Effects of Short-term Red Radiation and Choline Compounds on Cytokinin Content, Chlorophyll Accumulation and Photomorphogenesis in Wheat Seedlings

Abstract

Effects of choline compounds (2-chloroethyltrimethylammonium chloride and 2-ethyltrimethylammonium chloride) as well as red radiation (R) pulse on the dynamics of cytokinin changes, growth and chlorophyll (a + b) accumulation were studied during the growth and greening of etiolated wheat seedlings (Triticum aestivum L., var. Mironovskaya-808). The seedlings were grown for 120 h in the dark and then exposed for 72 h to white light. Pre-treatment of caryopses with cholines and pre-irradiation of etiolated seedlings with R inhibited elongation of both coleoptile and first leaf; but the same factors accelerated these growth responses when seedlings were exposed to white light. Chlorophyll (Chl) accumulation and the first leaf appearance from coleoptile were accelerated by the pre-treatments as well. Far-red radiation (FR) reversed all effects of R but choline pre-treatment eliminated partly R/FR photoreversibility. Two compounds with high cytokinin activity (tested on a fresh weight basis by the bioassay with Amaranthus caudatus L.) were found in shoots and first leaves. One of them had R f , UV absorbance spectrum and the biological activity similar to N 6 -(D 2 -isopentenyl)adenosine. Another cytokinin-like substance was not identified with the used standards. Stimulation of greening by R pulse and cholines was accompanied with accelerated accumulation of both cytokinin-like substances. We conclude that the influence of R and cholines on the concentration of substances with cytokinin activities detected in the leaves might be involved in the stimulation of Chl accumulation.

Effect of choline amino acid ionic liquids on maize seed germination and endogenous plant hormone levels

“…For example, 2-chloroethyltrimethylammonium chloride and 2-ethyltrimethylammonium chloride increased plant chlorophyll content, which was related to its increase in leaf cytokinin levels. 42 Genetic engineering of the biosynthesis of glycinebetaine could enlarge the fruit size and enhance the productivity of tomato, which was related to the contents of phytohormones, such as auxin, brassinolide, gibberellin, and cytokini. 43 Moreover, JA-GA network influences the intensity of defense responses.…”

Presowing Treatment of Seeds of Spring Wheat With Low-Frequency Electromagnetic Field

“…In recent years, electrophysical treatment methods for plants and seeds of grain, vegetable and legume crops have been introduced extensively into agricultural practices to intensify plant growing [8,9]. Physical factors influencing seeds may include electromagnetic fields of various ranges (from -radiation to UHF radio-frequency range), X-ray radiation, ultraviolet and optical radiation (particularly, laser red radiation with = 632.8 nm), infrared radiation, electric corona field, and ultrasonic exposure [10,11].…”

Photosynthesis of Rehmannia glutinosa subjected to drought stress is enhanced by choline chloride through alleviating lipid peroxidation and increasing proline accumulation

“…It has been shown that the capacity to scavenge active oxygen species as well as proline accumulation may be manipulated by using plant growth regulators (Singh andUsha 2003, Diaz et al 2005). Choline chloride (CC) could regulate lipid concentration and composition (Novitskaya et al 2004), affect cytokinin concentration and morphogenesis (Kreslavski et al 2005), and increase resistance of photosynthetic apparatus to UV-B radiation and elevated temperature (Kreslavski et al 2001). Whether CC can increase the tolerance of photosynthetic apparatus to drought stress to our knowledge is not clear.…”