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The PRI is sensitive to changes in carotenoid pigments (e.g. xanthophyll pigments) in live foliage. Carotenoid pigments are indicative of photosynthetic light use efficiency, or the rate of carbon dioxide uptake by foliage per unit energy absorbed. As such, it is used in studies of vegetation productivity and stress.
Violaxanthin is a xanthophyll pigment with an orange color found in a variety of plants. Violaxanthin is the product of the epoxidation of zeaxanthin where the oxygen atoms are from reactive oxygen species (ROS). Such ROS's arise when a plant is subject to solar radiation so intense that the light cannot all be absorbed by the chlorophyll. [2]
Phaeophytin a: [1] a gray-brown pigment; Phaeophytin b: [1] a yellow-brown pigment; Chlorophyll a: a blue-green pigment; Chlorophyll b: a yellow-green pigment; Chlorophyll a is the most common of the six, present in every plant that performs photosynthesis. Each pigment absorbs light more efficiently in a different part of the electromagnetic ...
Values of PPFD are normally expressed using units of mol⋅m −2 ⋅s −1. In relation to plant growth and morphology, it is better to characterise the light availability for plants by means of the Daily Light Integral (DLI), which is the daily flux of photons per ground area, and includes both diurnal variation as well as variation in day ...
Standard refractive index measurements are taken at the "yellow doublet" sodium D line, with a wavelength (λ) of 589 nanometers. There are also weaker dependencies on temperature , pressure / stress , etc., as well on precise material compositions (presence of dopants , etc.); for many materials and typical conditions, however, these ...
Delphinidin (also delphinidine [1] [2]) is an anthocyanidin, a primary plant pigment, and also an antioxidant. [3] Delphinidin gives blue hues to flowers in the genera Viola and Delphinium. It also gives the blue-red color of the grape variety Cabernet Sauvignon, and can be found in cranberries and Concord grapes as well as pomegranates, [4 ...
Pelargonidin can be found in red geraniums (Geraniaceae). It is the predominant pigment causing the red coloration in the spathes of Philodendron (Araceae). The orange-coloured flowers of blue pimpernel (Anagallis monelli, Myrsinaceae) have a higher concentration of pelargonidin pigment.
In higher plants, there are three carotenoid pigments that are active in the xanthophyll cycle: violaxanthin, antheraxanthin, and zeaxanthin. During light stress, violaxanthin is converted, i.e. reduced, to zeaxanthin via the intermediate antheraxanthin, which plays a direct photoprotective role acting as a lipid-protective anti-oxidant and by ...