Testing a cytokinin dilution model of floral duration in barley

植物开花产生的种子和果实提供了人类社会消耗的绝大多数卡路里。植物试图通过正确地定时开花的开始和持续时间来优化它们的繁殖成功，以产生“正确”数量的种子以适应当时的环境条件。在谷类作物中，包括英国的主要作物大麦，开花的持续时间决定了花朵的数量，以及作物的“产量潜力”。使用模式植物拟南芥，我们最近表明，植物激素细胞分裂素的浓度决定了拟南芥花多长时间。随着细胞分裂素在越来越大的芽系统中被稀释，植物停止生产和开放花朵，导致开花结束。根据初步证据，我们认为，同样的机制也调节开花的持续时间-从而提高产量潜力-在谷类作物。我们假设，增加细胞分裂素的敏感性，谷物将因此增加开花的持续时间和产量潜力。在这项提案中，我们的目标是使用高分辨率表型分析，先进的生物成像，转录组学和经典和分子遗传学的组合来测试这一假设。了解控制开花期的机制将使我们能够挑战目前对作物产量的限制，并及时改变大麦和其他主要谷类作物的产量潜力。这将有助于满足生产更多粮食以养活不断增长的全球人口的迫切需要。

The seeds and fruit produced by flowering in plants provides the vast majority of calories consumed by human societies. Plants attempt to optimize their reproductive success by correctly timing the initiation and duration of flowering, to produce the 'correct' number of seed for prevailing environmental conditions. In cereal crops, including the key UK crop barley, the duration of flowering determines the number of flowers formed, and the 'yield potential' of the crop. Using the model plant Arabidopsis thaliana, we have recently shown that the concentration of the plant hormone cytokinin determines how long Arabidopsis flowers for. As cytokinin becomes diluted across the increasingly large shoot system, plants stop producing and opening flowers, leading to the end of flowering. Based on preliminary evidence, we believe that this same mechanism also regulates duration of flowering - and hence yield potential - in cereal crops. We hypothesise that increasing cytokinin sensitivity in cereals will therefore increase the duration of flowering and their yield potential. In this proposal, we aim to test this hypothesis using a combination of high-resolution phenotyping, advanced bioimaging, transcriptomics and classical and molecular genetics. Understanding the mechanisms controlling flowering duration will allow us to challenge current limitations on crop yields, and drive a timely change in yield potential in barley and other key cereal crops. This will help to meet the pressing need to produce more food to feed the growing global population.