GENE EXPRESSION OF NIFX IN BROAD BEAN ROOT NODULES UNDER RHIZOBIAL INOCULATION AND MOLYBDENUM APPLICATION
DOI:
https://doi.org/10.36103/bm508w95Keywords:
Biofertilizers ,, Cultivars, ,Food Security ,, Plant-based protein ,, SustainabilityAbstract
This study aims to investigate the expression of the nifX gene under the influence of bacterial inoculation and molybdenum application in selected cultivars of broad bean (Vicia faba L.),
A field study was conducted in the winter season of 2023–2024 in the research fields of Baghdad University to evaluate the effect of Rhizobium leguminosarum inoculation and foliar application of molybdenum (Mo) on the root characteristics and expression of the nitrogen-fixing nifX gene in on broad bean (Vicia faba L.) cultivars. The experiment was laid out in a randomized complete block design (RCBD) in a split-split plot arrangement with three replications, that included bacterial inoculation (Bo: control, no inoculation; B₁: 2 × 10⁸ CFU mL⁻¹), molybdenum concentrations (M₀: 0 mg L⁻¹, M₁: 5 mg L⁻¹, M₂: 10 mg L⁻¹), and three broad bean cultivars (V₁: Hannaoui, V₂: Spanish, V₃: Loz). The results revealed an inverse relationship between CT values and gene expression, where both bacterial inoculation and molybdenum application enhanced nifX gene expression. The highest nifX expression levels were observed in treatments V1B1 M2, V2B1M1, and V₃B₁M₁, with the Hannaoui cultivar exhibiting peak expression at 10 mg L⁻¹ Mo, while Spanish and Loz cultivars performed optimally at 5 mg L⁻¹ Mo. Notably, the V₁M₁B₁ treatment recorded the highest active nodule count (845 nodules plant⁻¹) and root dry weight (48.935 g), highlighting the synergistic role of Rhizobium inoculation and Mo supplementation in improving nitrogen fixation efficiency and root growth traits in broad bean
Received: 24/2/2025
Accepted: 4/6/2025
Published: 2026/4/30
References
Al-Rawi, Kha’ash Mahmoud, and Khalaf Allah. 2000. Design and Analysis of Agricultural Experiments. Mosul, Iraq: Dar al-Kutub for Printing and Publishing, Mosul University, 489 p.
Al-Shakarchi, M. A. and Hisyan, W.J. 2021. Isolation and diagnosis of Rhizobium bacteria isolated from the root nodules of leguminous plants and studying their plasmid content. Journal of Education and Science. 30(1):141-157.DOI:10.33899/edusj.2020.127846.1098
Beck, D. P., L. A. Materon, and F. Afandi. 1993. Practical Rhizobium-Legume Technology Manual. Technical Bulletin No. 19. Aleppo, Syria: International Center for Agricultural Research in the Dry Areas (ICARDA).
Black CA. 1965a. Methods of soil analysis. Part 2: Chemical and microbiological properties. Am. Soc. Agron. Inc, Madison, Wisconsin, USA.
Black, M., P. Moolhuijzen, B. Chapman, R. Barrero, J. Howieson, M. Hungria, and M. Bellgard. 2012. The Genetics of Symbiotic Nitrogen Fixation: Comparative Genomics of 14 Rhizobia Strains by Resolution of Protein Clusters. Genes 3, no. 1: 138–166. https://doi.org/10.3390/genes3010138 .
Brom, S., A. García de los Santos, L. Gervantes, R. Palacios, and D. Romero. 2000. In Rhizobium etli Symbiotic Plasmid Transfer, Nodulation, and Cellular Growth Require Interaction Among Different Replicons. Plasmid 44, no. 1: 34–43.
Carrion, V. J., J. Perez-Jaramillo, V. Cordovez, V. Tracanna, M. de Hollander, D. Ruiz-Buck, L. W. Mendes, W. F. J. van Ijcken, R. Gomez-Exposito, S. S. Elsayed, P. Mohanraju, A. Arifah, J. van der Oost, J. N. Paulson, R. Mendes, G. P. van Wezel, M. H. Medema, and J. M. Raaijmakers. 2019. Pathogen-Induced Activation of Disease-Suppressive Functions in the Endophytic Root Microbiome. Science 366, no. 6465: 606–612. https://doi.org/10.1126/science.aaw9285.
Gedamu, S. A., E. A. Tsegaye, and T. F. Beyene. 2021. Effect of Rhizobial Inoculants on Yield and Yield Components of Faba Bean (Vicia faba). Frontiers in Microbiology 12: article 634345, 1–10. https://doi.org/10.3389/fmicb.2021.634345
Kliewer, W. M., and W. K. Kennedy. 1978. Studies on Response of Legumes to Molybdenum and Lime Fertilization on Mardin Silt Loam Soil. Soil Science Society of America Journal 24, no. 4: 377–380.
Lee, S., A. Reth, D. Meletzus, M. Sevilla, and C. Kennedy. 2000. Characterization of a Major Cluster of nif, fix, and Associated Genes in a Sugarcane Endophyte, Acetobacter diazotrophicus. Journal of Bacteriology 182, no. 24: 7088–7091. https://doi.org/10.1128/JB.182.24.7088-7091.2000 .
Liu, H., J. Li, L. C. Carvalhais, C. D. Percy, J. Prakash Verma, P. M. Schenk, and B. K. Singh. 2021. Evidence for the Plant Recruitment of Beneficial Microbes to Suppress Soil-Borne Pathogens. New Phytologist 229, no. 5: 2873–2885. https://doi.org/10.1111/nph.16952 .
MacLean, A. M., T. F. Turlough, and J. S. Michael. 2007. Genomes of the Symbiotic Nitrogen-Fixing Bacteria of Legumes. Plant Physiology 144, no. 2: 615–622. https://doi.org/10.1104/pp.107.098034 .
Manolikaki, I., and E. Diamadopoulos. 2019. Positive Effects of Biochar and Biochar-Compost on Maize Growth and Nutrient Availability in Two Agricultural Soils. Communications in Soil Science and Plant Analysis 50, no. 1: 1–15. https://doi.org/10.1080/00103624.2019.1566468 .
Nonaka, A., H. Yamamoto, N. Kamiya, H. Kotani, H. Yamakawa, Tsujimoto, and Y. Fujita. 2019. Accessory Proteins of the Nitrogenase Assembly, NifW, NifX/NafY, and NifZ, Are Essential for Diazotrophic Growth in the Nonheterocystous Cyanobacterium Leptolyngbya boryana. Applied and Environmental Microbiology 85, no. 24: e01895-19. https://doi.org/10.1128/AEM.01895-19 .
Pandit, N. R., et al. 2020. Nutrient Effect of Various Composting Methods with and without Biochar on Soil Fertility and Maize Growth. Archives of Agronomy and Soil Science 66, no. 2: 250–265. https://doi.org/10.1080/03650340.2019.1610168 .
Pankievicz, V., T. B. Irving, L. G. Maia, and J. M. Ané. 2019. Are We There Yet? The Long Walk Towards the Development of Efficient Symbiotic Associations Between Nitrogen-Fixing Bacteria and Non-Leguminous Crops. BMC Biology 17, no. 1: 1–17. https://doi.org/10.1186/s12915-019-0662-8 .
Sabouh, Mahmoud, Maha Latif Hadi, Mukhlis Shaherli, and Ahmad Saad al-Din Dabo. 2011. Field Crop Cultivation (Practical Part). Damascus: Damascus University Press, Faculty of Agricultural Engineering, 211–234.
Salman, A. K. A., and W. A. Aljuboori. 2019. Determination of Gene Expression (WRKY1) of Some Tomato Genotypes Under Water Stress. Plant Archives 19, Supplement 2: 1199–1201.
Shah, V. K., P. Rangaraj, R. Chatterjee, R. M. Allen, J. T. Roll, G. P. Roberts, and P. W. Ludden. 1999. Requirement of NifX and Other nif Proteins for In Vitro Biosynthesis of the Iron-Molybdenum Cofactor of Nitrogenase. Journal of Bacteriology 181, no. 9: 2797–2801.
https://doi.org/10.1128/JB.181.9.2797-2801.1999 .
Sergey, A.B., Pavel, Y.K., Gennady, I.K. and Mikhail, G.D. (2023). Tracing the Element: The Molecular Bases of Molybdenum Homeostasis in Legume. 2,3 Agronomy, 13, 2300. https://doi.org/10.3390/agronomy13092300
Spaepen, S., J. Vanderleyden, and R. Remans. 2007. Indole-3-Acetic Acid in Microbial and Microorganism-Plant Signaling. FEMS Microbiology Reviews 31, no. 4: 425–448. https://doi.org/10.1111/j.1574-6976.2007.00072.x .
Togay, Y., N. Togay, and Y. Dogan. 2008. Research on the Effect of Phosphorus and Molybdenum Applications on the Yield and Yield Parameters in Lentil (Lens culinaris Medic.). African Journal of Biotechnology 7, no. 9: 1291–1295.
Youseif, S. H., F. H. Abd El-Megeed, and S. A. Saleh. 2017. Improvement of Faba Bean Yield Using Rhizobium /Agrobacterium Inoculant in Low-Fertility Sandy Soil. Agronomy 7, no. 1: 2–12. https://doi.org/10.3390/agronomy7010002
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