When the photosynthetic apparatus (leaves, mesophyll cells, protoplasts or chloroplasts) is transferred from darkness to light, or from weak light to strong light, their photosynthetic rate goes through a long or short step-up process After that, a stable high level, the steady state level, is reached, a phenomenon known as the light-induced phenomenon of photosynthesis, and this process is called the photosynthesis induction period.
The induction period of photosynthesis can be as short as a few minutes and as long as 1 to 2 hours, which is controlled by the activity of photosynthetic carbon assimilation enzymes, the accumulation of photosynthetic carbon assimilation intermediates, and the time it takes for leaf surface stomata to open. In addition, it can prolong the photosynthetic induction period at low temperature, long dark treatment time before illumination and too low phosphorus concentration. When water is deficient or the air humidity is low, the photosynthetic induction period is significantly elongated. Moreover, under adverse conditions, even if a dark period of 5mim is applied, it still needs a longer induction period to reach steady state after re-illumination.
At a certain light intensity, after photosynthesis ends and the light induction reaches a steady state, the response curve of the photosynthetic rate to the change of light intensity is the photosynthesis light response curve. On this curve, the light compensation point and the light saturation point can be obtained. Long et al. (2006) believed that the photosynthesis of C3 plants reached light saturation at about 25% of the sunlight intensity, which was about 500 Hmol/m2·s. But in fact, the light saturation point of soybean and wheat leaves grown indoors is 600-700 Hmol/m2, .s, while the field is around 1000 Hmol/m2 s, and wheat even reaches 1600 Hmol/m2 s.
Typical state of plant photosynthesis（一）
photoresponse
When the photosynthetic apparatus (leaves, mesophyll cells, protoplasts or chloroplasts) is transferred from darkness to light, or from weak light to strong light, their photosynthetic rate goes through a long or short step-up process After that, a stable high level, the steady state level, is reached, a phenomenon known as the light-induced phenomenon of photosynthesis, and this process is called the photosynthesis induction period.
The induction period of photosynthesis can be as short as a few minutes and as long as 1 to 2 hours, which is controlled by the activity of photosynthetic carbon assimilation enzymes, the accumulation of photosynthetic carbon assimilation intermediates, and the time it takes for leaf surface stomata to open. In addition, it can prolong the photosynthetic induction period at low temperature, long dark treatment time before illumination and too low phosphorus concentration. When water is deficient or the air humidity is low, the photosynthetic induction period is significantly elongated. Moreover, under adverse conditions, even if a dark period of 5mim is applied, it still needs a longer induction period to reach steady state after re-illumination.
At a certain light intensity, after photosynthesis ends and the light induction reaches a steady state, the response curve of the photosynthetic rate to the change of light intensity is the photosynthesis light response curve. On this curve, the light compensation point and the light saturation point can be obtained. Long et al. (2006) believed that the photosynthesis of C3 plants reached light saturation at about 25% of the sunlight intensity, which was about 500 Hmol/m2·s. But in fact, the light saturation point of soybean and wheat leaves grown indoors is 600-700 Hmol/m2, .s, while the field is around 1000 Hmol/m2 s, and wheat even reaches 1600 Hmol/m2 s.