Impact of soil nitrate and chloride content on transpiration of crop plants (Acronym: “An-Trans”)

土壤硝酸盐和氯化物含量对作物蒸腾作用的影响（缩写：“An-Trans”）

• 批准号: 498546397
• 负责人: Professor Dr. Christoph-Martin Geilfus
• 金额: --
• 依托单位: Lehrstuhl für Botanik I: Molekulare Pflanzenphysiologie und Biophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/498546397?language=en
• 关键词: Impact; soil; nitrate; chloride; content

In many parts of Europe, agriculture is facing two major challenges: crop plants are likely to encounter progressive soil water scarcity and, at the same time, crops in some areas must be supplied with less nitrogen to prevent groundwater and surface water pollution by nitrates. Both challenges are interrelated, since low soil water availability will reduce transpiration and the mass-flow driven uptake of nutrients such as nitrate (NO3−) and chloride (Cl−). In return, the uptake, i.e. the presence of NO3− and Cl− in the leaf, has been shown to affect stomatal movements and thus will have an important impact on water usage by crops. In the envisaged project, the relationship between the soil NO3−-to-Cl− ratio and stomatal movements will be studied on two crop plants; the dicotyledonous legume broad bean and the cereal barley. Both crops are likely to differ in their dependence on NO3− and Cl− for regulation of the stomatal conductance, since stomatal closure in barley depends on NO3− in the apoplast, while this requirement has not been found for dicotyledonous plants. Moreover, it is not known if barley or broad bean guard cells prefer the uptake of NO3− over Cl−, to drive stomatal opening.The project will study the impact of the NO3−-to-Cl− ratio in the soil on stomata in four work packages (WPs), which span the range of experiment with whole plants (WP1) via ion, metabolite and hormone analysis (WP2), single cell experiments (WP3) to the analysis of single transport proteins (WP4). In WP1, the relation between different NO3−-to-Cl− ratios in the soil will be linked to the ability of our model plants to regulate both stomatal movements and leaf hydration. In WP2, we will study to which extend different NO3−-to-Cl− ratios affect the ion, metabolite and hormone (ABA) concentration of the leaf apoplast and the guard cell symplast, while WP3 will show to which extend the anion composition (NO3−, Cl−) can affect stomatal movements. We will test if guard cells of broad bean and barley prefer NO3−, or Cl−, to accompany the osmotic processes that drive stomatal movements. Finally, WP4 will focus on the role of NPF transporters in the uptake NO3− and Cl− into guard cells and the SLAC1-like anion channels that can release these anions. While SLAC1-like channels have been shown to play a major role in regulation of stomatal movements, only little information is available for uptake of NO3− and Cl− into guard cells by NPF-proteins. The results of our project will help to predict both the impact of progressive soil drying and a reduction of NO3−-N input in soils on transpiration by dicotyledonous and cereal crop plants. In this way, mechanistic information is provided that can be integrated into breeding programs for crops with superb regulatory capabilities for stomatal conductance and water consumption.

在欧洲许多地区，农业正面临两大挑战：作物可能会遇到土壤水资源逐步短缺的问题，同时，某些地区的作物必须减少氮供应，以防止硝酸盐污染地下水和地表水。这两个挑战是相互关联的，因为低土壤水分可用性将减少蒸腾作用和质量流驱动的营养素吸收，如硝酸盐（NO3−）和氯化物（Cl−）。反过来，吸收，即叶片中NO3−和Cl−的存在，已被证明会影响气孔运动，从而对作物的用水量产生重要影响。在所设想的项目中，将对两种作物-双子叶豆科蚕豆和谷类大麦-的土壤NO3−/Cl −比率与气孔运动之间的关系进行研究。这两种作物在调节气孔导度时对NO3−和Cl−的依赖性可能不同，因为大麦的气孔关闭依赖于质外体中的NO3−，而双子叶植物中没有发现这种要求。此外，大麦或蚕豆保卫细胞是否更喜欢吸收NO3−而不是Cl−来驱动气孔开放尚不清楚。该项目将在四个工作包（WP）中研究土壤中NO3−与Cl −的比例对气孔的影响，这些工作包涵盖了整个植物实验（WP 1）的范围，通过离子，代谢物和激素分析（WP 2），单细胞实验（WP 3）到单转运蛋白的分析（WP 4）。在WP 1中，土壤中不同的NO3−与Cl −比率之间的关系将与我们的模型植物调节气孔运动和叶片水合作用的能力相关联。在WP 2中，我们将研究不同的NO3−-to-Cl −比例在何种程度上影响叶质外体和保卫细胞共质体的离子，代谢物和激素（阿坝）浓度，而WP 3将显示阴离子组成（NO3−，Cl−）在何种程度上影响气孔运动。我们将测试蚕豆和大麦的保卫细胞是否更喜欢NO3-或Cl-来伴随驱动气孔运动的渗透过程。最后，WP 4将重点关注NPF转运蛋白在将NO3−和Cl−摄取到保卫细胞中的作用，以及可以释放这些阴离子的SLAC 1样阴离子通道。虽然SLAC 1-like通道已被证明在调节气孔运动中发挥重要作用，但只有很少的信息可用于NPF-蛋白质将NO3-和Cl-吸收到保卫细胞中。我们项目的结果将有助于预测土壤逐渐干燥和土壤中NO3−-N输入减少对双子叶植物和谷类作物蒸腾作用的影响。通过这种方式，提供了可以整合到作物育种计划中的机械信息，这些作物对气孔导度和水分消耗具有极好的调节能力。