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Surely our efforts need to be concentrated on maximising the light energy delivered in the spectra used by our plant?
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Absolutley.However, evolution has already taken place so if the plant only used specific wavelengths much of the light energy from the sun would be lost to photosynthesis because the photons would lack sufficient energy to drive the reactions. So it turns out the the reaction center pigments, P680 and P700, are chlorophyll pigments absorbing light maximally at 680 and 700 nanometers...in the low-energy red-end of the visible spectrum. Of course if plants could only absorb 680 and 700 nanometer light, they would be missing a lot of light. So evolution has provided chlorophyll a with a range of other pigments, antenna pigments, that absorb higher-energy wavelengths and pass the absorbed energy on to chlorophyll a. Thus plants can utilize light from every wavelength in the visible spectrum from 400 to 700 nm. This is best observed by examining the action spectrum for a particular plant.
And photosynthesis is not the only light dependant reaction I am trying to cater to in our favorite plant. Plants can sense light direction, quality (wavelength), intensity and periodicity. Light induces phototropism, photomorphogenesis, chloroplast differentiation and various other responses such as flowering and germination.
Light quality is mainly sensed by the presence of different light receptors specific for different wavelengths. The red/far red photoreceptors are called phytochrome. There are at least 2 classes of blue light receptors; cryptochrome recognizes blue, green and UV-A light, while phototropin perceives blue light.
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Here is an experiment where they grew under 667nm, 737nm, or a combo of the two. It should give you an idea of the improtance of other wavelengths to healthy plants.
read this and tell me what you think
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