Donald Danforth Plant Science Center, 975 N. Warson RD, St. Louis, MO 63132, USA.
Plant Physiol Biochem. 2011 Jan;49(1):103-9. doi: 10.1016/j.plaphy.2010.10.004. Epub 2010 Oct 27.
Many bioenergy feedstocks are not easily converted to fermentable substrates due to of high proportions of lignin, which impedes the degradation of cell wall polysaccharides to fermentable sugars. To reduce lignin levels during plant growth, we generated transgenic Arabidopsis plants that contain a gene that confers inducible silencing of both 4CL1 and 4CL2 genes; these genes play a compensatory role in normal development of Arabidopsis, including in mechanisms of stem growth. To alter lignocellulose composition at specific times in plant development, genes were silenced at bolting, immature stages (5-7 cm high), and intermediate stages (10-15 cm high). The stems of induced plants at all stages of development exhibited increased cellulose content and reduced amounts of total lignin when compared with non-induced stems. Furthermore, treating plants at advanced stages of development (the immature and intermediate stages) had little impact on plant growth and development while plants treated at the bolting stage exhibited modest abnormal development. Our results suggest that it is possible to alter lignocellulose composition in plants without negative effects on plant growth.
许多生物能源原料由于木质素含量高而不易转化为可发酵的基质，木质素阻碍了细胞壁多糖降解为可发酵糖。为了在植物生长过程中降低木质素水平，我们生成了转基因拟南芥植物，这些植物含有一个基因，该基因可诱导沉默 4CL1 和 4CL2 基因；这些基因在拟南芥的正常发育中发挥着代偿作用，包括在茎生长的机制中。为了在植物发育的特定时间改变木质纤维素的组成，在抽薹、未成熟阶段（5-7 厘米高）和中间阶段（10-15 厘米高）沉默基因。与未诱导的茎相比，处于发育所有阶段的诱导植物的茎表现出纤维素含量增加和总木质素含量减少。此外，在植物发育的后期（未成熟和中间阶段）处理植物对植物的生长和发育几乎没有影响，而在抽薹阶段处理的植物表现出适度的异常发育。我们的结果表明，有可能在不影响植物生长的情况下改变植物中的木质纤维素组成。
