Continuous illumination refers to a photoperiod management method that uses artificial light sources under the condition that the illumination intensity and light quality are determined, and the illumination time exceeds 24 hours. Continuous light can increase the growth of Arabidopsis, lettuce, several types of potatoes, rosettes (Velez-Ramirez et al., 2011). However, continuous light can reduce photosynthetic capacity, maximum in vivo carboxylation rate, and in vivo maximum electron transfer rate (Pettersen et al., 2010), resulting in leaf chlorosis and dieback in some plants.
Eggplants, Ceratops, onions, peanuts, several types of potatoes, tomatoes, etc. are sensitive to continuous light (Velez-Ramirez et al., 2011), which may be related to their low ability to scavenge reactive oxygen species. Therefore, continuous light can be used as a means to study the regulation mechanism of circadian clock and photosynthesis. Whether it can be used as a measure to increase crop yield depends on whether it is economical and whether continuous light damages species differences.
The damage mechanism of continuous light includes: (1) The production and use of photosynthetic products are unbalanced. Significant improvements in leaf starch and sucrose content enhance photosynthesis. Van Gestel et al. (2005) found that the photosynthetic rate of onion leaves with bulb formation did not decrease under continuous light, while the photosynthetic rate of onion leaves without bulb formation decreased. Similar results were obtained with potato studies. Therefore, continuous light damage may be related to the excessive accumulation of photosynthetic products. ② premature senescence of leaves. ③ photooxidative damage. Sugar accumulation caused by continuous light can lead to overreduction of photosynthetic electron transporters, so that electrons are transferred to molecular oxygen to generate reactive oxygen species, which can downregulate the expression of some photosynthesis-related genes, and can also induce programmed cell death and/or Oxidative damage. A variety of factors influence the damage of continuous light to plants. Continuous light damage is serious under strong light, but adding far-red light can reduce the damage. A higher proportion of blue light increases damage, high temperatures aggravate damage, and diurnal fluctuations in temperature prevent damage from continuous light. Partial or full use of sunlight for continuous light treatment can mitigate and prevent damage (Demers and Gosselin, 2012).
Typical state of plant photosynthesis（三）
Continuous lighting
Continuous illumination refers to a photoperiod management method that uses artificial light sources under the condition that the illumination intensity and light quality are determined, and the illumination time exceeds 24 hours. Continuous light can increase the growth of Arabidopsis, lettuce, several types of potatoes, rosettes (Velez-Ramirez et al., 2011). However, continuous light can reduce photosynthetic capacity, maximum in vivo carboxylation rate, and in vivo maximum electron transfer rate (Pettersen et al., 2010), resulting in leaf chlorosis and dieback in some plants.
Eggplants, Ceratops, onions, peanuts, several types of potatoes, tomatoes, etc. are sensitive to continuous light (Velez-Ramirez et al., 2011), which may be related to their low ability to scavenge reactive oxygen species. Therefore, continuous light can be used as a means to study the regulation mechanism of circadian clock and photosynthesis. Whether it can be used as a measure to increase crop yield depends on whether it is economical and whether continuous light damages species differences.
The damage mechanism of continuous light includes: (1) The production and use of photosynthetic products are unbalanced. Significant improvements in leaf starch and sucrose content enhance photosynthesis. Van Gestel et al. (2005) found that the photosynthetic rate of onion leaves with bulb formation did not decrease under continuous light, while the photosynthetic rate of onion leaves without bulb formation decreased. Similar results were obtained with potato studies. Therefore, continuous light damage may be related to the excessive accumulation of photosynthetic products. ② premature senescence of leaves. ③ photooxidative damage. Sugar accumulation caused by continuous light can lead to overreduction of photosynthetic electron transporters, so that electrons are transferred to molecular oxygen to generate reactive oxygen species, which can downregulate the expression of some photosynthesis-related genes, and can also induce programmed cell death and/or Oxidative damage. A variety of factors influence the damage of continuous light to plants. Continuous light damage is serious under strong light, but adding far-red light can reduce the damage. A higher proportion of blue light increases damage, high temperatures aggravate damage, and diurnal fluctuations in temperature prevent damage from continuous light. Partial or full use of sunlight for continuous light treatment can mitigate and prevent damage (Demers and Gosselin, 2012).