Physiological Characteristics of Photosynthesis in Yellow-Green, Green and Dark-Green Chinese Kale (Brassica oleracea L. var. alboglabra Musil.) under Varying Light Intensities

Abstract

The objective of this work was to study physiological characteristics and photosynthetic apparatus in differentially pigmented leaves of three Chinese kale cultivars. Chlorophyll (Chl) fluorescence and photochemical reflectance index (PRI) measurements in green, yellow-green, and dark-green cultivars in response to varying light intensities. As light intensity increased from 200 to 2000 photosynthetic photon flux density (PPFD), fraction of light absorbed in photosystem (PS) II and PRI values in all plants were strongly lowered, but fraction of light absorbed in PSII dissipated via thermal energy dissipation and non-photochemical quenching (NPQ) values in all plants wereremarkably elevated.When plants were exposed to 200 PPFD, the values of fraction of light absorbed in PSII, utilized in photosynthetic electron transport(p), andfraction of light absorbed excitation energy in PSII dissipated via thermal energy dissipation (D), remained stable regardless of the changes in levels of Chla + b. Under 800 and 1200 PPFD, the values of p and electron transport rate (ETR) decreased, but D and NPQ increased as Chla + bcontent decreased, suggesting that decrease inChla + bcontent led to lower PSII efficiency and it became necessary to increase dissipate excess energy. On the contrary, in 2000 PPFD, leaves with lower Chla + bcontent had relatively higher p and electron transport rate (ETR) values and lower D level, as well as tended to increase more in NPQ but decrease more in PRI values. The consistent relations between PRI and NPQ suggest that NPQ is mainly consisted ofthe xanthophyll cycle-dependentenergy quenching.Yellow-green cultivar showed lower Chla + bcontent but high carotenoids/Chla + b ratio and had high light protection ability under high PPFD. The precise management of photosynthetic parameters in response to light intensity can maximize the growth and development of Chinese kale plants.

Genome‐wide identification of the light‐harvesting chlorophyll a/b binding (Lhc) family in Gossypium hirsutum reveals the influence of GhLhcb2.3 on chlorophyll a synthesis

“…reinhardtii and contains a CB domain (Ortiz‐Torres et al ., 2020). Photosynthesis of higher plants mainly uses chlorophyll and carotenoids, which are closely related to photoprotection (Lin et al ., 2020). Lhc family proteins are nuclear‐encoded thylakoid proteins that bind to pigments (chlorophyll a , chlorophyll b and some carotenoids) (Jansson, 1999).…”

Effects of Temperature, Relative Humidity, and Carbon Dioxide Concentration on Growth and Glucosinolate Content of Kale Grown in a Plant Factory

“…The most likely reason for this phenomenon is that chlorophyll is an indicator of the health of the photosynthetic apparatus, and the concentration (amount per mass) is a function of the leaf area. As the midrib and petiole of kale (depending on the cultivar) are large, the midrib might become enlarged, diluting the concentration of chlorophyll in the lamina during the growth period, which results in negative correlations with other growth variables [ 60 ]. Moreover, the efficiency of chlorophyll varies over time due to the engagement–disengagement of assorted photoprotective mechanisms under fluctuating light conditions.…”

Physiological adaptation and transcriptome changes in the plateau plant common vetch (Vicia sativa L.) in response to the plain environment

“…Chlorophyll synthesis, stomata and leaf structure of common vetch in the plain environment Light is the direct energy source of plant growth. Among them, light intensity is one of the most important factors that affect many physiological processes of plants, such as photosynthesis [17,18]. There is a threshold for the effect of light intensity on the growth of plants; light intensity that is too high or too low will inhibit the growth of plants [19].…”