Photosynthesis light intensity

Fig. 2. Effects of light intensity and quality, and cell concentration on the volumetric oxygen evolution rate by algal photosynthesis. Li t types and cell concentration used ( ) simulated daylight and 0.215 g L" (A) simulated daylight and 0.123 g L (A) red light and 0.123 g L" and (o) green light and 0.123 g V. ...

In photosynthetic bacteria, (i.e., Chlorobiaceae) the bacteriochlorophyUs support photosynthesis at low light intensities, and they accomplish this activity by using a unique antenna complex known as a chlorosome in which the pigments are located. Since these bacteria are strict anaerobes, photosynthesis is nonoxygenic. ... 

Effect of temperature, light intensity, and evaporative stress on photosynthesis and respiration... 

Insofar as they have been studied, all herbicides that inhibit the Hill reaction of isolated chloroplasts also inhibit photosynthesis of intact plants and photosynthetic microorganisms (2, 3). Phy to toxicity is produced only in the light, and severity of symptoms is proportional to light intensity. Studies with light quality have indicated that the chlorophylls are the principal absorbing pigments involved in the production of phytotoxicity. 

Leaf transpiration rates closely parallel photosynthetic rates over a range of light intensities (i.e., 400 to 1200 pmol m 2 sec 1) (Soja and Haunold, 1991). Water use efficiency, therefore, remains rather stable relative to photosynthesis until the light intensity drops below 300 pEm-2-sec 1. Here water use efficiency decreases sharply, with transpiration being higher relative to photosynthesis. 

The maximum quantum yield of photosynthesis (FvIFm) varied with daily dynamics in light intensity in both the iron-limited and iron-replete cells (Fig. 1A). Maximum values were recorded in the morning, followed by decreasing values towards the middle of the light period. In replete cells, the midday depression was almost 50% of the morning values FvIFm decreased by about 30% under iron limitation. The FJFm recovered towards the end of... 

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