Velez-Ramirez Aaron I, Dünner-Planella Gabriela, Vreugdenhil Dick, Millenaar Frank F, van Ieperen Wim
Horticulture and Product Physiology, Wageningen University, PO Box 630, 6700 AP Wageningen, The Netherlands.
Laboratory of Plant Physiology, Wageningen University, PO Box 658, 6700 AR Wageningen, The Netherlands.
Funct Plant Biol. 2017 Jun;44(6):597-611. doi: 10.1071/FP16285.
Unlike other species, when tomato plants (Solanum lycopersicum L.) are deprived of at least 8h of darkness per day, they develop a potentially lethal injury. In an effort to understand why continuous light (CL) is injurious to tomato, we tested five factors, which potentially could be responsible for triggering the injury in CL-grown tomato: (i) differences in the light spectral distribution between sunlight and artificial light, (ii) continuous light signalling, (iii) continuous supply of light for photosynthesis, (iv) continuous photo-oxidative pressure and (v) circadian asynchrony - a mismatch between the internal circadian clock frequency and the external light/dark cycles. Our results strongly suggest that continuous-light-induced injury does not result from the unnatural spectral distribution of artificial light nor from the continuity of light per se. Instead, circadian asynchrony seems to be the main factor inducing the CL-induced injury, but the mechanism is not by the earlier hypothesised circadian pattern in sensitivity for photoinhibition. Here, however, we show for the first time diurnal fluctuations in sensitivity to photoinhibition during normal photoperiods. Similarly, we also report for the first time diurnal and circadian rhythms in the maximum quantum efficiency of PSII (Fv/Fm) and the parameter F0.
与其他物种不同，当番茄植株（茄属番茄L.）每天被剥夺至少8小时黑暗时，它们会受到潜在的致命伤害。为了理解为什么持续光照（CL）对番茄有害，我们测试了五个因素，它们可能是导致CL处理番茄受伤的原因：（i）阳光和人造光之间的光谱分布差异，（ii）持续光照信号，（iii）持续供应用于光合作用的光，（iv）持续的光氧化压力，以及（v）昼夜节律失调——内部昼夜节律频率与外部光/暗周期之间的不匹配。我们的结果强烈表明，持续光照诱导的伤害并非源于人造光的非自然光谱分布，也不是源于光照本身的持续性。相反，昼夜节律失调似乎是诱导CL诱导伤害的主要因素，但其机制并非如早期假设的对光抑制敏感性的昼夜节律模式。然而，在这里我们首次展示了正常光周期下对光抑制敏感性的昼夜波动。同样，我们也首次报告了PSII最大量子效率（Fv/Fm）和参数F0的昼夜节律和昼夜节律。
