Phytochrome-mediated induction of phenylalanine ammonia-lyase in the cotyledons of tomato (Lycopersicon esculentum Mill.) plants

Abstract

Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5.) induction in cotyledons from 96-h dark-grown Lycopersicon esculentum Mill. was studied in response to continuous light and hourly light pulses (blue, red, far red). The increases of PAL promoted by blue and red pulses are reversed completely by immediately following 758 nm irradiations. The response to continuous red light could be substituted for by hourly 6-min red light pulses. The effect of continuous red treatments is mainly due to a multiple induction effect of phytochrome. In contrast to red light, hourly light pulses with far red and blue, light can only partially substitute for continuous irradiation. The continuous blue response could be due to a combination of a multiple induction response and of a high irradiance response of phytochrome. The continuous far red response, could represent a high irradiance response of phytochrome. Dichromatic irradiations indicate that phytochrome is the photoreceptor controlling the light response (PAL) in tomato seedlings.

UV-B induction of NADP-malic enzyme in etiolated and green maize seedlings

“…The specific mechanism for the induction of phenylalanine ammonia‐lyase (PAL), an enzyme that participates in flavonoid biosynthesis, is unclear. It has been suggested (Lercari, Sodi & Fastami 1982) that phytochrome is the sole photoreceptor involved in PAL induction, although the data do not completely rule out two photoreceptors. In tomato as well as in Arabidopsis , both ultraviolet radiation and phytochrome sensitivity have been demonstrated for hypocotyl photomorphogenic responses (Thomas & Dickinson 1979; Young, Liscum & Hangarter 1992).…”

Photoregulation of phenylalanine ammonia‐lyase (PAL) and chalcone synthase (CHS) in the accumulation of anthocyanin in alpine and prairie ecotypes of Stellaria longipes under varied R/FR

“…1991). In tomato, red light initiated a strong photoinduction of PAL activity, which could be reversed by a subsequent pulse of FR (Lercari et al. 1982).…”