disease resistance, SA-treated plants exhibited a reduced severity of rice blast under greenhouse conditions, with a significant decrease in disease symptoms compared to negative control treatment. The field study was extended over three consecutive crop seasons during 2021–2023, further examining the efficacy of SA in regular agricultural practice settings. The SA treatment consistently led to a reduction in rice blast disease severity across all three seasons. Yield-related parameters such as plant height, the number of tillers and panicles per hill, grains per panicle, and 1000-grain weight all showed improvements under SA treatment compared to both positive and negative control treatments. Specifically, SA-treated plants yielded higher grain outputs in all three crop seasons, underscoring the potential of SA as a growth enhancer and as a protective agent against rice blast disease under both controlled and field conditions. These findings state the broad-spectrum benefits of SA application in rice cultivation, highlighting its role not only in bolstering plant defense mechanisms and growth under greenhouse conditions but also in enhancing yield and disease resistance in field settings across multiple crop cycles. This research presents valuable insights into the practical applications of SA in improving rice plant resilience and productivity, offering a promising approach for sustainable agriculture practices.

Kale has gained popularity as a healthy food choice due to its rich nutrient profile. However, kale production systems are also affected by various pests and diseases, especially plant pathogenic bacteria, such as Pectobacterium carotovorum. The purpose of this research was to investigate the biocontrol activity of the Pseudomonas fluorescens strain SP007s and develop a formulation that provides stability, long shelf life, and disease control, as well as promoting growth in kale; we expect this formulation to have further commercial applications in the cultivation of kale. The results indicated that a unique mixture of paper sludge, sugar sludge, and glycerol at 40% relative humidity promoted SP007 survival for 6 months at room temperature (30 °C) with measures of 5.92 × 10⁶ CFU/g. This treatment maintained the control efficacy of P. carotovorum in infected soil within 28 days of soil drenching. We evaluated the SP007s formula for controlling soft rot disease in greenhouse conditions, and our results revealed that it can reduce the disease in kale by 65.2% and promotes growth in terms of canopy width, shoot height, number of leaves per plant, fresh weight, and dry weight, which were superior to the control. In addition, the formula can induce the accumulation of endogenous salicylic acid and phenolic compounds, as well as a systemic acquired resistance pathway in the plant defense system. Therefore, the formula of SP007s can be a promising novel biocontrol formula for use in kale production, as it promotes plant growth and acts against P. carotovorum causal soft rot disease.

Acidovorax avenae subsp. avenae (Aaa) caused bacterial leaf streak of corn. To minimize the risk of introducing this pathogen, sorbitol neutral red (SNR) agar was integrated with bio-polymerase chain reaction (PCR) to detect Aaa in commercial corn seeds. A set of 32-random samples was initially detected by sorbitol neutral red (SNR). Colony forming units (CFU) of Aaa from SNR plates and seed extracts was confirmed diagnostic tools by bio-PCR. The bio-PCR produced the positive band from 6, 8 and 10 samples of waxy corn, sweet corn, and field corn with 4, 4, 4, 6, 30, and 40%; 12.5, 14, 16, 23, 30, 30, 30, and 68.2% and 2, 4, 6, 10, 14.3, 20, 20, 30, 30, and 30% respectively, that correlated with the incidence of Aaa detected on SNR agar. We also demonstrated Aaa transmission from sweet corn seeds to seedlings by plant bioassay. As expected, seeds did not show evident symptoms of bacterial leaf streak, but typical Aaa fluid colonies were reisolated indicating seedling transmission of Aaa. The two methods studied provide an effective quantification of Aaa in corns seeds. This suggests that certification of corn seeds against Aaa should be developed. Key words: Bio-PCR, sorbitol neutral red (SNR) agar, contaminated seeds, waxy corn, sweet corn, field corn.

The study of antagonistic bacterial strains isolated from the soil around durian tree roots demonstrated their ability to inhibit the growth of Phytophthora palmivora. The pathogens were screened from 30 samples collected around durian trees (leaves, soil around the roots, and debris under the tree) showing symptoms of root and stem rot disease. A total of 17 pathogen strains were isolated and grouped into 3 groups, TNP05, MNP13, and KNP21, originating from Chanthaburi province, Thailand. When P. palmivora isolates were tested for pathogenicity on leaves and durian trees, it was found that the strain MNP13 had the highest capacity to cause root and stem rot disease. A total of 196 beneficial bacteria isolates were collected from several samples around durian trees. The samples included leaves, soil surrounding the roots, and organic debris beneath the trees. Based on their colony characteristics on nutrient glucose agar (NGA), these isolates were divided into 8 groups. The efficacy of the beneficial bacteria against root and stem rot disease was tested using the Dual culture method and arranged in a Completely Randomized Design (CRD) with 5 replications. The experiment showed that bacterial isolates NJTU05, NJTU10, and NJTU13 effectively inhibited the growth of P. palmivora isolate MNP13, with inhibition rates of 76.66, 67.59, and 69.07%, respectively, compared to chemical control using metalaxyl 80% WP. Among the tested strains, NJTU05 was identified as the most effective bacterial strain for controlling major durian diseases. Biochemical identification and 16S rRNA sequencing revealed that bacterial strain NJTU05 was closely related to Brevibacillus formosus with a 99.70% identity.