Summary Ultraviolet (UV) radiation influences development and genome stability in organisms; however, its impact on meiosis, a special cell division essential for the delivery of genetic information across generations in eukaryotes, has not yet been elucidated. In this study, by performing cytogenetic studies, we reported that UV radiation does not damage meiotic chromosome integrity but attenuates centromere‐mediated chromosome stability and induces unreduced gametes in Arabidopsis thaliana. We showed that functional centromere‐specific histone 3 (CENH3) is required for obligate crossover formation and plays a role in the protection of sister chromatid cohesion under UV stress. Moreover, we found that UV specifically alters the orientation and organization of spindles and phragmoplasts at meiosis II, resulting in meiotic restitution and unreduced gametes. We determined that UV‐induced meiotic restitution does not rely on the UV Resistance Locus8‐mediated UV perception and the Tapetal Development and Function1‐ and Aborted Microspores‐dependent tapetum development, but possibly occurs via altered JASON function and downregulated Parallel Spindle1. This study provides evidence that UV radiation influences meiotic genome stability and gametophytic ploidy consistency in flowering plants.

中文翻译：

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紫外线减弱着丝粒介导的减数分裂基因组稳定性并改变开花植物配子体倍性的一致性


摘要 紫外线 (UV) 辐射影响生物体的发育和基因组稳定性；然而，它对减数分裂的影响尚未阐明，减数分裂是真核生物中跨代传递遗传信息所必需的特殊细胞分裂。在这项研究中，通过进行细胞遗传学研究，我们发现紫外线辐射不会损害减数分裂染色体的完整性，但会减弱着丝粒介导的染色体稳定性并诱导拟南芥配子未减少。我们发现，功能性着丝粒特异性组蛋白 3 (CENH3) 是专性交叉形成所必需的，并且在紫外线胁迫下保护姐妹染色单体的凝聚力中发挥作用。此外，我们发现紫外线特异性地改变减数分裂II时纺锤体和成膜体的方向和组织，导致减数分裂恢复和未减少的配子。我们确定，紫外线诱导的减数分裂恢复并不依赖于紫外线抗性位点8介导的紫外线感知以及绒毡层发育和功能1以及中止的小孢子依赖的绒毡层发育，但可能通过改变JASON功能和下调平行纺锤体1来发生。这项研究提供了紫外线辐射影响开花植物减数分裂基因组稳定性和配子体倍性一致性的证据。