Department of Wood Science & Engineering, Oregon State University, Corvallis, OR 97330, USA.
USDA Forest Service, Pacific Northwest Research Station, 3200 Jefferson Way, Corvallis, OR 97330, USA.
New Phytol. 2011 Mar;189(4):1096-1109. doi: 10.1111/j.1469-8137.2010.03572.x. Epub 2010 Dec 15.
• Reduced lignin content in perennial crops has been sought as a means to improve biomass processability for paper and biofuels production, but it is unclear how this could affect wood properties and tree form. • Here, we studied a nontransgenic control and 14 transgenic events containing an antisense 4-coumarate:coenzyme A ligase (4CL) to discern the consequences of lignin reduction in poplar (Populus sp.). During the second year of growth, trees were grown either free-standing in a field trial or affixed to stakes in a glasshouse. • Reductions in lignin of up to 40% gave comparable losses in wood strength and stiffness. This occurred despite the fact that low-lignin trees had a similar wood density and up to three-fold more tension wood. In free-standing and staked trees, the control line had twice the height for a given diameter as did low-lignin trees. Staked trees had twice the height for a given diameter as free-standing trees in the field, but did not differ in wood stiffness. • Variation in tree morphogenesis appears to be governed by lignin x environment interactions mediated by stresses exerted on developing cells. Therefore our results underline the importance of field studies for assessing the performance of transgenic trees with modified wood properties.
• 人们一直致力于降低多年生作物的木质素含量，以期提高其生物量的可加工性，使其更适合用于造纸和生物燃料生产，但目前尚不清楚这将如何影响木材特性和树木形态。• 在这里，我们研究了一个非转基因对照和 14 个含有反义 4-香豆酸：辅酶 A 连接酶（4CL）的转基因事件，以探究杨树（Populus sp.）木质素减少的后果。在生长的第二年，树木在田间试验中要么自由生长，要么固定在温室中的桩上。• 木质素减少高达 40%，导致木材强度和刚性相当大的损失。尽管低木质素树木的木材密度相似，而且具有多达三倍的张木，但仍会出现这种情况。在自由生长和固定生长的树木中，对照系的高度是给定直径的两倍，而低木质素树木的高度也是给定直径的两倍。在田间，固定生长的树木的高度是自由生长树木的两倍，但木材硬度没有差异。• 树木形态发生的变化似乎受木质素 x 环境相互作用的控制，这些相互作用是由施加在发育细胞上的压力介导的。因此，我们的结果强调了进行田间研究以评估具有改良木材特性的转基因树木性能的重要性。
