Self-Incompatibility: Nature's Breeding Barrier Unveiling the Secrets of Self-Rejection in Plants – A review

Author: Roshin Mariam George and M.R. Bindu

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Abstract

Self-incompatibility (SI) is a sophisticated reproductive strategy employed by numerous flowering plants to prevent self-fertilization and promote outcrossing. This mechanism, crucial for maintaining genetic diversity and adaptability, involves intricate molecular interactions between pollen and pistil components, leading to the rejection of incompatible pollen. This review delves into the evolutionary history, classification, and molecular mechanisms underlying diverse SI systems. We explore the historical journey of understanding SI, from early observations of plant breeding patterns to the current molecular-level insights. We discuss the two primary types of SI: heteromorphic, characterized by distinct floral morphologies, and homomorphic, relying solely on genetic mechanisms. The molecular intricacies of single-locus and two-locus SI systems are examined, highlighting key genes and signaling pathways involved in pollen recognition and rejection. Furthermore, we explore the implications of SI for plant breeding, including its role in hybrid seed production and the development of desirable traits. Understanding and manipulating SI systems hold immense potential for enhancing crop yield, quality, and resilience in the face of changing environmental challenges

Keywords

Self incompatibility, GSI, SSI, Heterostyly, Molecular basis of SI

Conclusion

This comprehensive review explored the multifaceted phenomenon of self-incompatibility (SI) in flowering plants, tracing its historical understanding from early botanical observations to the latest molecular insights. While the concept of SI emerged from recognizing patterns of self-sterility in crops, it has evolved into a rich field encompassing genetics, molecular biology, and evolutionary ecology. The review highlighted the diversity of SI systems, ranging from the morphologically distinct heteromorphic systems like distyly and tristyly to the more cryptic homomorphic systems governed by complex genetic interactions at the S-locus. Although model systems in families like Solanaceae, Brassicaceae, and Papaveraceae have illuminated key molecular mechanisms of SI, vast gaps remain in our understanding of the diverse array of SI strategies employed across the plant kingdom. This incomplete knowledge represents a critical barrier to fully harnessing the power of SI for crop improvement. Future research should prioritize elucidating the molecular basis of SI in understudied plant families, particularly those with agricultural importance like Poaceae. Unraveling the evolutionary dynamics of SI, including the selective pressures driving its gain and loss, is crucial for understanding its broader role in plant diversification. Finally, the potential applications of SI in crop improvement are vast. By leveraging advancements in gene editing and genomic resources, we can engineer self-incompatible lines, facilitate hybrid breeding programs, and even manipulate SI to control seed production in fruits. A deeper understanding of SI will be paramount for maximizing agricultural productivity and ensuring global food security in the face of a changing climate

References

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How to cite this article

Roshin Mariam George and M.R. Bindu (2024). Self-Incompatibility: Nature's Breeding Barrier Unveiling the Secrets of Self-Rejection in Plants – A review. Biological Forum – An International Journal, 16(8): 262-274.