National Forestry and Grassland Administration, Beijing Key Open Laboratory On the Science and Technology of Bamboo and Rattan, Institute of Gene Science and Industrialization for Bamboo and Rattan Resources, International Center for Bamboo and Rattan, Beijing, 100102, China.
Jiangxi Academy of Forestry, Nanchang, 330013, China.
Plant Cell Rep. 2020 Jun;39(6):751-763. doi: 10.1007/s00299-020-02528-w. Epub 2020 Mar 9.
Twenty-three PeLACs have been identified in moso bamboo, overexpression of PeLAC10 increases the lignin content and confers drought and phenolic acid tolerance in transgenic Arabidopsis. Laccases (LACs) have multifunction involved in the processes of cell elongation, lignification and stress response in plants. However, the function of laccases in bamboo remain unclear. Here, a total of 23 laccase genes (PeLAC1-PeLAC23) were identified in moso bamboo (Phyllostachys edulis). The diverse gene structure and expression pattern of PeLACs suggested that their function should be spatiotemporal and complicated, which was supported by the expression profiles in different tissues of moso bamboo. Eighteen PeLACs were identified as the targets of ped-miR397. The putative ped-miR397-binding site in the coding region of PeLAC10 was further confirmed by RLM-5' RACE, indicating that PeLAC10 was regulated by ped-miR397 after transcription. With the increasing shoot height, the expression abundance of PeLAC10 was up-regulated and reached the maximum in 15 cm shoots, while that of ped-miR397 was relative lower and showed the minimum in 15 cm shoots. PeLAC10 was up-regulated obviously under both ABA (100 μmol L) and NaCl (400 mmol L) treatments, and it was down-regulated under the GA (100 μmol L) treatment. The transgenic Arabidopsis plants over-expressing PeLAC10 became slightly smaller and their petioles were shorter than those of Col-0. However, they had a stronger capacity in resistance to phenolic acids and drought besides higher lignin content in stems. These results indicated that overexpression of PeLAC10 was helpful to increase the content of lignin in transgenic Arabidopsis and improve the adaptability to phenolic acid and drought stresses.
23 个 PeLACs 在毛竹中被鉴定出来，过表达 PeLAC10 增加了木质素含量，并赋予转基因拟南芥抗旱和酚酸耐受性。漆酶（LACs）在植物的细胞伸长、木质化和应激反应过程中具有多种功能。然而，漆酶在竹子中的功能尚不清楚。在这里，总共鉴定出 23 个漆酶基因（PeLAC1-PeLAC23）在毛竹（Phyllostachys edulis）中。PeLACs 的多样化基因结构和表达模式表明，它们的功能应该是时空复杂的，这在毛竹不同组织的表达谱中得到了支持。18 个 PeLACs 被鉴定为 ped-miR397 的靶标。PeLAC10 编码区的推定 ped-miR397 结合位点通过 RLM-5' RACE 进一步得到证实，表明 PeLAC10 在转录后受到 ped-miR397 的调控。随着新梢高度的增加，PeLAC10 的表达丰度上调，在 15cm 新梢中达到最大值，而 ped-miR397 的表达丰度相对较低，在 15cm 新梢中达到最小值。ABA（100μmol·L-1）和 NaCl（400mmol·L-1）处理下 PeLAC10 明显上调，GA（100μmol·L-1）处理下下调。过表达 PeLAC10 的转基因拟南芥植物略小，叶柄比 Col-0 短。然而，它们在酚酸和干旱胁迫下具有更强的抗性能力，并且茎木质素含量更高。这些结果表明，过表达 PeLAC10 有助于增加转基因拟南芥木质素的含量，提高对酚酸和干旱胁迫的适应性。
