Cell-type-specific environmental signal integration networks controlling a binary developmental switch during the life cycle of plants

不断增长的人口对农业提出了越来越高的要求，目前的产量需要在2050年之前翻一番。使这一挑战雪上加霜的是气候变化的影响，它限制了我们之前预期的产量。迫切需要开发出能抵抗环境变化的限产影响的作物品种。该项目所产生的信息对于在一系列环境条件下成功开发具有可持续高产的新作物品种将是至关重要的。为了确保它们的生存和繁殖成功，植物已经进化出了在它们的生命周期中改变决策时间的能力，以响应来自环境的各种信号。植物发育过程中的关键选择包括决定繁殖或开始开花，以及决定开始生长，这始于种子的萌发。这两个转变都受到来自环境的不止一个信号的影响，包括光、温度和营养。信号整合的过程描述了将多个信息合并到一个判决中。这种信息的融合发生在植物中，通过各种分子之间的一系列复杂的相互作用。这个项目将使用种子萌发作为一个模型系统，以了解不同的环境信号如何整合到一个单一的二元决策中，以终止休眠并开始萌发。许多调节种子对环境的反应的个体因素以前已经被发现。尚不清楚的是，这些独立组件如何相互作用以形成信号集成网络。这项提议将通过定义植物用来将不同的环境线索合并为开始生长的单一决定的分子网络来填补我们理解的这一空白。该项目还将定义信号整合过程中以前未知的部分，并解释来自环境的信息如何传递到最终决定的分子目标。众所周知，植物使用多条信息来指导它们的发育过渡，但目前还不清楚这一决策过程发生在哪些细胞中。该提案将调查植物胚胎中一个专门的细胞亚群的作用，我们最近发现了这个亚群，在这个位置上，不同的信号整合到一个单一的决定中。环境控制每个细胞内信号整合网络的方式将被确定，这是植物细胞决策中心的特征。从这个项目中获得的信息将代表着我们在广泛的环境条件下发展产量强劲的作物的能力的一步变化。以前利用单个组分改变植物对环境的反应的尝试取得的成功有限，这主要是因为缺乏对这些孤立因素如何通过分子信号整合网络中的一系列复杂相互作用发挥影响的了解。为了准确和有力地改变植物对环境的反应，我们必须首先了解这些网络是什么，以及它们如何发挥作用来控制植物的反应。这些知识可以用来战术上干扰关键的相互作用，而不是单个组件，以实现所需的输出。另一个限制植物对环境反应成功的因素是缺乏对这些过程的空间控制的理解。不同的决策是在不同的地点做出的。针对做出关键决定的特定细胞内存在的相互作用进行针对性修改的能力，将极大地增强我们改变植物行为以响应环境的能力。

A growing human population is placing increasing demands on agriculture, with current production needing to double by the year 2050. Compounding this challenge are the effects of climate change which are limiting the yields we have previously come to expect. The need to develop crop varieties resistant to the yield-limiting effects of environmental change is urgent. The information generated by this project will be vital to the successful development of new crop varieties with sustainably high yields across a range of environmental conditions.In order to ensure their survival and reproductive success, plants have evolved the ability to alter the timing of decisions during their life cycle in response to a wide variety of signals from their environment. Key choices during plant development include the decision to reproduce, or start flowering, and the decision to commence growth, which begins with the germination of their seeds. Both of these transitions are influenced by more than one cue from the environment, including light, temperature and nutrients. The process of signal integration describes the incorporation of multiple pieces of information into a single verdict. This amalgamation of information occurs in plants through a complex series of interactions between various molecules. This project will use seed germination as a model system to understand how diverse environmental signals are integrated into a single binary decision, to terminate dormancy and start germination. Many individual factors mediating seed responses to the environment have been uncovered previously. What is not known is how these individual components interact with one another to form a signal integration network. This proposal will fill this gap in our understanding by defining the molecular network which plants use to merge diverse environmental cues into a single decision to commence their growth. The project will as well define previously uncharacterized components of the signal integration process, and explain how information from the environment is passed onto the final molecular targets that drive the final decision.It is well known that plants use multiple pieces of information to guide their developmental transitions, yet it much less clear in which cells this decision-making process occurs. The proposal will investigate the role of a specialized sub-group of cells within the plant embryo that we have recently uncovered as a site where diverse signals are integrated into a single decision. The way the environment controls the signal integration network within each of these cells will be determined, characterizing a cellular decision-making centre in plants. The information derived from this project will represent a step change in our ability to develop crop plants with robust yields across a wide range of environmental conditions. Previous attempts to modify plant response to the environment using individual components have been met with limited success, largely due to the lack of understanding of how these isolated factors exert their influence through a complex series of interactions within molecular signal integration networks. In order to accurately and robustly modify plant response to the environment, we must first understand what these networks are, and how they function to control plant responses. This knowledge can be used to tactically perturb key interactions, rather than individual components, to achieve a desired output.Another factor limiting the success of modifying plant response to the environment is a lack of understanding of the spatial control of these processes. Distinct decisions are made within distinct sites. The ability to target modifications to interactions present within specific cells that are making key decisions will greatly enhance our ability to modify plant behaviour in response to the environment.