受控环境农业(CEA)对于在世界许多地区实现全年粮食安全至关重要。CEA是一项资源密集型工作,照明消耗了很大一部分能量。减轻电网负担,节约成本,扩展的光周期策略可以利用公用事业供应商的非高峰时间选择。然而,延长光周期会在形态和生理上限制作物生产,如果推动时间过长。这里,我们提出了一种连续光动态发光二极管(LED)策略(涉及光谱的变化,强度,和时间安排),克服了这些限制。我们专注于番茄,一种描述良好的光周期损伤敏感物种,还有迷你黄瓜,一种耐光周期损伤的物种,首先评估控制下的形态反应(16小时光周期,不变的光谱),常数(24小时光周期,不变的光谱),以及动态LED策略的两种变体,动态1(16小时\"天\",3-h“峰值”,8小时“夜间”光谱)和动态2(20小时“白天”,5-h\"峰值\",4小时“夜间”光谱)。接下来,我们通过使用叶片气体交换与叶绿素荧光协议,检验了光呼吸参与光周期损伤的假设。我们通过使用MultispeQ仪器探测光合电子流和质子流,进一步探索了三磷酸腺苷(ATP):烟酰胺腺嘌呤二核苷酸磷酸(NADPH)比率的供需响应。我们发现顶篷结构可以通过相同动态LED策略的微小变化来调整,我们强调动态1是番茄和迷你黄瓜的最佳选择,因为它提高了生物量/结构和第一产量,分别。一个主要发现是动态1的光呼吸水平明显高于对照,这两个物种。出乎意料的是,在相同处理下,物种之间的光呼吸是相当的,除了在常数下。然而,在恒定处理下生长的完全耐性番茄基因型的初步数据上调了光呼吸,类似于迷你黄瓜。这些结果表明,光周期损伤耐受性涉及在延长的光周期下持续较高水平的光呼吸。有趣的是,昼夜的MultispeQ测量指出了主观夜间循环电子流的重要性,这也可以部分解释为什么动态LED策略可以减轻光周期损伤。我们提出了涉及光呼吸的光周期损伤的本体论,磷酸丙糖的利用,过氧化物酶体H2O2-过氧化氢酶平衡,和启动程序性细胞死亡的灵敏度的昼夜节律外部符合模型。
Controlled environment agriculture (CEA) is critical for achieving year-round food security in many regions of the world. CEA is a resource-intensive endeavor, with lighting consuming a large fraction of the energy. To lessen the burden on the grid and save costs, an extended photoperiod strategy can take advantage of off-peak time-of-day options from utility suppliers. However, extending the photoperiod limits crop production morphologically and physiologically if pushed too long. Here, we present a continuous-light dynamic light-emitting diode (LED) strategy (involving changes in spectra, intensity, and timing), that overcomes these limitations. We focused on tomato, a well described photoperiodic injury-sensitive species, and mini-cucumber, a photoperiodic injury-tolerant species to first assess morphological responses under control (16-h photoperiod, unchanging spectrum), constant (24-h photoperiod, unchanging spectrum), and two variations of a dynamic LED strategy, dynamic 1 (16-h \"day\", 3-h \"peak\", 8-h \"night\" spectra) and dynamic 2 (20-h \"day\", 5-h \"peak\", 4-h \"night\" spectra). Next, we tested the hypothesis of photorespiration\'s involvement in photoperiodic injury by using a leaf gas exchange coupled with chlorophyll fluorescence protocol. We further explored Adenosine triphosphate (ATP): Nicotinamide adenine dinucleotide phosphate (NADPH) ratio supply/demand responses by probing photosynthetic electron flow and proton flow with the MultispeQ instrument. We found canopy architecture can be tuned by minor variations of the same dynamic LED strategy, and we highlight dynamic 1 as the optimal choice for both tomato and mini-cucumber as it improved biomass/architecture and first-yield, respectively. A central discovery was that dynamic 1 had a significantly higher level of photorespiration than control, for both species. Unexpectedly, photorespiration was comparable between species under the same treatments, except under constant. However, preliminary data on a fully tolerant tomato genotype grown under constant treatment upregulated photorespiration similar to mini-cucumber. These results suggest that photoperiodic injury tolerance involves a sustained higher level of photorespiration under extended photoperiods. Interestingly, diurnal MultispeQ measurements point to the importance of cyclic electron flow at subjective nighttime that may also partially explain why dynamic LED strategies mitigate photoperiodic injury. We propose an ontology of photoperiodic injury involving photorespiration, triose phosphate utilization, peroxisomal H2O2-catalase balance, and a circadian external coincidence model of sensitivity that initiates programmed cell death.