• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Applying photosynthesis research to improvement of food crops >Status of options for improving photosynthetic capacity through promotion of Rubisco performance-Rubisco natural diversity and re-engineering, and other parts of C_3 pathways
【24h】

Status of options for improving photosynthetic capacity through promotion of Rubisco performance-Rubisco natural diversity and re-engineering, and other parts of C_3 pathways

机译：通过促进Rubisco表现提高光合作用能力的选择现状-Rubisco自然多样性和再工程以及C_3途径的其他部分

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Rubisco literature is very large. Our focus here is a critical assessment of current Rubisco research that most directly impacts on crop photosynthesis research, and that provides direction to strategies and technologies for implementing into crops to improve productivity. Recent comprehensive reviews are given by Spreitzer and Salvucci (2002), Parry et al. (2003), Portis and Parry (2007) and Andersson and Backlund (2008). Specific findings in this paper are as follows: 1. We have examined the implications of Rubisco's slow and non-selective catalysis and its highly conserved sequence and structure. No useful mutants have been reported in the published literature so far from targeted mutagenesis, directed evolution or gene shuffling methods. However, we conclude that there is no evidence that substantially better Rubiscos cannot have evolved or be engineered by mutation. 2. We have examined Rubisco's complex requirements for folding and assembly and other aspects of its regulation. We conclude that transforming foreign Rubiscos into crop plants is not promising. Thus, mutant Rubiscos should be carefully engineered so as not to introduce changes that hinder folding and assembly, post-translational modifications or binding of other proteins such as Rubisco activase. 3. These examinations highlight a major problem with the reliability of kinetic parameters reported in the Rubisco literature, which makes it difficult to compare results from different studies. This makes assessment of progress difficult and is impeding advancement in the field. 4. We have reviewed three types of indirect strategies for improving carbon assimilation in C_3 plants by enhancing Rubisco's capacity to carboxylate ribulose-l,5-bisphosphate (RuBP). These comprise improving CO_2 levels around Rubisco, increasing regeneration of RuBP by overexpression of the Calvin cycle enzyme sedoheptulose-1,7-bisphosphatase, and introducing more thermotolerant Rubisco activase. All three are novel engineering strategies that complement direct methods for improving Rubisco performance. 5. To illustrate how better understanding of Rubisco kinetics might be effectively used to guide Rubisco re-engineering or search for naturally variant Rubiscos, we undertook some simple 'what if?' simulations of carbon assimilation, using measured and hypothetical Rubisco kinetic parameters. We compared the performance of wheat and rice Rubiscos, and tobacco Rubisco with a mutant tobacco Rubisco with red-algal-like kinetics. We considered conditions mimicking drought and normal water-use conditions, with ambient atmospheric CO_2 concentration at levels currently and projected for 2050. These gedanken experiments reinforced the need for measurements of complete and reliable sets of kinetic parameters for crop and model plant species; the currently available data limit application of these convenient simulation tools to assess potential carbon-accumulation gains in-planta from mutant or other novel Rubiscos. 6. Our literature analysis provided strong empirical and theoretical evidence for the existence of variation in Rubisco properties within species of plants, and that this is correlated with environmental growing conditions, demonstrating a response to evolutionary selection. Recent evidence suggests greater scope for improved Rubiscos of higher plants from natural variation than previously thought. 7. Following these analyses, we reviewed two novel recent approaches to developing improved Rubiscos for crops: 1. identifying naturally occurring potentially superior Rubiscos from crop germplasm banks 2. re-engineering Rubiscos, which is patented technology developed at the Australian National University (ANU). The technique uses an in silico phylogenetic grafting method to predict mutants with improved kinetic properties. Both strategies have rational defined workflows that can be iterated to identify sources of germplasm more enriched with better Rubiscos or provide guidance on how to refine mutants to improve their activity. The diversity approach has the advantage of not requiring a genetic transformation but, as it has not yet been tested for a crop species, the gains in Rubisco performance obtainable are uncertain. Initial results from the mutant approach have already shown large gains in activity but a disadvantage of the approach is the requirement for chloroplast transformation, which has not been achieved in monocots such as cereals. 8. Our consideration of bottlenecks in chloroplast transformation technologies indicates several new possible solutions. Apart from the need for Rubisco transformation, the availability of efficient chloroplast transformation technologies would provide many benefits for other genes. Notable are higher biosafety if transgenes are contained within the plant plastid genome, and greater acceptance by regulatory bodies. Future crop development needs argue for an increased investment in these technologies. 9. We note a recent increase in patent applications related to Rubisco, Rubisco activase and respiratory bypass technologies, including the ANU technology. This suggests greater commercial interest from agbiotech companies in photosynthesis research for crop development.
机译：Rubisco的文献非常多。我们在这里的重点是对Rubisco当前研究的重要评估，该评估对农作物光合作用的研究最直接的影响，并为实施作物提高产量的策略和技术提供了方向。 Spreitzer和Salvucci（2002），Parry等人（2002年）给出了最新的综合评论。 （2003），波蒂斯（Portis）和帕里（Parry）（2007）以及安德森（Andersson）和Backlund（2008）。本文的具体发现如下：1.我们研究了Rubisco缓慢且非选择性催化的含义及其高度保守的序列和结构。迄今为止，除了靶向诱变，定向进化或基因改组方法外，在已发表的文献中没有报道有用的突变体。但是，我们得出结论，没有证据表明更好的Rubiscos不能通过突变进化或工程改造。 2.我们检查了Rubisco对折叠和组装的复杂要求以及其法规的其他方面。我们得出的结论是，将国外Rubiscos转变为作物植物没有希望。因此，应对突变型Rubiscos进行精心设计，以免引入阻碍折叠和组装，翻译后修饰或其他蛋白（例如Rubisco活化酶）结合的变化。 3.这些检查突出了Rubisco文献中报道的动力学参数可靠性的一个主要问题，这使得很难比较不同研究的结果。这使进度评估变得困难，并阻碍了该领域的进步。 4.我们综述了三种通过提高Rubisco羧化核糖-1,5-双磷酸核糖（RuBP）的能力来改善C_3植物碳同化的间接策略。这些包括提高Rubisco周围的CO_2水平，通过Calvin循环酶sedoheptulose-1,7-bisphosphatase的过表达增加RuBP的再生，以及引入更多的Rubisco耐热酶。这三种都是新颖的工程策略，可补充直接方法以提高Rubisco性能。 5.为了说明如何更好地理解Rubisco动力学，可以有效地指导Rubisco改造或寻找天然的Rubiscos，我们进行了一些简单的“假设假设”？使用测量的和假设的Rubisco动力学参数模拟碳同化。我们比较了小麦和大米Rubiscos的性能，以及烟草Rubisco和具有红藻样动力学的突变烟草Rubisco的性能。我们考虑了模仿干旱的条件和正常的用水条件，目前大气大气中的CO_2浓度达到了2050年的水平，并预计到2050年。这些实在的实验增加了对作物和模型植物物种完整而可靠的动力学参数集的需求。这些便利的仿真工具的当前可用数据限制了评估突变体或其他新型Rubiscos在植物体内潜在碳积累量的应用。 6.我们的文献分析为植物物种内Rubisco性质的变化提供了有力的经验和理论证据，并且这与环境生长条件相关，表明了对进化选择的反应。最近的证据表明，从自然变异中改良高等植物的Rubiscos的范围比以前认为的更大。 7.在进行了这些分析之后，我们回顾了开发作物改良Rubiscos的两种最新方法：1.从作物种质库中鉴定出天然存在的潜在优品Rubiscos。2.重新设计Rubiscos，这是澳大利亚国立大学（ANU）开发的专利技术。 ）。该技术使用计算机系统发育嫁接方法来预测具有改善的动力学特性的突变体。两种策略都有合理定义的工作流程，可以重复进行这些工作流程，以识别更富含更好Rubiscos的种质来源，或为如何精制突变体以提高其活性提供指导。多样性方法的优点是不需要进行遗传转化，但是由于尚未针对农作物进行过测试，因此不确定Rubisco性能的提高。突变方法的初步结果已经显示出活性的大幅提高，但是该方法的缺点是需要叶绿体转化，而在单子叶植物如谷物中尚未实现。 8.我们对叶绿体转化技术瓶颈的考虑表明了几种新的可能解决方案。除了需要Rubisco转化外，有效的叶绿体转化技术的可用性还将为其他基因带来许多好处。如果植物质体基因组中包含转基因，则具有更高的生物安全性，并获得监管机构的更大认可。未来作物的发展需求要求增加对这些技术的投资。 9.我们注意到，最近与Rubisco，Rubisco激活酶和呼吸旁路技术（包括ANU技术）有关的专利申请有所增加。这表明农业生物技术公司对作物生长的光合作用研究具有更大的商业兴趣。

著录项

  • 来源
  • 会议地点 Canberra(AU)
  • 作者

    Jill E. Gready; Babu Kannappan; Animesh Agrawa; Kenneth Street; David M. Stalker; Spencer M. Whitney;

  • 作者单位

    Computational Proteomics, John Curtin School of Medical Research, Australian National University, Canberra ACT 0200, Australia;

    Computational Proteomics, John Curtin School of Medical Research, Australian National University, Canberra ACT 0200, Australia;

    Computational Proteomics, John Curtin School of Medical Research, Australian National University, Canberra ACT 0200, Australia;

    Genetic Resources Section, ICARDA, PO Box 5466,Aleppo, Syrian Arab Republic;

    Applied Sciences, Science, Engineering Health, RMIT University, BundooraVic. 3083, Australia;

    Research School of Biology, Australian National University, Canberra ACT 0200, Australia;

  • 会议组织
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号