Developing conservation strategies for Pinus koraiensis and Eleutherococcus senticosus by using model-based geographic distributions

We described potential changes in the geo- graphic distribution and occurrence probability of Pinus koraiensis Sieb. et Zucc. and Eleutherococcus senticosus （Rupr. et Maxim.） Maxim. in the counties of northeast China. This information was used to identify priority areas for protection and provide protection and management recommendations within each studied county. The two species were mapped in 2884 study plots throughout this region over a 4-year period （38°40＇N-53°30＇N, 115°05＇E- 135°02＇E）. We used the species distribution models （Maxent）, systematic conservation planning models （Marxan）, and Geographic Information Systems （ArcGIS 10.0）. The distributions of two species were correlated in the study area, enabling unique and economically viable joint conservation measures to be implemented. Three models were combined to identify feasible priority con- servation sites. We used local spatial statistics to assess all identified conservation areas in relation to potential climate change based shifts in the geographic distribution of the two species. Model-based conservation strategies were used to identify effective measures to protect and utilize these two tree species in the study region. This study pre- sents a novel technique for assessing wild plant distribu- tions, in addition to serving as a model for the conservation of other species within the framework of general forest management, ecological construction, and geographical surveying.

The Effect of Methylation Modification of MDD on the Expression of Key Genes in the Process of Saponin Synthesis in Eleutherococcus senticosus

Mevalonate pyrophosphate decarboxylase is a kind of key enzyme in the terpenoid synthesis pathway in Eleutherococcus senticosus.The results of bisulfite sequencing showed that there were three kinds of samples with a low(0.68%),medium(0.72%)and high(0.79%)DNA methylation ratio in the promoter of MDD in E.senticosus,respectively.The transcriptome sequencing results showed that the expression of MDD in E.senticosus was significantly up-regulated in the types with low DNA methylation ratios of MDD(P<0.05).There was a significant negative correlation between the saponin content in E.senticosus and the DNA methylation ratio of MDD promoter(P<0.05).The screening results of differentially expressed transcription factors among the three groups with different DNA methylation ratio showed that a total of 4 transcription factors could bind to 6 CpG sites.Protein-protein interaction analysis showed that E.senticosus MDD could interacted with other key enzymes in the process of terpenoid synthesis.In addition,it was found that the DNA methylation of MDD promoter was mainly regulated by DNA methyltransferase.These results demonstrated that under the action of DNA methyltransferase,the changes of DNA methylation of MDD promoter could regulate its own expression level by affecting the combination ability of transcription factors,and then affected the expression of other genes in terpenoid synthesis pathway.The synthesis and accumulation of saponins in E.senticosus was also changed.

刺五加NAC转录因子基因的适应性进化分析

对药用植物刺五加(Eleutherococcus senticosus)的NAC转录因子进行适应性进化分析,使用MEC模型和PAML软件中的3种模型:分支模型、位点模型、分支-位点模型的SLAC、FEL和REL算法对刺五加的116条NAC基因进行适应性进化分析。结果表明:从PAML模型与MEC模型的分析结果中未发现正选择位点,而在分支与位点模型中负选择起主导作用;算法SLAC、REL和FEL的分析结果同样显示,刺五加的NAC转录因子中存在大量负选择位点。通过亚细胞定位和二级结构分析发现,NAC转录因子发挥作用的位置大部分在细胞核中并且大量负选择位点位于无规则卷曲中。结论:纯化选择在NAC转录因子进化过程中发挥主要作用,而NAC转录因子发挥作用的部位可能在无规则卷曲的二级结构中。本文为进一步探究刺五加NAC转录因子的系统进化关系奠定了基础。