Improving germination performance through a mechanistic understanding of seed priming

通过对种子引发的机械理解提高发芽性能

• 批准号: BB/S002081/1
• 负责人: Christopher West
• 金额: $ 56.79万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FS002081%2F1
• 关键词: Improving; germination; performance; through; mechanistic

The project will address the important agricultural issue of improving seed germination, in particular in seeds that are pre-treated to enhance germination processes. Seeds underpin sustainable agriculture and food security, providing the majority of global food principally as cereals and legumes. Seeds also play essential roles in crop propagation, and optimal yields require high vigour seed lots that provide rapid, uniform germination and seedling establishment that is tolerant of stress conditions. Germination and seedling establishment are routinely improved in commercial species by pre-treatment of seeds prior to germination. This process, termed priming, involves controlled hydration to activate pre-germinative processes without completion of germination. However, the molecular basis of priming, and the associated loss of seed longevity in primed seeds, is not well understood to-date, but cellular repair processes are likely to have key roles.In this project, we will uncover the molecular mechanisms which confer vigour enhancement in priming, and establish the genetic basis for the associated loss of seed longevity. This builds on our recent discovery that the mechanisms that mediate responses to DNA damage in plants control germination. In dry seeds there is a steady accumulation of background DNA damage which is exacerbated by adverse conditions during seed maturation, storage and germination. This leads to extremely high levels of genome stress experienced by the embryo upon seed rehydration. High levels of DNA repair activity are required early in germination to reverse this damage before growth resumes, as failure in repair processes results in severe mutagenesis of genetic material, impaired development and ultimately death of the plant. Sensing of DNA damage leads to rapid activation of cellular signalling programmes early in germination that function to delay germination, allowing extended time for repair, or activate cell death. As priming functions to reverse this delay to germination, we hypothesise a central role for DNA repair and damage signalling processes in the priming mechanism. Here we will use genetic, biochemical and high throughput analytical approaches to reveal the molecular link between genome integrity and priming, establishing the mechanistic basis of seed priming for the enhancement of seed germination.Primed seeds display reduced storability, resulting in substantial yield economic losses for the seed industry. The underlying causes of this reduced longevity is unknown. However, we recently identified that seeds defective in the repair of chromosomal breaks display highly reduced longevity after priming. This important new result reveals a novel link between increased DNA damage in primed seeds with the accelerated loss of germination potential. We will build on these results to reveal the molecular basis for the reduced longevity of primed seeds, identifying the requirement for specific repair activities that mitigate reduced shelf-life post-priming. Furthermore, identifying the signalling responses associated with reduced longevity provides a powerful approach to reveal the underlying cellular causes of the short lifespan of primed seeds.The ultimate aim of this project is to develop novel lines of plants with improved longevity after priming through modulating the activity of these DNA repair factors. We will test the potential of key factors to genetically improve the resilience of seed germination in Arabidopsis and Brassica oleracea, a crop species important to UK agriculture. These approaches will address the long-standing problem that seeds of many vegetable species suffer from poor germination and establishment after storage, resulting in reduced crop yields. Taken together, the project will enable the application of technologies based on our knowledge of plant stress responses to deliver high quality seeds and support sustainable agriculture.

该项目将解决改善种子发芽的重要农业问题，特别是在预先处理以增强发芽过程的种子中。种子是可持续农业和粮食安全的基础，这些种子主要作为谷物和豆类提供了大多数全球粮食。种子在作物繁殖中也起着重要的作用，最佳产量需要高活力种子批次，这些种子可提供快速，均匀的发芽和幼苗的建立，这些既容忍应激条件。通过在发芽之前的种子进行预处理，通常会改善发芽和幼苗的建立。该过程称为启动，涉及受控的水合，以激活终粒前过程，而无需完成发芽。然而，启动种子中启动的分子基础以及种子寿命的相关损失尚不很好地理解，但是细胞修复过程很可能具有关键作用。在该项目中，我们将发现赋予分子机制，这些机制赋予了分子机制启动的活力增强，并建立相关种子寿命丧失的遗传基础。这是基于我们最近发现的，即介导对植物中DNA损伤的反应的机制控制发芽。在干燥的种子中，背景DNA损伤稳定地积累，在种子成熟，储存和发芽期间，不利条件会加剧。这会导致胚胎在补液后胚胎经历的基因组应激水平极高。高水平的DNA修复活性在发芽的早期需要在恢复生长之前扭转这种损害，因为修复过程中的失败导致遗传物质的严重诱变，发育受损并最终导致植物死亡。传感DNA损伤会在发芽早期的早期发芽中快速激活，从而延迟发芽，从而延长修复时间或激活细胞死亡。作为启动功能可以扭转这种发芽的延迟，我们假设启动机制中DNA修复和损伤信号过程的核心作用。在这里，我们将使用遗传，生化和高通量分析方法来揭示基因组完整性与启动之间的分子联系，从而确立种子启动的机械基础，以增强种子发芽的增强。培养的种子显示出降低的存储性，从而导致实质性的产量经济损失。种子行业。这种减少寿命的根本原因尚不清楚。但是，我们最近确定，染色体断裂修复中有缺陷的种子显示出启动后的寿命高度降低。这一重要的新结果揭示了在底漆种子中增加的DNA损伤与发芽潜力加速丧失之间的新联系。我们将基于这些结果来揭示底漆种子寿命延长的分子基础，从而确定对减少保质期后生命后播种的特定维修活动的要求。此外，识别与寿命降低相关的信号反应提供了一种有力的方法，可以揭示底漆种子寿命短的根本细胞原因。该项目的最终目的是开发具有改善寿命的新型植物系列，并通过调节活动来启动启动后的寿命这些DNA修复因子。我们将测试关键因素从遗传上提高拟南芥和甘蓝绿色菜的种子发芽的弹性，这是一种对英国农业很重要的农作物。这些方法将解决一个长期存在的问题，即许多蔬菜物种的种子在储存后发芽和建立不良，导致农作物产量降低。综上所述，该项目将根据我们对植物压力反应的了解来实现技术的应用，以提供高质量的种子并支持可持续的农业。

项目成果

Genome damage accumulated in seed ageing leads to plant genome instability and growth inhibition.

• DOI: 10.1042/bcj20230006
• 发表时间: 2023-04-12
• 期刊: The Biochemical journal

Seed DNA damage responses promote germination and growth in Arabidopsis thaliana.

• DOI: 10.1073/pnas.2202172119
• 发表时间: 2022-07-26
• 期刊: Proceedings of the National Academy of Sciences of the United States of America
• 影响因子: 11.1

WHIRLY protein functions in plants

• DOI: 10.1002/fes3.379
• 发表时间: 2022-03
• 期刊: Food and Energy Security
• 影响因子: 5
• 作者: Rachel E. Taylor;C. E. West;C. Foyer