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Environmental and developmental effects on the biosynthesis of UV-B screening pigments in Scots pine (Pinus sylvestris L.) needles.
- Source :
-
Plant, cell & environment [Plant Cell Environ] 2006 Aug; Vol. 29 (8), pp. 1484-91. - Publication Year :
- 2006
-
Abstract
- The major UV-B screening pigments of the epidermal layer of Scots pine (Pinus sylvestris) needles are flavonol 3-o-glycosides (F3Gs) esterified with hydroxycinnamic acids at positions 3" and 6". Acylation is the last step in biosynthesis and is catalysed by position-specific hydroxycinnamoyl transferases (3" and 6"HCT). The UV-B dependence of these enzyme activities was studied in primary needles of Scots pine seedlings grown under different UV-B conditions in environmentally controlled sun simulators. 6"HCT activity was induced upon UV-B irradiation while 3"HCT activity was not induced but showed high constitutive values. To investigate the biosynthesis of diacylated F3Gs during needle development under natural conditions, the HCT activities and metabolite contents were analysed in needles of field-grown mature pine trees. Accumulation of diacylated compounds as well as of 6"HCT activity occurred transiently in the first year of needle development only. In contrast, 3"HCT activity exhibited broad maxima in two consecutive years during needle growth. The data suggest that acylated F3Gs are first formed as soluble compounds which are then translocated into the cell wall to be bound by their hydroxycinnamoyl residues.
- Subjects :
- Acyltransferases metabolism
Cell Wall metabolism
Esterification
Pigments, Biological radiation effects
Pinus sylvestris growth & development
Pinus sylvestris radiation effects
Seasons
Seedlings growth & development
Seedlings metabolism
Seedlings radiation effects
Coumaric Acids metabolism
Flavonols biosynthesis
Glycosides biosynthesis
Pigments, Biological biosynthesis
Pinus sylvestris metabolism
Ultraviolet Rays
Subjects
Details
- Language :
- English
- ISSN :
- 0140-7791
- Volume :
- 29
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- Plant, cell & environment
- Publication Type :
- Academic Journal
- Accession number :
- 16898012
- Full Text :
- https://doi.org/10.1111/j.1365-3040.2006.01518.x