Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
Plant Physiol. 2024 Jul 31;195(4):2579-2595. doi: 10.1093/plphys/kiae165.
MutL homolog 1 (MLH1), a member of the MutL homolog family, is required for normal recombination in most organisms. However, its role in soybean (Glycine max) remains unclear to date. Here, we characterized the Glycine max female and male sterility 1 (Gmfms1) mutation that reduces pollen grain viability and increases embryo sac abortion in soybean. Map-based cloning revealed that the causal gene of Gmfms1 is Glycine max MutL homolog 1 (GmMLH1), and CRISPR/Cas9 knockout approach further validated that disruption of GmMLH1 confers the female-male sterility phenotype in soybean. Loss of GmMLH1 function disrupted bivalent formation, leading to univalent mis-segregation during meiosis and ultimately to female-male sterility. The Gmmlh1 mutant showed about a 78.16% decrease in meiotic crossover frequency compared to the wild type. The residual chiasmata followed a Poisson distribution, suggesting that interference-sensitive crossover formation was affected in the Gmmlh1 mutant. Furthermore, GmMLH1 could interact with GmMLH3A and GmMLH3B both in vivo and in vitro. Overall, our work demonstrates that GmMLH1 participates in interference-sensitive crossover formation in soybean, and provides additional information about the conserved functions of MLH1 across plant species.
MutL 同源物 1(MLH1)是 MutL 同源物家族的成员,在大多数生物体中,它是正常重组所必需的。然而,其在大豆(Glycine max)中的作用至今仍不清楚。在这里,我们对降低花粉粒活力并增加大豆胚囊败育的 Glycine max 雌性和雄性不育 1(Gmfms1)突变进行了表征。基于图谱的克隆表明,Gmfms1 的致病基因是 Glycine max MutL 同源物 1(GmMLH1),CRISPR/Cas9 敲除方法进一步验证了 GmMLH1 的破坏赋予了大豆的雌性-雄性不育表型。GmMLH1 功能的丧失破坏了二价体的形成,导致减数分裂过程中的单价体错误分离,最终导致雌性-雄性不育。与野生型相比,Gmmlh1 突变体的减数分裂交叉频率降低了约 78.16%。残留的交叉点遵循泊松分布,表明 Gmmlh1 突变体中的干扰敏感交叉形成受到了影响。此外,GmMLH1 可以在体内和体外与 GmMLH3A 和 GmMLH3B 相互作用。总的来说,我们的工作表明 GmMLH1 参与了大豆中干扰敏感交叉形成,为 MLH1 在植物物种中的保守功能提供了更多信息。