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.

在未来50年内，由于人口增加、人均作物使用量增加和许多环境问题等因素的综合作用，全球作物生产将面临相当大的压力。要大幅度提高全球种植面积的单产，需要付出相当大的努力，以经济和环境可持续的方式应对这一挑战。有效氮是作物生产的主要限制因素。氮肥现在是许多作物的最大投入成本，而发展中国家的农民负担不起化肥，导致产量下降。因此，更有效地利用可利用氮的作物品系将大大降低发达国家的成本，提高发展中国家的产量。此外，在农业中大量使用氮肥会造成重大的、不可逆转的环境破坏。因此，目前使用氮肥的做法是不可持续的，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。许多对多种作物的研究表明，氮肥的利用存在显著的遗传变异。尽管已经作出了重大努力并取得了重大进展，但对这些差异的遗传基础仍有许多需要了解的地方。