Wu R L, Remington D L, Mackay J J, McKeand S E, O'Malley D M
Forest Biotechnology Group and Department of Forestry, North Carolina State University, NC 27695, Raleigh, USA, US,
Theor Appl Genet. 1999 Aug;99(3-4):705-10. doi: 10.1007/s001220051287.
Cinnamyl alcohol dehydrogenase (CAD, E.C. 1.1.1.195) is a monolignol biosynthetic enzyme that catalyzes the final step of lignin subunit biosynthesis in higher plants. Recently, a mutant allele of the cad gene, cad-n1, encoding for the CAD enzyme, was discovered in loblolly pine. By reducing the expression of the cad gene, this mutant has a decreased lignin content and major changes in the lignin composition in wood. In this study, we found that the substitution of a wild-type allele by cad-n1 was associated with a significant effect on 2nd-year shoot elongation in a half-sib family of loblolly pine (designated family 7-1037). The average effect of cad-n1 appeared to increase with tree growth and was greater for stem radial growth than height growth. An increase of 14.1% in de-barked volume in year 4 was associated with cad-n1. Co-segregation analysis indicated that the cad locus itself might represent a gene that governs stem growth in pine. The significance of the mutation cad-n1 for tree growth and wood processing is discussed.
肉桂醇脱氢酶（CAD，E.C. 1.1.1.195）是一种单木质醇生物合成酶，催化高等植物中木质素亚基生物合成的最后一步。最近，在火炬松中发现了编码CAD酶的cad基因的一个突变等位基因cad-n1。通过降低cad基因的表达，该突变体的木质素含量降低，木材中木质素组成发生重大变化。在本研究中，我们发现用cad-n1取代野生型等位基因对火炬松一个半同胞家系（命名为家系7-1037）的二年生嫩枝伸长有显著影响。cad-n1的平均效应似乎随着树木生长而增加，对茎径向生长的影响大于对树高生长的影响。第4年去皮材积增加14.1%与cad-n1有关。共分离分析表明，cad位点本身可能代表一个控制松树茎生长的基因。讨论了cad-n1突变对树木生长和木材加工的意义。
