Plant Gene Expression Center/ US Department of Agriculture (USDA) and University of California (UC) Berkeley, Albany, CA 94710, USA.
Proc Natl Acad Sci U S A. 2011 Oct 18;108(42):17550-5. doi: 10.1073/pnas.1113971108. Epub 2011 Oct 10.
Biofuels developed from biomass crops have the potential to supply a significant portion of our transportation fuel needs. To achieve this potential, however, it will be necessary to develop improved plant germplasm specifically tailored to serve as energy crops. Liquid transportation fuel can be created from the sugars locked inside plant cell walls. Unfortunately, these sugars are inherently resistant to hydrolytic release because they are contained in polysaccharides embedded in lignin. Overcoming this obstacle is a major objective toward developing sustainable bioenergy crop plants. The maize Corngrass1 (Cg1) gene encodes a microRNA that promotes juvenile cell wall identities and morphology. To test the hypothesis that juvenile biomass has superior qualities as a potential biofuel feedstock, the Cg1 gene was transferred into several other plants, including the bioenergy crop Panicum virgatum (switchgrass). Such plants were found to have up to 250% more starch, resulting in higher glucose release from saccharification assays with or without biomass pretreatment. In addition, a complete inhibition of flowering was observed in both greenhouse and field grown plants. These results point to the potential utility of this approach, both for the domestication of new biofuel crops, and for the limitation of transgene flow into native plant species.
生物燃料可以从生物质作物中开发，有潜力为我们的交通燃料需求提供很大一部分供应。然而，为了实现这一潜力，将有必要开发专门改良的植物种质资源，以作为能源作物。液体运输燃料可以从植物细胞壁内锁定的糖中制造出来。不幸的是，由于这些糖被包含在木质素中的多糖所嵌入，因此它们天生就具有抵抗水解释放的能力。克服这一障碍是开发可持续生物能源作物的一个主要目标。玉米草 1 号（Cg1）基因编码一种 microRNA，可促进幼年细胞壁的身份和形态。为了验证这样一种假设，即幼年生物质具有作为潜在生物燃料原料的优越品质，将 Cg1 基因转入了其他几种植物，包括生物能源作物柳枝稷（芒草）。结果发现，这些植物的淀粉含量增加了 250%，从而使糖化分析中无论是否进行生物质预处理，葡萄糖的释放量都更高。此外，在温室和田间生长的植物中都观察到完全抑制了开花。这些结果表明了这种方法的潜在应用价值，既可以用于驯化新的生物燃料作物，也可以用于限制转基因流入本地植物物种。
