Plant Hormones: The Essential Regulators of Growth and Development in Plants Through Complex Signaling Pathways and Interactions

Md. Sohel Rana ¹*, Md. Shakil Ahmed ¹, Tahnia Basher ², Syeda Anjuman Ara Aunni ³

Plant hormones orchestrate growth, stress tolerance, and development. Their manipulation can revolutionize agriculture, enhancing crop productivity and resilience.

Abstract

Background: Plant hormones, also known as phytohormones, are vital for regulating plant growth, development, aynd responses to environmental stimuli. Understanding these hormones, including auxins, cytokinins, gibberellins, abscisic acid, and ethylene, provides insight into how plants manage critical processes such as germination, flowering, and stress responses. Methods: This study explores the roles of plant hormones using controlled greenhouse experiments, genetic analysis, and hormone quantification techniques. Arabidopsis thaliana and rice (Oryza sativa) were used as model organisms. Hormone levels were measured via gas chromatography-mass spectrometry (GC-MS), and the expression of genes involved in hormone signaling pathways was analyzed using qRT-PCR. Results: The study found that auxins significantly influence root development, while cytokinins regulate shoot differentiation. Gibberellins promote stem elongation, abscisic acid induces dormancy and stress tolerance, and ethylene regulates fruit ripening and leaf abscission. The genetic analysis revealed a significant upregulation of specific genes during hormonal treatments, showing the direct link between hormone levels and gene expression. Conclusion: Plant hormones play a pivotal role in shaping plant morphology and adapting to environmental stresses. Understanding these hormonal interactions can contribute to agricultural innovations such as improving crop yields and enhancing stress resistance.

Keywords: plant hormones, auxins, cytokinins, gibberellins, abscisic acid, ethylene, growth regulation, development, signaling pathways, plant physiology

References

Chomczynski, P., & Sacchi, N. (1987). Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Analytical Biochemistry, 162(1), 156-159.

Davies, P. J. (2010). The plant hormones: Their nature, occurrence, and functions. In Plant Hormones (pp. 1-15). Springer.

Finkelstein, R. (2013). Abscisic acid synthesis and response. The Arabidopsis Book, 11, e0166.

Mattoo, A. K., & Suttle, J. C. (1991). The Plant Hormone Ethylene. CRC Press.

Mok, D. W., & Mok, M. C. (2001). Cytokinin metabolism and action. Annual Review of Plant Physiology and Plant Molecular Biology, 52(1), 89-118.

Müller, M., & Munné-Bosch, S. (2011). Rapid and sensitive hormonal profiling of complex plant samples by liquid chromatography coupled to electrospray ionization tandem mass spectrometry. Plant Methods, 7(1), 37.

Murashige, T., & Skoog, F. (1962). A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiologia Plantarum, 15(3), 473-497.

Santner, A., & Estelle, M. (2009). Recent advances and emerging trends in plant hormone signalling. Nature, 459(7250), 1071-1078.

Somerville, C., & Koornneef, M. (2002). A fortunate choice: the history of Arabidopsis as a model plant. Nature Reviews Genetics, 3(11), 883-889.

Taiz, L., & Zeiger, E. (2015). Plant Physiology and Development. Sinauer Associates.

Zhao, Y. (2010). Auxin biosynthesis and its role in plant development. Annual Review of Plant Biology, 61, 49-64.

Hedden, P., & Thomas, S. G. (2012). Gibberellin biosynthesis and its regulation. Biochemical Journal, 444(1), 11-25.

Jones, H. G. (1992). Plants and microclimate: A quantitative approach to environmental plant physiology. Cambridge University Press.

Kende, H. (1993). Ethylene biosynthesis. Annual Review of Plant Biology, 44(1), 283-307.

Kieber, J. J., & Schaller, G. E. (2014). Cytokinins. The Arabidopsis Book, 12, e0168.

McSteen, P. (2009). Auxin and monocot development. Cold Spring Harbor Perspectives in Biology, 1(3), a001479.

Osmont, K. S., Sibout, R., & Hardtke, C. S. (2007). Hidden branches: Developments in root system architecture. Annual Review of Plant Biology, 58, 93-113.

Sakakibara, H. (2006). Cytokinins: Activity, biosynthesis, and translocation. Annual Review of Plant Biology, 57(1), 431-449.

Schaller, G. E., Street, I. H., & Kieber, J. J. (2014). Cytokinin and the cell cycle. Current Opinion in Plant Biology, 21, 7-15.

Stepanova, A. N., & Alonso, J. M. (2009). Ethylene signaling and response: Where different regulatory modules meet. Current Opinion in Plant Biology, 12(5), 548-555.

Swarup, R., & Péret, B. (2012). Auxin transport and gravitropism: Perspectives for future research. Frontiers in Plant Science, 3, 1-9.

Teale, W. D., Paponov, I. A., & Palme, K. (2006). Auxin in action: Signaling, transport and the control of plant growth and development. Nature Reviews Molecular Cell Biology, 7(11), 847-859.

Woodward, A. W., & Bartel, B. (2005). Auxin: Regulation, action, and interaction. Annals of Botany, 95(5), 707-735.

Yamaguchi, S. (2008). Gibberellin metabolism and its regulation. Annual Review of Plant Biology, 59, 225-251.

Zhu, J., & Lee, B. H. (2015). Genetic and biochemical approaches for dissecting the role of plant hormones in abiotic stress responses. Journal of Experimental Botany, 66(7), 1815-1825.

Zuo, J., & Li, J. (2014). Molecular dissection of the ethylene biosynthesis pathway. Plant Signaling & Behavior, 9(5), e27530.