Plant growth–promoting rhizobacteria (PGPR) are beneficial soil bacteria that colonize the rhizosphere and enhance plant growth through direct and indirect mechanisms, including nutrient solubilization, phytohormone production, suppression of phytopathogens, and activation of plant defense mechanisms. PGPR‐based techniques are gaining popularity in sustainable agriculture as environmentally friendly alternatives to chemical fertilizers and insecticides. Although PGPR have been extensively studied, the molecular mechanisms behind these beneficial interactions are still dispersed throughout the literature. Recent advances in molecular biology and high‐throughput omics technology have rapidly expanded the identification of genes, pathways, and regulatory networks associated with PGPR activities. However, these findings are often reported in isolation, and a consolidated and integrative synthesis of molecular mechanistic insights is lacking, restricting a system‐level knowledge of PGPR–plant interactions and impeding the rational development of effective bioinoculant formulations. Therefore, a comprehensive review is required to consolidate current understanding and elucidate how molecular pathways support PGPR‐mediated plant growth promotion and biocontrol. This review aims to provide an updated synthesis of molecular mechanisms governing PGPR‐mediated biofertilization and biocontrol. The main mechanisms discussed are microbial‐driven nutrient solubilization and mobilization, phytohormone biosynthesis and signaling, secretion of antimicrobial metabolites and lytic enzymes, and induction of plant systemic resistance pathways. The emphasis is on how these molecular mechanisms combine and work together to promote plant growth, stress tolerance, and disease resistance. This review emphasizes the functional diversity of PGPR and their potential application in next‐generation biofertilizers and biopesticides by incorporating new genomic and molecular findings. A clearer mechanistic framework will help to build more consistent and efficient PGPR‐based technologies, reducing reliance on synthetic agrochemicals and improving soil health and crop production systems.

Sorghum is one of the staple food crops in Tigray, northern Ethiopia. Despite this, limited research attention was given to the nutritional and antinutritional profiling of sorghum. Thus, this research was initiated to profile and evaluate the variabilities in protein, starch, minerals, flavonoid, tannin, and antioxidant activities among sorghum landraces of Tigray, northern Ethiopia. Protein and starch were analyzed using an infrared spectrophotometer, whereas mineral elements were estimated using an atomic absorption spectrophotometer. Antioxidant activity was analyzed using DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging, ferric-reducing antioxidant power, and phosphomolybdenum assays. The result revealed significant variation among the landraces for all the evaluated parameters. Protein and starch contents ranged from 6.21 to 18% and 33.42 to 78.30%, respectively. Wider variations were observed for Fe (32–101), Zn (16.9–42.98), Cu (1.48–5.25), Mn (9.21–20.23), and Cr (0–1.5) as measured in mg/100 g. The variabilities were high for total flavonoid (0–665 mg CE/g) and tannin (0.18–7.5 mgCE/100 g). DPPH (EC₅₀ = 29.09–818.37 µg/mL), ferric reducing antioxidant power (17.85–334.81 mgAAE/g), and total antioxidant activity (1.71–63.88 mgBHTE/g) were also highly variable among the samples. The relationship between seed color and phenolics, as well as antioxidant activities, are discussed. Multivariate analysis revealed that the landraces were clustered into four distinct groups. The rich genetic diversity in the nutritional and antinutritional attributes may be an opportunity for breeding for grain quality improvements of sorghum that, in turn, helps in addressing malnutrition.

The emerging oilseed crop Sesamum indicum, also known as the queen of oilseeds, is being grown globally for its oil content for medicinal and nutritional values. One of the key challenges of sesame cultivation is its low productivity. In the present study, sodium azide (NaN₃) was used as a chemical mutagen. The aim of this study was to examine the effect of NaN₃ on quantitative and qualitative stem traits in the M2 generation of Ethiopian sesame (Sesamum indicum L.) genotypes. Seeds of fourteen sesame genotypes were used in this study and germinated and grown under greenhouse conditions. Different qualitative and quantitative data were collected and analyzed. Traits such as plant height, ground distance to first distance, and internode length were significantly affected by NaN₃ treatment. The highest plant height was recorded in the control on Humera 1 and Baha Necho genotypes, while the lowest was observed on Setit 2 and Hirhir treated with the chemical. The highest ground distance to the first branch was observed in Gumero, while the least ground distance was recorded in Setit 1 in the treated and control genotypes, respectively. The best internode length was recorded on Setit 2 and ADI in the control, while the lowest internode length was observed in Setit 1 genotype treated with sodium azide. Genotypes such as ACC44, ADI, Baha Necho, Borkena, Gonder 1, and Setit 1 treated with NaN₃ have showed glabrous type of stem hairiness. All the fourteen genotypes (both treated and control) were clustered into four groups. In conclusion, we observed a highly significant variation among the genotypes due the effect of the chemical and genotypes themselves. Hence, this report would create more genetic diversity for further sesame genetic research improvements.

Nowadays, the inoculation of plant growth-promoting rhizobia in leguminous and nonleguminous crops is given great emphasis as it improves germination and seedling vigor, resulting in increased yields. In this study, 32 rhizobia isolates were obtained from five different sampling sites in Tigray, Ethiopia. Based on morphological, biochemical, and confirmatory tests, including sugar fermentation, the isolates were identified as belonging to the rhizobia genera. In vitro assessment of plant growth-promoting properties revealed that all isolates produced indole-acetic-acid, ammonia, and solubilized phosphate, except TA8, which did not solubilize phosphate. Only 3 isolates (TA1, TA2, and TA8) produced hydrogen cyanide, so they can be used as biocontrol agents. Nineteen isolates showed a growth reduction activity against Fusarium oxysporum, with a percent inhibition range of 34.2%–65.8%. All isolates tolerated a pH range of 4.0–9.0. The isolates showed growth variations in various temperatures and salt concentrations. A few isolates were tolerant up to 45°C temperature and 6% (w/v) CaCl₂ and NaCl concentrations. Inoculation of the isolates to wheat seeds increased seed germination, seedling shoot/root length, and seedling vigor index compared to the positive and negative controls. Isolates KO3, KO4, ME3, and TA5 increased seed germination by 4%. KO1 (11.60 cm) and TA7 (11.70 cm) showed a significantly enhanced shoot length, and ME3 showed a maximum root length (13.90 cm). SH1, KO2, and the positive control showed a significant ( ) increase in pea seed germination (by 20%) compared to the negative control. The positive control had the longest field pea shoot (5.70 cm), and isolate TA9 had the longest field pea root (5.32 cm) compared to the negative control. Generally, the wheat and field pea seedlings responded differently to the inoculation of different isolates. This study shows that Tigray soils harbor a variety of rhizobia species, which can be used as plant growth-promoting and biocontrol agents.

Sorghum is an important crop in the livelihoods of Kunama and Tigrayan farmers in Northern Ethiopia and we present here a study of what factors have shaped the genetic diversity of the varieties cultivated in neighboring communities of the two ethnolinguistic groups. Using a combination of methods from crop science and cultural anthropology, we investigate patterns of historical and contemporary relationships between crop genetic diversity and cultural and social factors. The spatial genetic structure reveals patterns of ethnolinguistic differentiation and admixture that reflect deep affinities between cultures and crops, but the seed systems of the two communities are also open to exchange and gene-flow. Our findings highlight the importance of understanding cultural factors for genetic resource conservation, as well as for plant breeding and seed system development efforts.

Multicellular organisms consist of heterogeneous mixture of different cell types having distinct functions, morphology, physiology, and gene expression programs. This heterogeneity nature of tissues has been a challenge for studying the specific cell types independently and hence it was difficult to uncover the function of each cell type. For the effective analysis of specific cell types, the cell of interest needs to be isolated from neighboring cells or tissues. Even though this can be done using manual dissection, it has several limitations such as contamination and time consuming. To avoid the drawbacks this isolation is preferably performed using laser capture microdissection (LCM). LCM is a powerful tool for harvesting and subsequent molecular analysis of distinct cell populations under direct microscopic visualization. It has been applied for transcriptomics of several plant tissues including: transcriptional profiling of the Arabidopsis thaliana embryo and isolation of RNA from shoot apical meristem of Maize. Careful tissue preparations such as fixation, embedding, and sectioning are essential prerequisites for the success of LCM.