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.

叶片衰老是一个积极的过程，涉及从较老的，光合限制的组织到发展植物结构的养分。它的特征是叶绿体拆除和叶绿素降解引起的叶片泛黄。叶片衰老可以通过环境压力（例如长时间的黑暗度）诱导，并在高温下加速。在商业园艺中，切割农产品的叶片衰老会降低作物质量和保质期，从而对种植者造成了巨大的经济损失。在温暖和黑暗的条件下，农产品的运输和储存使生产商和零售商投资于昂贵和环境不友好的制冷技术，这使这个问题加剧了。可持续的延迟叶片衰老是新鲜食品行业的关键目标，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，暗诱导的叶片衰老是由光，温度和昼夜节律调节的转录因子，植物色素相互作用因子4（PIF4）和PIF5促进的。富兰克林实验室已经表明，低剂量（非压力）UV-B光处理可以促进PIF4和PIF5蛋白的快速降解，并抑制拟南芥幼苗中PIF4和PIF5基因的表达。 UV-B在商业温室中被玻璃过滤，并且不是垂直农场园艺照明的组成部分。因此，在商业园艺中使用的大多数保护环境中，UV-B不存在。我们有初步的证据表明，低剂量UV-B的短期（4小时）治疗可以显着减少脱离的拟南芥叶子和在较高温度下储存的子叶中的黑暗引起的衰老。这种治疗方法抑制了关键衰老调节剂ORE1的表达，并延迟了叶绿素降解。所提出的工作将阐述分子信号通路，通过该通路，光，温度和昼夜节律控制着脱落的拟南芥叶片的黑暗诱导衰老。除了进一步洞悉关键发育过程的调节外，该作品还将为使用前和后光处理的策略提供依据，以延迟作物中黑暗引起的叶片衰老。我们的初步数据表明，预先获得的UV-B治疗可以延迟Young Rocket（Eruca sativa）叶片的黑暗引起的衰老，从而支持我们的方法。总体而言，拟议的工作将提供一个分子框架，以解决可持续食品存储中的关键问题。