Search

[ Objective ] The authors analyzed the population structure and dynamic characteristics in differ- ent habitats and explored the main influential factors , so as to provide basis for the protection , restora- tion , and renewal of the population in this area. [ Methods ] In order to understand the population structure and dynamic characteristics in different habitats , the static life table , survival curve , and survival analysis function curve of the population were drawn by investigating the population of the Trachycarpus nanus in three different habitats ( broad-leaved forest , mixed forest , and thicke ) in Dajianshan Nature Reserve of Chuxiong. Population dynamics were predicted by using the time series model. [ Results ] ( 1 ) In the three habitats , the population was in a declining state , and was sensitive to external interference. The survival curve was Deevey-Ⅲ type , and a large number of individuals died in the seedling stage. ( 2 ) In the three habitats , the distribution of T . nanus population was uneven and clustered , indicating that seed spreading of the T . nanus was centered around the mother plant. [ Conclusion ] The population density of T . nanus was the highest in the broad-leaved forest , followed by the mixed forest , and the smallest was shrub. Combined with the study on the population age structure , it was further proved that the broad-leaved for- est and the mixed forest with better water conditions were more conducive to the survival of the population.

Aging is often accompanied by irreversible decline in body function, which causes a large number of age-related diseases and brings a huge economic burden to society and families. Many traditional Chinese medicines have been known to extend lifespan, but it has still been a challenge to isolate a single active molecule from them and verify the mechanism of anti-aging action. Drugs that inhibit senescence-associated secretory phenotypes (SASPs) are called "senomorphics". In this study, arctigenin (ATG), a senomorphic, was screened from the Chinese medicine Fructus arctii using K6001 yeast replicative lifespan. Autophagy, oxidative stress, and telomerase activity are key mechanisms related to aging. We found that ATG may act through multiple mechanisms to become an effective anti-aging molecule. In exploring the effect of ATG on autophagy, it was clearly observed that ATG significantly enhanced autophagy in yeast. We further verified that ATG can enhance autophagy by targeting protein phosphatase 2A (PP2A), leading to an increased lifespan. Meanwhile, we evaluated the antioxidant capacity of ATG and found that ATG increased the activities of the antioxidant enzymes, thereby reducing reactive oxygen species (ROS) and malondialdehyde (MDA) levels to improve the survival of yeast under oxidative stress. In addition, ATG was able to increase telomerase activity by enhancing the expression of EST1, EST2, and EST3 genes in yeast. In conclusion, ATG exerts anti-aging effects through induction of autophagy, antioxidative stress, and enhancement of telomerase activity in yeast, which is recognized as a potential molecule with promising anti-aging effects, deserving in-depth research in the future. [ABSTRACT FROM AUTHOR]