Accumulation of UV-absorbing flavonoids induced by UV-B radiation in Arabidopsis thaliana L.

Lois, Rodrigo

doi:10.1007/bf00714462

Cited by 179 publications

(107 citation statements)

References 18 publications

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“…palisade parenchyma cells ; Fig. 1d), as occurs in analogous tissues of Oenothera stricta and Avena sativa Knogge & Weissenbo$ ck, 1986), supports the idea that each tissue type is autonomous in flavonoid biosynthesis and accumulation (Ibrahim, 1992 ;Lois, 1994). It should also be taken into account that in the leaves of plants exposed to high levels of light, UV-A radiation penetrates farther than UV-B and can reach and damage target sites deep within the leaf (Bornman & Vogelmann, 1988).…”

Section: supporting

confidence: 68%

Flavonoids accumulate in leaves and glandular trichomes of Phillyrea latifolia exposed to excess solar radiation

Tattini¹,

Gravano²,

Pinelli³

et al. 2000

New Phytologist

201

175

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Experiments were conducted on Phillyrea latifolia plants grown under a dense overstorey of Pinus pinea (shade plants) or on seashore dunes (sun plants) in a coastal area of Tuscany (42m 46h N, 10m 53h E). Total integrated photon flux densities averaged 1n67 and 61n4 m mol m −# d −" for shade and sun sites, respectively. A leaf morphological-structural analysis, a qualitative and quantitative analysis of phenylpropanoids of leaf tissue and leaf surface, and a histochemical localization of flavonoids were conducted. The area of sun leaves reached 57% of that of shade leaves, whereas leaf angle (β), sclerophylly index (ratio of leaf d. wt : leaf area), and trichome frequency (trichome number mm −# ) were markedly greater in leaves exposed to full solar radiation than in leaves acclimated to shade. The total thickness of sun leaves was 78% higher than that of shade leaves, mostly owing to a greater development of both palisade parenchyma and spongy mesophyll. The concentration, but not the composition, of leaf tissue phenylpropanoids varied significantly between sun and shade leaves, with a marked increase in flavonoid glycosides in sun leaves. Flavonoids occurred almost exclusively in the upper epidermal cells of shade leaves. By contrast, flavonoids largely accumulated in the upper and lower epidermis, as well as in the mesophyll tissue of leaves that were acclimated to full sunlight. Flavonoid glycosides were found exclusively in the secretory products of glandular trichomes of P. latifolia leaves exposed to high levels of light ; luteolin 7-Oglucoside and quercetin 3-O-rutinoside were the major constituents. By contrast, verbascoside and an unidentified caffeic acid derivative constituted 72% of total phenylpropanoids secreted by glandular trichomes of shade leaves, whereas they were not detected in glandular trichomes of sun leaves. These findings suggest that the light-induced synthesis of flavonoids in glandular trichomes of P. latifolia probably occurs in situ and concomitantly inactivates other branch pathways of the general phenylpropanoid metabolism. This is the first report of the key role of glandular trichomes and of flavonoid glycosides in the integrated mechanisms of acclimation of P. latifolia to excess light.

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Section: supporting

confidence: 68%

Flavonoids accumulate in leaves and glandular trichomes of Phillyrea latifolia exposed to excess solar radiation

Tattini¹,

Gravano²,

Pinelli³

et al. 2000

New Phytologist

201

175

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“…Ultra-violet radiation induces flavonoids (particularly kaempferol derivatives) and sinapate esters in A. thaliana and isoflavonoids and psoralens (furanocoumarin) in other species. These UV-absorbing compounds are thought to protect against the damage and subsequent cell death caused by UV-B by protecting DNA from dimerization and breakage (Beggs et al, 1985;Lois, 1994). In healthy tissues the highest level of CHS transcripts were detected in roots, consistent with the biosynthesis of flavonoid derivatives in these tissues (Table II).…”

Section: Discussionmentioning

confidence: 65%

Biosynthesis of secondary metabolites in sugarcane

et al. 2001

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A set of genes related to secondary metabolism was extracted from the sugarcane expressed sequence tag (SUCEST) database and was used to investigate both the gene expression pattern of key enzymes regulating the main biosynthetic secondary metabolism pathways and the major classes of metabolites involved in the response of sugarcane to environmental and developmental cues. The SUCEST database was constructed with tissues in different physiological conditions which had been collected under varied situation of environmental stress. This database allows researchers to identify and characterize the expressed genes of a wide range of putative enzymes able to catalyze steps in the phenylpropanoid, isoprenoid and other pathways of the special metabolic mechanisms involved in the response of sugarcane to environmental changes. Our results show that sugarcane cDNAs encoded putative ultra-violet induced sesquiterpene cyclases (SC); chalcone synthase (CHS), the first enzyme in the pathway branch for flavonoid biosynthesis; isoflavone synthase (IFS), involved in plant defense and root nodulation; isoflavone reductase (IFR), a key enzyme in phenylpropanoid phytoalexin biosynthesis; and caffeic acid-O-methyltransferase, a key enzyme in the biosynthesis of lignin cell wall precursors. High levels of CHS transcripts from plantlets infected with Herbaspirillum rubri or Gluconacetobacter diazotroficans suggests that agents of biotic stress can elicit flavonoid biosynthesis in sugarcane. From this data we have predicted the profile of isoprenoid and phenylpropanoid metabolism in sugarcane and pointed the branches of secondary metabolism activated during tissue-specific stages of development and the adaptive response of sugarcane to agents of biotic and abiotic stress, although our assignment of enzyme function should be confirmed by careful biochemical and genetic supporting evidence.

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“…In herbaceous plants, flavonoids have been shown to have an essential role in u.v.-B attenuation, and the accumulation of flavonoids is assumed to be an efficient protective response of the plant under u.v.-B enhancement (e.g. Stapleton, 1992;Li et aL, 1993;Middleton & Teramura, 1993;Lois, 1994;Reuber et , 1996). Of the u.v.-B-absorbing compounds other than flavonoids, some phenolic acids (sinapyl esters) and carotenoids have recently been acknowledged to play a role in u.v.-protection (Li et aL, 1993;Middleton & Teramura, 1993;van de Staaij et aL, 1995;Sheahan, 1996).…”

Section: Resultsmentioning

confidence: 99%

“…Recently, it has been shown that in some plant species, u.v.-B radiation leads to an increase in the * To whom correspondence should be addressed. E-mail: lavola@joyl.joensuu.fi amounts of fiavonoids and phenolic acids (Li et al, 1993;Middleton & Teramura, 1993;Lois, 1994;van de Staaij et al, 1995;Reuber, Bornman & Weissenbock, 1996;Sheahan, 1996;Lavola, 1997). However, changes in individual phenolic components have not yet been widely reported.…”

Section: Introductionmentioning

confidence: 99%

The effect of u.v.‐B radiation on u.v.‐absorbing secondary metabolites in birch seedlings grown under simulated forest soil conditions

et al. 1997

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Accumulation of UV-absorbing flavonoids induced by UV-B radiation in Arabidopsis thaliana L.

Cited by 179 publications

References 18 publications

Flavonoids accumulate in leaves and glandular trichomes of Phillyrea latifolia exposed to excess solar radiation

Flavonoids accumulate in leaves and glandular trichomes of Phillyrea latifolia exposed to excess solar radiation

Biosynthesis of secondary metabolites in sugarcane

The effect of u.v.‐B radiation on u.v.‐absorbing secondary metabolites in birch seedlings grown under simulated forest soil conditions

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