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Lilium brownii (F. E. Brown) Miellez var. colchesteri E. H. Wilson has a unique characteristic in its flower color, which changes from yellowish-cream to white one day after anthesis. To elucidate the mechanism of flower color change in this species, the content and composition of carotenoids were analyzed during two days of anthesis. The major carotenoids that contributed to the yellowish-cream color of the tepals were lutein, zeaxanthin, and β-carotene. Analysis showed an obvious decrease in total carotenoid content of the tepal, indicating that the flower color change is caused by the reduction of the total carotenoid content after anthesis. To reveal the factor that controls carotenoid content in the tepals, we isolated carotenoid cleavage dioxygenase 4 (LbCCD4) gene and analyzed the number of LbCCD4 messages by quantitative real-time PCR. The transcription level of LbCCD4 gene increased and reached the maximum level 12 hours after anthesis. The results suggest that the carotenoids in yellow tepals of L. brownii var. colchesteri degraded into colorless compounds by carotenoid cleavage dioxygenase and subsequently resulted in white flowers.

The role of temperature in bulb dormancy induction and release was investigated in one-year-old seedlings of three populations of Lilium longiflorum, i.e., Yakushima (LYA) and Kikaijima (LKI) in the Ryukyu Archipelago, Japan and Pitouchiao (LPI), Taiwan, and two populations of L. formosanum, Wulai (FWU), Taiwan and domesticated Fukuoka population (FFU), Japan. LYA and LKI undergo deep summer dormancy, while LPI, FWU and FFU do not. Four weeks of high temperature induced dormancy in LYA and LKI, whereas two weeks of high temperature was insufficient. Dormancy was not induced in LPI and FFU even after eight weeks of high temperature. Re-growth after dormancy was initiated in LKI and LYA six to eight weeks after shifting to 15°C. In the temperature-controlled experiment, all the populations continued developing new leaves at 15°C for 22 weeks, and stopped leaf production at 20 and 25°C in winter, while FFU produced new leaves at 30°C. It is considered that summer dormancy induction and release in one-year-old seedlings of northern ecotypes of L. longiflorum is determined by the duration of high and low temperature, respectively. It was proved that development of non-or weakly dormant ecotypes of L. longiflorum and L. formosanum is associated with the lack or reduction of sensitiveness to high temperature.

BackgroundUrban air pollution is an increasing health problem, particularly in Asia, where the combustion of fossil fuels has increased rapidly as a result of industrialization and socio-economic development. The adverse health impacts of urban air pollution are well established, but less is known about effective intervention strategies. In this demonstration study we set out to establish methods to assess whether wearing an R95 activated carbon respirator could reduce intake of polycyclic aromatic hydrocarbons (PAH) in street workers in Hanoi, Vietnam.MethodsIn this demonstration study we performed a cross-over study in which non-smoking participants that worked at least 4 hours per day on the street in Hanoi were randomly allocated to specific respirator wearing sequences for a duration of 2 weeks. Urines were collected after each period, i.e. twice per week, at the end of the working day to measure hydroxy PAHs (OH-PAH) using gas chromatography/high resolution mass spectrometry. The primary endpoint was the urinary concentration of 1-hydroxypyrene (1-OHP).ResultsForty-four participants (54.5% male, median age 40 years) were enrolled with the majority being motorbike taxi drivers (38.6%) or street vendors (34.1%). The baseline creatinine corrected urinary level for 1-OHP was much higher than other international comparisons: 1020 ng/g creatinine (IQR: 604–1551). Wearing a R95 mask had no significant effect on 1-OHP levels: estimated multiplicative effect 1.0 (95% CI: 0.92-1.09) or other OH-PAHs, except 1-hydroxynaphthalene (1-OHN): 0.86 (95% CI: 0.11-0.96).ConclusionsHigh levels of urine OH-PAHs were found in Hanoi street workers. No effect was seen on urine OH-PAH levels by wearing R95 particulate respirators in an area of high urban air pollution, except for 1-OHN. A lack of effect may be de to gaseous phase PAHs that were not filtered efficiently by the respirator. The high levels of urinary OH-PAHs found, urges for effective interventions.Trial registrationISRCTN74390617 (date of assignation: 04/08/2009).