title: Effect of increased UV-B radiation on carotenoid accumulation and total antioxidant capacity in tobacco (Nicotiana tabacum L.) leaves.
abstract: Carotenoids are important components of plant antioxidant systems, which protect photosystems from photooxidative destruction during ultraviolet-B (UV-B) exposure. The influence of carotenoids on total antioxidant capacity (TAC) of plants has rarely been studied. In this study, tobacco (Nicotiana tabacum L., 'K326') seedlings exposed to UV-B radiation were used in order to evaluate the effects of ambient levels of UV-B radiation on carotenoid accumulation. The aim was to investigate whether carotenoids could enhance TAC as a means of UV protection. Our results showed that leaf carotenoid content in the low UV-B exposure (+9.75 μW/cm2) plants was approximately 8% higher than that observed in control plants at 2-8 days of exposure. At high UV-B exposure (+20.76 μW/cm2), the carotenoid content increased rapidly after 1 day's exposure (10.41% higher than the control), followed by a return to the content as in control plants. Furthermore, carotenoid content positively correlated with TAC (P = 0.024). These results suggest that carotenoids have antioxidant properties and play an important role in the antioxidant system. UV-B exposure increased the carotenoid synthesis capability of plants. The plants could deplete the carotenoids to scavenge excess ROS at high UV-B radiation levels, which protects the tobacco plant from oxidative damage caused by UV-B stress.
authors.affiliation: Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei City, Anhui Province, China.
authors.forename: J
authors.initials: J
authors.lastname: Shen
authors.affiliation: Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei City, Anhui Province, China.
authors.forename: C Q
authors.initials: CQ
authors.lastname: Jiang
authors.affiliation: Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei City, Anhui Province, China.
authors.forename: Y F
authors.initials: YF
authors.lastname: Yan
authors.affiliation: Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei City, Anhui Province, China.
authors.forename: B R
authors.initials: BR
authors.lastname: Liu
authors.affiliation: Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei City, Anhui Province, China lcz2468@sina.com.
authors.forename: C L
authors.initials: CL
authors.lastname: Zu
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism / Q000528:radiation effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000378:metabolism / Q000528:radiation effects; D014026:Nicotiana / Q000378:metabolism* / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D002338:Carotenoids