Molecular basis and evolutionary drivers of endosperm-based hybridization barriers

Abstract

The endosperm, a transient seed tissue, plays a pivotal role in supporting embryo growth and germination. This unique feature sets flowering plants apart from gymnosperms, marking an evolutionary innovation in the world of seed-bearing plants. Nevertheless, the importance of the endosperm extends beyond its role in providing nutrients to the developing embryo by acting as a versatile protector, preventing hybridization events between distinct species and between individuals with different ploidy. This phenomenon centers on growth and differentiation of the endosperm and the speed at which both processes unfold. Emerging studies underscore the important role played by type I MADS-box transcription factors, including the paternally expressed gene PHERES1. These factors, along with downstream signaling pathways involving auxin and abscisic acid, are instrumental in regulating endosperm development and, consequently, the establishment of hybridization barriers. Moreover, mutations in various epigenetic regulators mitigate these barriers, unveiling a complex interplay of pathways involved in their formation. In this review, we discuss the molecular underpinnings of endosperm-based hybridization barriers and their evolutionary drivers.

Celebrating the American Society of Plant Biologists centennial anniversary: A compendium of review articles in plant biology

“…Two reviews focus on aspects of plant reproduction. Zhong et al (2024) review major events in plant reproduction, including gametic differentiation to pollen-pistil interaction, fertilization, and early zygotic events in “From gametes to zygote: Mechanistic advances and emerging possibilities in plant reproduction.” In “Molecular basis and evolutionary drivers of endosperm-based hybridization barriers,” Bente and Köhler (2024) focus on the endosperm, which plays a key role in supporting embryo growth and germination in flowering plants. Rounding out the set in Plant Physiology are 2 reviews covering topics in cell biology and synthetic biology.…”

Celebrating the American Society of Plant Biologists centennial anniversary: A compendium of review articles in plant biology

“… Zhong et al (2024) review major events in plant reproduction, including gametic differentiation to pollen–pistil interaction, fertilization, and early zygotic events in From gametes to zygote: Mechanistic advances and emerging possibilities in plant reproduction . In Molecular basis and evolutionary drivers of endosperm-based hybridization barriers , Bente and Köhler (2024) focus on the endosperm, which plays a key role in supporting embryo growth and germination in flowering plants. Rounding out the set in Plant Physiology are 2 reviews covering topics in cell biology and synthetic biology.…”