Cambium Reactivation Is Closely Related to the Cell-Cycle Gene Configuration in Larix kaempferi.

Dormancy release and reactivation in temperate trees are mainly controlled by temperature and are affected by age, but the underlying molecular mechanisms are still unclear. In this study, we explored the effects of low temperatures in winter and warm temperatures in spring on dormancy release and reactivation in Larix kaempferi. Further, we established the relationships between cell-cycle genes and cambium cell division. The results showed that chilling accelerated L. kaempferi bud break overall, and the longer the duration of chilling is, the shorter the bud break time is. After dormancy release, warm temperatures induced cell-cycle gene expression; when the configuration value of the cell-cycle genes reached 4.97, the cambium cells divided and L. kaempferi reactivated. This study helps to predict the impact of climate change on wood production and provides technical support for seedling cultivation in greenhouses.

LaDAL1 Coordinates Age and Environmental Signals in the Life Cycle of Larix kaempferi.

Perennial woody plants are long-lived, and their life-cycle events occur in order in each generation, but what drives the occurrence and restart of these events in their offspring is unknown. Based on its age-dependent expression pattern and function, Larix kaempferi DEFICIENS-AGAMOUS-LIKE 1 (LaDAL1), a MADS transcription factor has been suggested to be a time recorder and life-cycle event coordinator. Here, we studied the dynamic spatiotemporal expression pattern of LaDAL1 in the life cycle of L. kaempferi to analyze the molecular mechanism of life-cycle progression. In full view of the life cycle, LaDAL1 transcription was related with life-cycle progression, and its transcript level increased sharply from age 3 to 5 years, which might be the molecular characteristic of the vegetative phase change, and then stayed at a high level. During sexual reproduction, LaDAL1 transcript level decreased sequentially during meiosis and embryogenesis, suggesting that meiosis rapidly lowers the age signal, and after fertilization, the age signal was reset to "0" with the embryogenesis. When a seed germinates, the next generation restarts, and the age is re-counted. Altogether, these results not only provide important and novel insights into the life-cycle progression and transgeneration in perennial woody plants, but also advance our understanding of age recording.

[Determination of anaprazole in human plasma by LC-MS/MS in pharmacokinetic study].

Anaprazole is a proton pump inhibitor clinically used for curing peptic ulcer. A rapid, sensitive and convenient LC-MS/MS method was first established for the determination of anaprazole in human plasma. d(3), (13)C-anaprazole was used as internal standard (IS). After extraction from human plasma by protein precipitation with acetonitrile, all components were separated on an Extend C(18) column (100 mm × 4.6 mm, 3.5 µm). The assay was linear over the concentration range of 5.00-3 000 ng·m L(-1) (r(2) > 0.995). The method was successfully applied to a pharmacokinetic study of 40 mg anaprazole enteric-coated tablets in 14 Chinese healthy volunteers under fasting or high fat diet conditions. C(max) was (1 020 ± 435) ng·m L(-1) and AUC(0-t) was (2 370 ±754) h·ng·m L(-1) under fasting condition. And C(max) was (538 ± 395) ng·m L(-1) and AUC(0-t) was (1 610 ± 650) h·ng·m L(-1) under high fat diet condition. The plasma results suggest that the exposure of anaprazole is reduced by the high fat diet.