Overexpression of the maize Corngrass1 microRNA prevents flowering, improves digestibility, and increases starch content of switchgrass
Overexpression of the maize Corngrass1 microRNA prevents flowering, improves digestibility, and increases starch content of switchgrass
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DOI：
10.1073/pnas.1113971108
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发表时间：
2011-10-18
影响因子：
11.1
通讯作者：
Hake, Sarah
中科院分区：
文献类型：
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作者：
Chuck, George S.;Tobias, Christian;Hake, Sarah
由生物质作物开发的生物燃料有潜力满足我们运输燃料需求的很大一部分。然而，要实现这一潜力，有必要开发专门用作能源作物的改良植物种质。液态运输燃料可以从锁定在植物细胞壁内的糖类中制取。不幸的是，这些糖类本身对水解释放有抗性，因为它们包含在嵌入木质素的多糖中。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。玉米的Corngrass1（Cg1）基因编码一种微小RNA，它促进幼态细胞壁的特性和形态。为了验证幼态生物质作为潜在生物燃料原料具有更优品质这一假设，Cg1基因被转入其他几种植物中，包括生物能源作物柳枝稷（Panicum virgatum）。发现这类植物的淀粉含量最多可增加250%，导致在有或没有生物质预处理的糖化测定中葡萄糖释放量更高。此外，在温室和田间种植的植物中都观察到开花完全受到抑制。这些结果表明这种方法对于新生物燃料作物的驯化以及限制转基因流入本地植物物种都具有潜在的实用性。
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.