Exploiting night-time traits to improve wheat yield and water use efficiency in the warming climate of North-western Mexico

小麦是世界上种植最广泛的谷类作物：超过35%的人类依赖它作为主食来源。小麦的产量（每公顷吨）是可变的，取决于当地气候和水等资源的可用性。由于人口增加和土地利用压力等因素，有必要不断提高小麦的“遗传产量”。然而，由于气候变化导致的大气温度上升和水资源减少的双重影响，每年的产量增长日益受到威胁。包括墨西哥在内的脆弱小麦产区，如果由于不利的温度和/或水分供应而导致小麦产量下降或歉收，将面临生产力下降和经济困难。因此，培育具有更高水分利用效率和耐高温性的小麦品系至关重要。本项目旨在获得新的遗传和生理信息，以提高墨西哥西北部小麦的水分利用效率和耐热性。高温与水分有效性呈明显的负相关关系。温度也是植物和作物生长过程的调节器，是调节发育的核心。高温可能是胁迫的主要来源，影响光合作用、呼吸作用、光呼吸作用和活性氧的产生。在墨西哥，水对小麦产量很重要，该国84%的小麦需要灌溉。还有强有力的证据表明，墨西哥西北部的平均气温正在迅速上升。然而，越来越清楚的是，最低（夜间）温度正在导致谷物产量下降。尽管如此，大多数研究都集中在白天温度的影响上，而对夜间特征及其基因调控知之甚少。在这里，我们关注的是夜间水分流失及其与夜间温度升高的关系：众所周知，小麦叶片在夜间通过蒸腾作用（即使在干旱情况下）也会损失大量水分，而且这一特性存在遗传变异。该项目将通过开发夜间筛选小麦夜间蒸腾资源的新技术来克服这一知识差距。我们将在索诺兰地区的田间应用操纵试验作物夜间温度的方法。该项目将汇集专家组：诺丁汉大学（英国）拥有小麦作物光合作用和根系表型的专业知识；拥有水和环境科学专业知识的索诺拉研究所Tecnológico；Earlham研究所（英国）的小麦基因组分析。这种伙伴关系对于该项目的成功和应用成果是必要的，这些成果将改善墨西哥西北部地区的小麦品系。我们将开发在不同最低温度下小麦叶片电导夜间表型的新工具，并将其应用于田间（索诺拉）和受控环境（英国）的遗传多样性小麦组。我们将描述夜间（和白天）电导的新变化，并将其与水灌溉和水限制条件下的产量联系起来。我们将对产生这一有趣而重要的过程的茎和根的生理机制有新的认识，并指出可能存在的任何权衡。对这些品系进行基因分型将产生可立即用于小麦育种的标记，这些标记将用于提高和维持墨西哥西北部的小麦产量。因此，该项目将为该地区的种植者带来立竿见影的效益，并将为“气候保护”农业和当地经济做出重大贡献。

Wheat is the most widely grown cereal crop in the world: over 35 % of humans are reliant on it as a staple food source. Yields (tonnes per hectare) of wheat are variable, depending on local climate and the availability of resources such as water. Due to factors such as an increasing human population and pressures on land use there is a need to continually improve the 'genetic yield' of wheat. However the annual yield gains are increasingly threatened by the double impact of rising atmospheric temperatures and lowered water availability caused by climate change. Vulnerable wheat producing regions, including Mexico, face lowered productivity and economic difficulties if wheat yields decline or fail as a result of adverse temperatures and/or water availability. Therefore generating wheat lines with increased water use efficiency and high temperature tolerance is critically important. This project proposal aims to generate novel genetic and physiological information that is necessary to improve water use efficiency and heat tolerance of wheat in NW Mexico. High temperature and water availability have a clear negative relationship. Temperature is also a regulator of plant and crop processes, being central to the regulation of development. High temperatures can be a major source of stress, affecting photosynthesis, respiration, photorespiration and the generation of active oxygen. Water is important for wheat yields in Mexico with up to 84 % of wheat in this country requiring irrigation. There is also strong evidence that the mean temperatures in NW Mexico are rapidly rising. However it is becoming clear that the minimum (NIGHT TIME) temperatures are contributing to yield decline in cereals. Despite this, most work has focussed on the effect of day time temperatures while very little is known about nocturnal traits and their genetic regulation. Here we focus on the puzzle of night time water loss and its relationship with increasing night time temperatures: it is known that wheat leaves can lose a substantial amount of water at night via transpiration (even under drought) and there is genetic variation for this trait. This project will overcome this knowledge gap by producing novel techniques for night time screening of promising wheat germplasm for night time transpiration. We will apply methods for manipulating nocturnal temperatures of experimental crops in the field in the Sonoran region.This project will bring together expert groups: the University of Nottingham (UK) which has expertise in photosynthetic and root phenotyping of wheat crops; Instituto Tecnológico de Sonora with expertise in water and environmental science; The Earlham Institute (UK) for wheat genomic analysis. This partnership is necessary for this project to succeed and to apply results that will result in improved wheat lines for the NW Mexico region. We will develop new tools for night time phenotyping of wheat leaf conductance under different minimum temperatures and apply them to a genetically diverse panel of wheat in the field (Sonora) and in controlled environments (UK). We will characterise novel variation in night time (and day time) conductance, link this to yield in water- irrigated and water limited conditions. We will gain new understanding of the shoot and root physiological mechanisms that give rise to this interesting and important process, pinpointing any tradeoffs that may exist. Genotyping of these lines will give rise to markers that can immediately be used in breeding wheat that will be used to improve and maintain wheat yields in NW Mexico. Hence this project will be of immediate benefit to growers in this region and will be a substantial contribution to 'climate-proof' agriculture and the local economy.