乔治亚州大学的研究人员发现，操控一种硬木树种的一个特定的基因，不仅更易于将木材分解为燃料，而且能够显著加快树木的生长速度。
最近发表在《Biotechnology for
Biofuels》期刊上的一篇论文中，研究人员阐述了如何通过降低名为GAUT12.1的基因表达来降低木聚糖和果胶的水平，这是植物细胞壁的两个主要
成分，它们使树木具有耐酶性，而且从中提取的可发酵糖能够用于制造生物燃料。
“这项研究为我们提供了控制植物基因的重要线索，以及我们如何操控基因来为我们所用。”富兰克林文理学院生物化学与分子生物学教授，论文合著者
Debra Mohnen说。“难以分解复杂的植物细胞壁是生物燃料生产的瓶颈，这项发现为新技术的发展铺平了道路，使生产工艺更加经济可行。”
研究人员用美洲黑杨(又称东部杨木)这个树种来验证他们假设。他们与生物能源科学中心的同事一道，创造了11个转基因树木，这些树木的GAUT12.1水平降低了50%左右。
这个树种在生物燃料领域具有很大的吸引力，因为它们的生长周期短，能够在短期内产生出大量的生物质。
“我们的实验显示，我们创造的树木没有那么大的顽拗性，这意味着能易于从细胞壁中提取糖。”该研究论文的第一作者Ajaya Biswa说。“我们非常高兴地看到与同类型的野生树木相比，我们的这些树木生长速度更快。”
他们研究结果显示，与没有进行基因操控的树木相比，他们的树木高度增长了12%-52%，直径增大了12%-44%。
快速生长的植物会在较短的时间里产生更多的生物质，这使它们对种植者和生物燃料企业都具有非凡的吸引力，Mohnen说。
研究人员强调，这些只是初步的研究成果，他们和他们在生物能源研究中心的同事已经准备着手新的试验，测试他们的转基因树木在不同环境条件下的反应。
“我们已经从这个研究过程中学到了很多东西，我们有信心可以继续扩大和提高我们的研究成果，从而获得更好的生物质以及了解它们的产生过程，”Mohnen说。
英文原文：
Researchers create fast-growing trees that are easier to
turn into fuel
Researchers at the University of Georgia have discovered that
manipulation of a specific gene in a hardwood tree species not only
makes it easier to break down the wood into fuel, but also significantly
increases tree growth.
In a paper published recently in Biotechnology for Biofuels, the
researchers describe how decreasing the expression of a gene called
GAUT12.1 leads to a reduction in xylan and pectin, two major components
of plant cell walls that make them resistant to the enzymes and
chemicals used to extract the fermentable sugars used to create
biofuels.
"This research gives us important clues about the genes that control
plant structures and how we can manipulate them to our advantage," said
study co-author Debra Mohnen, a professor of biochemistry and molecular
biology in the Franklin College of Arts and Sciences. "The difficulty of
breaking down the complicated plant cell wall is a major obstacle to
the cost-effective production of biofuels, and this discovery may pave
the way for new techniques that make that process more economically
viable."
The researchers tested their hypothesis on a species of tree called
Populus deltoides, more commonly known as the eastern cottonwood.
Working together with colleagues in through the BioEnergy Science
Center, they created 11 transgenic trees in which GAUT12.1 was reduced
by approximately 50 percent.
This tree species is particularly attractive to the biofuel industry
because it grows relatively quickly and produces large quantities of
biomass in a short period of time.
"Our experiments show that the trees we created were less
recalcitrant, meaning that it would be easier to extract sugars from the
plant cell walls," said the study's lead author Ajaya Biswal, "But we
were particularly happy to see how quickly these trees grew compared to
what one would observe in with the wild type."
The plants they tested displayed between 12 and 52 percent increased
plant height and between 12 and 44 percent larger stem diameter when
compared to controls.
Faster growing plants would yield more biomass over a shorter period
of time, making them more attractive to both growers and the biofuel
industry, Mohnen said.
While the researchers emphasize that these are preliminary results,
they and their colleagues in BioEnergy Science Center are already
preparing new experiments that will test their transgenic trees in a
variety of different environments.
"We've already learned a lot from this process, but we are confident
that we can expand and improve on our research to achieve even better
biomass and understanding of how it is produced," said Mohnen.
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发表于 2015-3-23 03:22:16
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