State Key Laboratory of Tree Genetics and Breeding, Research Institute of Wood Industry, Chinese Academy of Forestry, 100091, Beijing, P.R. China.
State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, 100091, Beijing, P.R. China.
Sci Rep. 2018 Jul 12;8(1):10508. doi: 10.1038/s41598-018-28675-5.
This research focused on the cell wall structure and its mechanical properties of down-regulated Coumaroyl shikimate 3-hydroxylase (C3H) transgenic poplar and down-regulated hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) transgenic poplar (Populus alba × P. glandulosa cv '84 k'). The wood samples with respect to microstructure, the longitudinal elastic modulus (MOE) and hardness of wood fiber secondary cell wall were investigated. The results show that the lignin contents in the two transgenic poplar woods were lower than non-modified wood. The C3H transgenic poplar and HCT transgenic poplar have more than 18.5% and 16.1% cellulose crystalline regions than non-modified poplar respectively. The diameter of the fiber cell and the vessel element of transgenic poplars are smaller. Double radial vessel cell wall thicknesses of both transgenic poplars were smaller than non-modified poplar. Cell wall ratios for the transgenic poplar were higher than non-modified poplar and cell wall density was significantly lower in both C3H and HCT transgenic poplar. The cell wall MOEs of C3H and HCT transgenic poplar was 5.8% and 7.0% higher than non-modified poplar. HCT can be more effective than C3H to modify the trees by considerably increasing mechanical properties of the cell wall.
本研究聚焦于下调肉桂酰莽草酸 3-羟化酶（C3H）转基因杨树和下调对羟基肉桂酰辅酶 A：莽草酸对羟基肉桂酰转移酶（HCT）转基因杨树（Populus alba × P. glandulosa cv '84 k'）的细胞壁结构及其力学性能。对木材样本的微观结构、纵向弹性模量（MOE）和木材纤维次生细胞壁硬度进行了研究。结果表明，两种转基因杨树木材的木质素含量均低于未修饰木材。C3H 转基因杨树和 HCT 转基因杨树的纤维素结晶区分别比未修饰的杨树多 18.5%和 16.1%。转基因杨树的纤维细胞和导管分子的直径较小。两种转基因杨树的双径向导管细胞壁厚度均小于未修饰的杨树。转基因杨树的细胞壁比率高于未修饰的杨树，且 C3H 和 HCT 转基因杨树的细胞壁密度显著降低。C3H 和 HCT 转基因杨树的细胞壁 MOE 比未修饰的杨树分别高出 5.8%和 7.0%。HCT 可比 C3H 更有效地修饰树木，显著提高细胞壁的机械性能。
