Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-26 Cooperative journals: 《广西植物》
Abstract： The genetic diversity of species was a key factor in their adaptability and survival capabilities. Habitat fragmentation was recognized as one of the key factors leading to biodiversity loss, and it had significant impacts on the genetic diversity of plant populations. Hydrocera triflora was in a regional extinction state, and the status of its genetic diversity and endangered mechanisms had not been reported. In this study, 34 samples of H. triflora from 7 populations were used to obtain single nucleotide variation sites by restriction site-associated DNA sequencing (RAD-seq). We discussed the mechanisms of endangerment of H. triflora by analyzing population genetic diversity and structure. Additionally, we combined these findings with historical population dynamics analysis and predictions of potential species distribution in different climate scenarios. The results were as follows: (1) H. triflora had low genetic diversity (Ho=0.1569, He=0.1654, Pi=0.1865) and low genetic differentiation; AMOVA analysis showed that genetic variation mainly occurred within populations; (2) The Mantel test indicated that there was a significant positive correlation between environmental distance and genetic distance, as well as geographical distance, with respective p-values of 0.0447 and 0.0082; (3) The effective population size of H. triflora had been continuously declining since the mid-Holocene. The eruption of the Qiongbei volcanic group and human activities played a significant role; (4) Compared to the modern climate, the total potential distribution area of H. triflora changed little in the future. However, in scenarios of high CO2 emissions, the highly suitable area decreased significantly, especially in the Malay Islands where the suitable habitat virtually disappeared. The results indicated that habitat fragmentation led to a continuous decline in the genetic diversity and effective population size of the H. triflora. Therefore, the low self-renewal capacity, as well as detrimental environmental conditions such as human disturbance and urbanization, were the primary factors contributing to its endangered status. On the one hand, it was recommended to strengthen the in-situ protection of the H. triflora, employing techniques such as artificial pollination to enhance gene flow among populations and thereby increase genetic diversity. On the other hand, we should focus on protecting wetlands from destruction.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-06-05 Cooperative journals: 《广西植物》
Abstract： Except for Cymbidium lancifolium, all the Cymbidium species have been listed as national key protected wild plants, and the research of its future distribution patterns under the future climate would provide a reference and basis to protect this genus effectively. This paper gathered the distribution information of Cymbidium and 19 climatic factors, and used the Maximum Entropy Model (MaxEnt) and Geographic Information System (ArcGIS) to predict the future distribution patterns of the Cymbidium in China and its 20 species. The future distribution patterns were predicted under nine different climate scenarios, including the current climate and eight future climate scenarios. We also analyzed the dominant climate factors affecting the distribution. The results were as follows: (1) The precipitation of the driest quarter (Bio17), annual precipitation (Bio12) and temperature seasonality (Bio04) are the dominant climate factors affecting the future distribution of Cymbidium. (2) The analysis of species-level shows that the suitable areas of different Cymbidium species have different change trends in the future scenario, and the dominant climate factors affecting them are also different. The suitable habitat area of eight Cymbidium species such as C. dayanum trends gradually increases, while the suitable habitat area of 12 Cymbidium species such as C. tracyanum decreases. In conclusion, this study can provide an important reference for in-situ and ex-situ conservation of Cymbidium, and has positive significance to the protection of Cymbidium and other endangered wild plants.
Subjects: Biology >> Bioengineering submitted time 2017-07-24 Cooperative journals: 《中国生物工程杂志》
Abstract： Objective To obtain the recomninant protein as HCMV subunit vaccine, the dominant antigen epitope gene of protein pp65 and gB of human cytomegalovirus (HCMV) were expressed in E. coli, and the humoral and cellular immune responses of the recombinant protein in Balb/c mice were detected. Methods The coden genes of 490 - 508 aa in pp65 protein and 607 - 621 aa in gB protein were selected as gene segments and cloned into expression vector pET32a (+) after amplified by PCR. The protein expressed was analyzed by SDS-PAGE, after the recombinant plasmid transformed into E. coli BL21 (DE3) plys. Balb/c mice were immunized with the recombinant protein purified by nickel metal chelate affinity column. The humoral immune activity of recombinant proteins was detected by Western blotting and indirect ELISA. The cellular immune activity was detected by flow cytometry and sandwich ELISA. Results The fusion protein about 22 kDa was obtained. Western blotting test showed that the multiclonal antibody for HCMV has specificity and the titers reach to 1:102400 detected by indirected ELISA. The number of CD4+ T cells and CD8+ T cells in peripheral blood and the quantities of IFN-γ, IL-2, IL-12 were significantly higher than control group (P<0.01). Conclusions The recombinant protein with dominant antigen epitopes can induce significant humoral immunity and cellular immunity in mice, and is a potential vaccine for HCMV.
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