Herridge Rowan, Brownfield Lynette, Macknight Richard
Department of Biochemistry, University of Otago, Dunedin, New Zealand.
Front Plant Sci. 2021 Mar 5;12:640324. doi: 10.3389/fpls.2021.640324. eCollection 2021.
Perennial ryegrass () is a temperate grass species commonly used as pasture for livestock. Flowering (heading) of ryegrass impacts metabolizable energy content and seed yield, therefore this trait is important for both farmers and seed producers. In related grass species, the genes (-) have been largely implicated in the determination of vernalization response and are responsible for much of the intra-species variation in this trait. Many other important flowering-time regulators have been cataloged in the model grass however, in several cases, such as , their ryegrass homologs have not been well-characterized. Here, ryegrass homologs of important flowering time genes from were identified through available synteny data and sequence similarity. Phylogenetic analysis of and genes was performed to elucidate these families further. The expression patterns of these genes were assessed during vernalization. This confirmed the key roles played by and in the promotion of flowering. Furthermore, two orthologs of identified here, as well as an ortholog of , were expressed prior to vernalization, and were repressed in flowering plants, suggesting a role in floral repression. Significant variability in expression of these flowering pathway genes in diverse genotypes was detected and may underlie variation in flowering time and vernalization response.
多年生黑麦草（Lolium perenne）是一种温带草种，常用于作为家畜的牧草。黑麦草的开花（抽穗）会影响可代谢能量含量和种子产量，因此这一性状对农民和种子生产者都很重要。在相关草种中，VRN 基因（VERNALIZATION1）在很大程度上与春化反应的决定有关，并负责该性状在种内的大部分变异。在模式草种中已经列出了许多其他重要的开花时间调节因子，然而，在一些情况下，如 Brachypodium distachyon，它们的黑麦草同源物尚未得到很好的表征。在这里，通过可用的共线性数据和序列相似性鉴定了来自 Brachypodium distachyon 的重要开花时间基因的黑麦草同源物。对 VRN 和 FLC 基因进行了系统发育分析，以进一步阐明这些家族。在春化过程中评估了这些基因的表达模式。这证实了 VRN 和 FLC 在促进开花中所起的关键作用。此外，这里鉴定的两个 VRN1 直系同源物以及一个 FLC 直系同源物在春化之前表达，并在开花植物中受到抑制，表明它们在花抑制中起作用。检测到这些开花途径基因在不同基因型中的表达存在显著差异，这可能是开花时间和春化反应变异的基础。
