Light, temperature and circadian clock signal integration during leaf senescence

叶子衰老过程中的光、温度和生物钟信号整合

• 批准号: BB/X014436/1
• 负责人: Keara Franklin
• 金额: $ 54.96万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FX014436%2F1
• 关键词: Light; temperature; circadian; clock; signal

Leaf senescence is an active process involving the remobilisation of nutrients from older, photosynthetically limited tissues to developing plant structures. It is characterised by striking leaf yellowing resulting from the dismantling of chloroplasts and degradation of chlorophyll. Leaf senescence can be induced by environmental stress, such as prolonged darkness and is accelerated at high temperature. In commercial horticulture, leaf senescence in cut produce reduces crop quality and shelf-life, resulting in significant economic losses to growers. This problem is exacerbated by the transport and storage of produce in warm and dark conditions, requiring producers and retailers to invest in costly and environmentally unfriendly refrigeration technologies. Sustainably delaying leaf senescence is a key objective for the fresh food industry, yet cost-effective, practical solutions remain limited. In the model plant Arabidopsis thaliana, dark- induced leaf senescence is promoted by the light, temperature and circadian clock-regulated transcription factors, PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF5. The Franklin lab has shown that low dose (non-stressful) UV-B light treatment can promote rapid degradation of PIF4 and PIF5 proteins and suppress the expression of PIF4 and PIF5 genes in Arabidopsis seedlings. UV-B is filtered by glass in commercial greenhouses and is not a component of horticultural lighting in vertical farms. As such, UV-B is absent in the majority of protected growing environments used in commercial horticulture. We have preliminary evidence that a short (4 hour) preharvest treatment of low dose UV-B can significantly reduce dark-induced senescence in detached Arabidopsis leaves and cotyledons stored at warmer temperatures. This treatment supresses the expression of the key senescence regulator, ORE1 and delays chlorophyll degradation. The proposed work will dissect the molecular signalling pathways through which light, temperature and the circadian clock control dark-induced senescence in detached Arabidopsis leaves. In addition to furthering mechanistic insight into the regulation of a key developmental process, the work will inform strategies for using pre and postharvest light treatments to delay dark-induced leaf senescence in crops. Our preliminary data suggest that preharvest UV-B treatment can delay dark-induced senescence in young rocket (Eruca sativa) leaves, supporting our approach. Overall, the proposed work will provide a molecular framework to address a key problem in sustainable food storage.

叶子衰老是一个活跃的过程，涉及将营养物质从较老的、光合作用受限的组织重新动员到发育中的植物结构。它的特点是叶绿体分解和叶绿素降解导致叶子明显变黄。环境胁迫（例如长时间的黑暗）可以诱导叶子衰老，并且在高温下会加速叶子衰老。在商业园艺中，切割后的作物叶片衰老会降低作物质量和保质期，给种植者带来重大经济损失。在温暖和黑暗的条件下运输和储存农产品会加剧这个问题，要求生产商和零售商投资昂贵且不环保的制冷技术。可持续地延缓叶片衰老是生鲜食品行业的一个关键目标，但具有成本效益的实用解决方案仍然有限。在模型植物拟南芥中，光、温度和生物钟调节转录因子 PHYTOCHROME INTERACTING FACTOR 4 (PIF4) 和 PIF5 促进黑暗诱导的叶片衰老。富兰克林实验室表明，低剂量（无应激）UV-B光处理可以促进拟南芥幼苗中PIF4和PIF5蛋白的快速降解，并抑制PIF4和PIF5基因的表达。 UV-B 在商业温室中被玻璃过滤，不是垂直农场的园艺照明的组成部分。因此，商业园艺中使用的大多数受保护的生长环境中不存在 UV-B。我们有初步证据表明，低剂量 UV-B 的短暂（4 小时）采前处理可以显着减少在较高温度下储存的分离拟南芥叶子和子叶的暗诱导衰老。这种处理可抑制关键衰老调节因子 ORE1 的表达并延迟叶绿素降解。这项工作将剖析光、温度和生物钟控制黑暗诱导的拟南芥叶片衰老的分子信号传导途径。除了进一步深入了解关键发育过程的调控之外，这项工作还将为使用采收前和采后光照处理来延缓黑暗诱导的作物叶片衰老的策略提供信息。我们的初步数据表明，收获前 UV-B 处理可以延缓黑暗诱导的芝麻菜 (Eruca sativa) 叶子的衰老，支持了我们的方法。总体而言，拟议的工作将提供一个分子框架来解决可持续食品储存的关键问题。