The Relationship between Photosynthetic Pigments and Light Absorption

Light environment is one of the important physical environmental factors indispensable for plant growth and development. through light quality regulation,artificial light can meet the photosynthetic needs of crops and control photomorphogenesis .led grow light is an important technology in the field of facility cultivation.a proper spectrum is very important for indoor planting. Because it can maximize the potential for consumed energy converting into photons needed by plants for photosynthesis and avoid energy waste.

A series of responses of plants to the external light environment are based on light absorption by photoreceptors. The main receptors include photosynthetic pigments, photosensitive pigments, cryptochrome and phototropins. They play their respective roles in plants and affect the photosynthetic physiology, metabolic physiology, morphological formation and other aspects of plants.

The photosynthetic pigments are vital components of the machinery of photosynthesis. Chlorophyll, carotenoids and phytochrome are the main components involved in photosynthesis and photomorphogenesis of crops. Understanding the absorption of these pigments on light is of great reference significance for determining the spectrum of led grow light for plants.

More pigments means more glucose or food for the plant!

chlorophyll (a and b )is a primary pigment involved in the photosynthesisprocess of plants. It is mainly responsible for the photosynthetic process of light energy reception, energy transfer and photoelectric conversion.

Chlorophyll A light absorption curve

Chlorophyll B light absorption curve

Carotenoids are a class of phytonutrients and are found in the cells of a wide variety of plants. They help plants absorb light energy for use in photosynthesis. These pigments play an important role in plant health.

Carotenoids light absorption curve

Photosensitive pigments are formed by covalent combination of chromogenic groups and decoco-base proteins, including far-red absorption type (Pfr) and red-light absorption type (Pr). They mainly absorb the red light of 600-700nm and 700-760nm, and regulate physiological activities of plants through the reversible action of far-red and red light. In plants, photosensitive pigments are mainly involved in the regulation of seed germination, seedling formation, photosensitive system establishment, shade avoidance, flowering time and circadian rhythm response. In addition, it also plays a regulatory role in the anti-stress physiology of plants.

Phytochrome Red light absorption curve

Phytochrome Far-Red light absorption curve

Phototropin is a blue-light receptor found after photosensitive pigments and cryptochrome, which can bind to flavin mononuclide for phosphorylation. It can regulate phototaxis, chloroplast movement, stomatal opening, leaf extension and hypocotyl elongation of yellow seedling

Phototropins

Cryptochrome is A blue light receptor. It mainly absorbs blue light of 320-500nm and uV-A of near-ULTRAVIOLET light, and its absorption peaks are approximately 375nm, 420nm, 450nm and 480nm. Cryptochrome is mainly involved in the regulation of flowering in plants. In addition, it is also involved in regulating plant directional growth, stomatal opening, cell cycle, development of guard cells, root development, abiotic stress, apical dominance, fruit and ovule development, programmed cell death, seed dormancy, pathogen response and magnetic induction.

Cryptochromes light absorption curve