Department of Wood Science, University of British Columbia, Vancouver, British Columbia, Canada.
Appl Environ Microbiol. 2013 Apr;79(8):2560-71. doi: 10.1128/AEM.03182-12. Epub 2013 Feb 8.
In order to elucidate the effects of lignin composition on the resistance of wood to degradation by decay fungi, wood specimens from two transgenic poplar lines expressing an Arabidopsis gene encoding ferulate 5-hydroxylase (F5H) driven by the cinnimate-4-hydroxylase promoter (C4H::F5H) that increased syringyl/guaiacyl (S/G) monolignol ratios relative to those in the untransformed control wood were incubated with six different wood decay fungi. Alterations in wood weight and chemical composition were monitored over the incubation period. The results showed that transgenic poplar lines extremely rich in syringyl lignin exhibited a drastically improved resistance to degradation by all decay fungi evaluated. Lignin monomer composition and its distribution among cell types and within different cell layers were the sole wood chemistry parameters determining wood durability. Since transgenic poplars with exceedingly high syringyl contents were recalcitrant to degradation, where wood durability is a critical factor, these genotypes may offer improved performance.
为了阐明木质素组成对木材抗腐朽真菌降解的影响，我们用 6 种不同的木材腐朽真菌对 2 种表达来自拟南芥的编码 5-羟松柏醇合成酶（F5H）基因的转基因杨树品系（由肉桂醇 4-羟化酶启动子（C4H::F5H）驱动）的木材标本进行了培养，该基因的表达增加了相对于未转化对照木材的愈创木基/丁香基（S/G）单体木质素的比例。在培养期间监测了木材重量和化学组成的变化。结果表明，富含愈创木基木质素的转基因杨树品系对所有评价的腐朽真菌的降解表现出了极大的抗性改善。木质素单体组成及其在细胞类型之间和不同细胞层内的分布是唯一决定木材耐久性的木材化学参数。由于富含愈创木基的转基因杨树对降解具有很强的抗逆性，而木材耐久性是一个关键因素，这些基因型可能提供更好的性能。
