Solar UV-B radiation influences carotenoid accumulation of tomato fruit through both ethylene-dependent and -independent mechanisms.
The effect of UV-B shielding on ethylene production in ripening tomato fruits and the contribution of ethylene and UV-B radiation on carotenoid accumulation and profile during ripening were assessed to get more insight about the interplay between these two regulatory factors. To this aim, rin and nor tomato mutants, unable to produce ripening ethylene, and cv Ailsa Craig were cultivated under control or UV-B depleted conditions until full fruit ripening. The significantly decreased ethylene evolution following UV-B depletion, evident only in Ailsa Craig, suggested the requirement of functional rin and nor genes for UVB-mediated ethylene production. Carotenoid content and profile were found to be controlled by both ethylene and UV-B radiation. This latter influenced carotenoid metabolism either in an ethylene-dependent or -independent way, as indicated by UVB-induced changes also in nor and rin carotenoid content and confirmed by correlation plots between ethylene evolution and carotenoid accumulation performed separately for control and UV-B shielded fruits. In conclusion, natural UV-B radiation influences carotenoid metabolism in a rather complex way, involving ethylene-dependent and -independent mechanisms, which seem to act in an antagonistic way.
Becatti
Elisa
E
Department of Agricultural Chemistry and Biotechnology, University of Pisa, via del Borghetto 80, I-56124 Pisa.
Petroni
Katia
K
Giuntini
Deborah
D
Castagna
Antonella
A
Calvenzani
Valentina
V
Serra
Giovanni
G
Mensuali-Sodi
Anna
A
Tonelli
Chiara
C
Ranieri
Annamaria
A
D002338:Carotenoids / Q000032:analysis / Q000378:metabolism*; D002734:Chlorophyll / Q000032:analysis; D005030:Ethylenes / Q000096:biosynthesis / Q000494:pharmacology*; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014975:Lutein / Q000032:analysis; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D013472:Sunlight; D014466:Ultraviolet Rays; D019207:beta Carotene / Q000032:analysis
D005030:Ethylenes; D019207:beta Carotene; D002734:Chlorophyll; D002338:Carotenoids; C036216:ethylene; D014975:Lutein