State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China.
Int J Mol Sci. 2022 Dec 27;24(1):427. doi: 10.3390/ijms24010427.
Fasciclin-like arabinogalactan proteins (FLAs) play an important role in plant development and adaptation to the environment. However, the roles of FLAs in wood formation remain poorly understood. Here, we identified a total of 50 genes in poplar. They were classified into four groups: A to D, among which group A was the largest group with 28 members clustered into four branches. Most of group A were dominantly expressed in developing xylem based on microarray and RT-qPCR data. The roles of and in group A were investigated via the Cas9/gRNA-induced mutation lines. Loss of and increased stem length and diameter in double mutants, but not in or single mutants. Further, our findings indicated that the mutants enlarged the cell size of xylem fibers and vessels, suggesting a negative modulation in stem xylem cell size. In addition, wood lignin content in the mutants was increased by nearly 9%, and the lignin biosynthesis-related genes were significantly up-regulated in the mutants, in agreement with the increase in wood lignin content. Overall, Cas9/gRNA-mediated mutations in and reveal redundant roles in modulating wood cell size and secondary cell wall (SCW) synthesis in poplar.
纤维连接蛋白样阿拉伯半乳聚糖蛋白 (FLAs) 在植物发育和适应环境中发挥着重要作用。然而，FLAs 在木材形成中的作用仍知之甚少。在这里，我们在杨树中总共鉴定出 50 个基因。它们被分为四个组：A 到 D，其中 A 组是最大的组，有 28 个成员聚类成四个分支。大多数 A 组根据微阵列和 RT-qPCR 数据在发育中的木质部中表达。通过 Cas9/gRNA 诱导的突变系研究了 A 组中的 和 的作用。 和 的双突变体增加了茎的长度和直径，但 和 单突变体没有增加。此外，我们的研究结果表明，突变体增大了木质部纤维和导管的细胞大小，表明对茎木质部细胞大小的负调控。此外，木质素含量在 突变体中增加了近 9%，木质素生物合成相关基因在 突变体中显著上调，与木质素含量的增加一致。总的来说，Cas9/gRNA 介导的 和 突变揭示了在调节杨树木质部细胞大小和次生细胞壁 (SCW) 合成方面的冗余作用。
