Aguirre Manuel, Loperfido Domenico, Ezquer Ignacio
Translational Plant & Microbial Biology, Institute of Environmental Biology, Utrecht University, Padualaan 8, Utrecht, 3584CH, The Netherlands.
Dipartimento Di BioScienze, Università Degli Studi Di Milano, Via Celoria 26, Milano, 20133, Italy.
BMC Plant Biol. 2025 Jul 15;25(1):913. doi: 10.1186/s12870-025-06844-9.
Plant evolution has been greatly influenced by polyploidization phenomena. Polyploid plants yield more and are more resistant to unfavorable environments than their diploid relatives. The triploid block, a postzygotic barrier that causes failure of endosperm development and thus seed arrest, often prevents polyploid breeding. Alterations in the parental dose in interploidy crosses alter endosperm development by changing the correct maternal: paternal ratio (2m:1p) that this tissue requires to properly fulfill its proliferation and cellularization. After many years of research, the study of epigenetic regulation of gene expression during seed development has greatly increased our understanding of the triploid block. In plants, epigenetic regulation of genes has been shown to play a critical role in transcriptional control. This may be important for identifying novel and unexpected epigenetic mechanisms in the plant genome. Recent advances in understanding how epigenetic mechanisms control the expression of imprinted genes in seeds have contributed to understanding how different seed compartments interact at fertilization for successful seed formation. We here also review the potential role of maternally derived sporophytic tissues (seed coat) in the establishment of the triploid block. We also present a data analysis that includes spatiotemporal expression patterns of key genes involved in controlling hybridization barriers. This review provides an overview of the triploid block in plants, discussing how understanding its epigenetic regulation could offer new strategies to overcome hybridization barriers. We explore how these insights may enhance crop productivity and resilience.
植物进化受到多倍体化现象的极大影响。多倍体植物比其二倍体亲缘植物产量更高，且对不利环境的耐受性更强。三倍体障碍是一种合子后障碍，会导致胚乳发育失败，进而使种子发育停滞，常常阻碍多倍体育种。倍性间杂交中亲本剂量的改变会通过改变该组织正常完成增殖和细胞化所需的正确母本：父本比例（2m:1p）来改变胚乳发育。经过多年研究，对种子发育过程中基因表达的表观遗传调控的研究极大地增进了我们对三倍体障碍的理解。在植物中，基因的表观遗传调控已被证明在转录控制中起关键作用。这对于识别植物基因组中新颖且意想不到的表观遗传机制可能很重要。在理解表观遗传机制如何控制种子中印迹基因的表达方面的最新进展，有助于理解不同种子部分在受精时如何相互作用以成功形成种子。我们在此还综述了母本来源的孢子体组织（种皮）在三倍体障碍形成中的潜在作用。我们还展示了一项数据分析，其中包括参与控制杂交障碍的关键基因的时空表达模式。本综述概述了植物中的三倍体障碍，讨论了理解其表观遗传调控如何能提供克服杂交障碍的新策略。我们探讨了这些见解如何可能提高作物生产力和恢复力。
