Genetic and Genomic Analysis of Plant Response to Limiting Nutrient Environments

植物对限制营养环境的反应的遗传和基因组分析

• 批准号: RGPIN-2014-06381
• 负责人: Rothstein, Steven
• 金额: $ 2.91万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=612189
• 关键词: Genetic; Genomic; Analysis; Plant; Response

Within the next 50 years, considerable stress will be placed on worldwide crop production from a combination of factors including increased human population, an increase in the crops used per person and many environmental issues. To significantly increase yields per area planted worldwide will require considerable effort to meet this challenge in an economically and environmentally sustainable fashion. Available nitrogen is a major limiting factor in crop production. Nitrogen fertilizer is now the single largest input cost for many crops and farmers in developing countries cannot afford fertilizer, leading to lower yields. Therefore crop lines that utilize available nitrogen more efficiently would significantly reduce costs in the developed world and increase yields in the developing world. In addition, use of large amounts of N fertilizer in agriculture causes significant and irreversible environmental damage. Thus, current practices of nitrogen fertilizer use are unsustainable and, given the need for enhanced crop yields over the next half-century, increasing nitrogen application is clearly problematic. Many studies have been done on a wide variety of crops demonstrating that there is significant genetic variability in utilizing nitrogen fertilizer. Although significant efforts and progress have been made, there are still much to be understood on the genetic basis of these differences. It is crucial to understand the underlying role of different genes on nitrogen acquisition and use in order to develop crops that use nitrogen more efficiently. We have done considerable research on how plants respond to conditions where the nitrogen nutrient limits plant growth in order to understand which genes are important for this response. This proposal places primary emphasis on how metabolic pathways are regulated that might affect the plant response to nitrogen stress adaptation as well as how they remobilize the acquired organic nitrogen for seed production. The focus will be on two basic processes. First, we will look at a set of genes that regulate chlorophyll amounts particularly under low nitrogen conditions. We have demonstrated that these regulatory genes modulate the number of chloroplasts present as well as the amount of chlorophyll and starch. Changing the activity of this gene can lead to changes in all of these. Second, we will study some key aspects of biomass formation and nitrogen remobilization. The amount of biomass produced and the percentage of the nutrients from this biomass that ends up in the seed are the key determinants of crop yield. Finally, nitrogen limitation is only one of the many types of stress that crop plants typically endure under field conditions. The proposed studies will also include a delineation of responses to multiple nutrient/stress conditions like drought and planting density stress, using genomic methodologies and bioinformatics analyses. By delineating how plants respond to different combinations of stress, we will gain understanding of the combinatorial nature of how these affect plant growth and development. From earlier studies, we know that this response is not additive and that each combination has some unique elements. Thus, we hope to develop more sophisticated indicators of crop response to these important conditions that significantly affect crop yield.

未来 50 年内，人口增加、人均农作物用量增加以及许多环境问题等因素综合作用将给全球农作物生产带来相当大的压力。要显着提高全球种植面积的产量，需要付出巨大的努力，以经济和环境可持续的方式应对这一挑战。速效氮是作物生产的主要限制因素。氮肥现在是许多农作物最大的单一投入成本，发展中国家的农民买不起肥料，导致产量下降。因此，更有效地利用可用氮的作物品种将显着降低发达国家的成本并提高发展中国家的产量。此外，农业中大量使用氮肥会造成严重且不可逆转的环境破坏。因此，目前氮肥的使用做法是不可持续的，而且考虑到未来半个世纪提高作物产量的需要，增加氮肥的施用显然是有问题的。对多种作物进行的许多研究表明，氮肥的利用存在显着的遗传变异。尽管已经做出了重大努力并取得了进展，但这些差异的遗传基础仍有很多有待了解。 为了开发更有效地利用氮的作物，了解不同基因对氮获取和利用的潜在作用至关重要。我们对植物如何应对氮养分限制植物生长的条件进行了大量研究，以便了解哪些基因对于这种反应很重要。该提案主要强调如何调节可能影响植物对氮胁迫适应的反应的代谢途径，以及它们如何重新利用获得的有机氮用于种子生产。重点将放在两个基本流程上。首先，我们将研究一组调节叶绿素含量的基因，特别是在低氮条件下。我们已经证明这些调节基因调节叶绿体的数量以及叶绿素和淀粉的量。改变该基因的活性可以导致所有这些变化。其次，我们将研究生物质形成和氮再利用的一些关键方面。产生的生物量以及最终进入种子的生物量中的养分百分比是作物产量的关键决定因素。最后，氮限制只是作物在田间条件下通常承受的多种胁迫之一。拟议的研究还将包括使用基因组方法和生物信息学分析来描述对多种营养/胁迫条件（如干旱和种植密度胁迫）的反应。通过描述植物如何响应不同的胁迫组合，我们将了解这些胁迫如何影响植物生长和发育的组合性质。从早期的研究中，我们知道这种反应不是相加的，并且每种组合都有一些独特的元素。因此，我们希望开发更复杂的指标来衡量作物对这些显着影响作物产量的重要条件的反应。