RESEARCH-PGR: Cycling to low-temperature tolerance

每年的反常寒流都会造成农作物的重大损失，影响全球粮食安全并限制种植范围。这个项目的重点是了解如何使高粱--一种对干旱和高温高度耐受的低投入作物--对低温更具弹性。从植物的自然生物钟及其与耐寒基因的联系中获得灵感，在Panicoid草中探索了对低温耐性至关重要的转录物、脂肪和代谢物的日常波动，Panicoid草是高粱和玉米所属的植物科。提高高粱的低温耐受性可以增强美国大平原的农业可持续性，减轻反常寒流对作物产量的影响。此外，目前提高作物低温耐受性的努力是以牺牲作物的整体健康为代价的。这个项目通过探索植物对温度变化的日常反应节奏，挑战了测量和设计作物低温耐受性的传统方法。它有可能重塑人们对耐冷性的理解，并改变多种作物的耐冷性。为了提高公众对随着日常节律变化的植物行为的认识，将与内布拉斯加州州立博物馆合作创建一个互动展览，展示植物的昼夜行为及其与低温耐受性的关系。这个展览通过巡回展览到达内布拉斯加州的乡村学校，旨在让公众了解和参与这些科学发现对农业和食品安全的重要性。该项目的长期目标是确定通过有节奏的调控来降低与提高高粱耐寒性相关的健身成本的方法。为了实现这一点，对高粱和具有较强耐寒性的近缘谷子进行了比较分析。推动这项研究的主要假设有两个：1)对潘尼科牧草耐冷性所必需的关键节律转录本和代谢物的鉴定仍然不完整，2)与耐冷性机制相关的适应性成本可以通过节律性表达来抵消。这些假设得到了初步数据的支持，并通过两个目标进行了检验。首先，通过对寒冷的节律性反应，鉴定对耐冷性至关重要的新转录物和脂类和可溶性代谢物。基于在初步研究中观察到的Paniclike草转录本和脂肪丰度的强烈节律性，本目标结合多种组学和节律性分析来揭示先前未知的影响低温耐受性的代谢和转录模块。确定的模块调节子将在拟南芥中表达并测试其低温耐受性，作为概念的证明。第二，确定时钟对低温耐受性的控制程度，确定促进工具。高粱的时钟功能在遗传上受到干扰，谷子则受到持续光照的影响，以评估它们对低温耐性的影响。来自耐寒小米的潜在节律启动子也将在敏感的高粱物种中进行测试，以建立耐受性工程工具。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Unseasonal cold spells annually cause significant losses in crops, impacting global food security and constraining growing ranges. This project focuses on understanding how sorghum, a low-input crop highly tolerant to drought and heat, can be made more resilient to low temperatures. Drawing inspiration from the natural circadian clock of plants and its connections to cold tolerance genes, daily fluctuations in transcripts, lipids, and metabolites crucial for low temperature tolerance are explored in Panicoid grasses, the plant family to which sorghum and maize belong. Improving sorghum's low temperature tolerance could enhance agricultural sustainability in the U.S. Great Plains, mitigating the impact of unseasonal cold spells on crop yields. Additionally, current efforts to enhance low-temperature tolerance in crops comes at a cost to their overall health. This project challenges traditional approaches to measuring and engineering low temperature tolerance in crops, by exploring the daily rhythms of plant responses to temperature changes. It has the potential to reshape how cold tolerance is understood and engineered in multiple crops. To raise public awareness of plant behaviors that change with daily rhythms, an interactive exhibit showcasing plant diurnal behaviors and their connection to low temperature tolerance will be created in collaboration with the Nebraska State Museum. This exhibit, reaching Nebraskan rural schools through a traveling display, aims to inform and engage the public in the importance of these scientific discoveries for agriculture and food security.The long-term goal of this project is to identify methods to mitigate fitness costs associated with increasing cold tolerance of sorghum through rhythmic regulation. To achieve this, a comparative analysis is conducted between sorghum and close genetic relative foxtail millet, which exhibits greater cold tolerance. The primary hypotheses driving the research are twofold: 1) The identification of key rhythmic transcripts and metabolites essential for cold tolerance in Panicoid grasses remains incomplete, and 2) The fitness cost associated with cold tolerance mechanisms can be counteracted through rhythmic expression. These hypotheses are supported by preliminary data and tested through two objectives. First, identify novel transcripts and lipid and soluble metabolites critical to cold tolerance by their rhythmic response to cold. Building upon strong rhythmicity observed in transcript and lipid abundances in Panicoid grasses during preliminary investigations, this objective uses a combination of multiple omics and rhythmicity analyses to reveal previously unrecognized metabolic and transcriptional modules influencing low-temperature tolerance. Identified module regulators will be expressed and tested for low-temperature tolerance in Arabidopsis as a proof of concept. Second, determine the extent of clock control of low temperature tolerance and identify promoter tools. Clock function is disrupted genetically in sorghum and by continuous light exposure in foxtail millet to assess their impact on low-temperature tolerance. Potentially rhythmic promoters from the cold-tolerant foxtail millet will also be tested in the susceptible sorghum species to establish tools for tolerance engineering.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.