作者机构：
[Liu, Tianzhi] Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410018, Peoples R China.;[He, Jiawen; Luo, Fen] Cent South Univ Forestry & Technol, Coll Tourism, Changsha 410018, Peoples R China.
通讯机构：
[Fen Luo] C;College of Tourism, Central South University of Forestry and Technology, Changsha 410018, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
tourist flows;network structure;evolution
摘要：
Transportation facilitates the flow of tourists generating tourist flows, which produce flow effects on the spatial scale. By analyzing the evolution of tourist flows in Zhangjiajie by various modes of transportation over a long time series, the results show that the degree of development of the destination transportation network affects the dominance of the tourism node. Specifically, in the “train period”, Zhangjiajie, Changsha, Fenghuang, and Jishou core destinations become dominant with the “Matthew Effect”. In the “road period”, Jishou and Mengdonghe destinations decline, with the “Filtering Effect”. In the “high-speed railway period”, Zhangjiajie and Changsha are connected with more distant origins, and the “Diffusion Effect” occurs. It is worth noting that the development of high-speed rail has created a substitution effect for trains over long distances, and self-driving has created a substitution effect for trains over short and medium distances.
关键词：
transcriptome;Paeonia suffruticosa;embryo abortion;phytohormone;the gene common expression trend
摘要：
Peonies are significant ornamental plants that are primarily propagated through distant cross-breeding to create new varieties. However, hybrid failure is a critical issue that impedes the advancement of breeding. Numerous studies have demonstrated that endogenous hormones in the seed embryo constitute a significant factor in embryo failure. Nevertheless, it is still unknown how plant hormones control the development of peony embryos at the molecular level. In this study, we characterized the endogenous hormone levels in peony seeds of hybrid-aborted, hybrid-normal, and self-crossing normal after 26 days of pollination (DAP). Our findings show that the hybrid-aborted embryos had significantly higher amounts of ABA, IAA, and GA. In addition, the ratio of GA+IAA/ABA was lower than that of the hybrid-normal seeds and higher than that of the self-crossing normal seeds. To further investigate the mechanism of hormone control on peony embryo development, we conducted a transcriptome sequencing analysis of the three seed types. Results revealed that differentially expressed genes involved in phytohormone metabolism and signal transduction significantly enriched the aborted embryos. Furthermore, we examined the expression levels of six hormones in different seeds and used the Gene Common Expression Trend analysis to analyze genes highly correlated with phytohormone in the KEGG pathway. We used protein interaction networks to explore the interactions between proteins in the hormone pathway in aborted embryos. Then we identified key genes and transcription factors (TFs) such as Abscisic acid-insensitive 5 (ABI5), Auxin Response Factor 5 (ARF5), Gibberellin Insensitive Dwarf 1 (GID1), Arabidopsis Response Regulator4 (ARR4), Jasmonate-zim-domain protein 1 (JAZ1), Brassinazole-resistant 1 (BZR1), etc., whose functions require further investigation. Our findings establish a foundation for the metabolic regulation of peony hybrid embryo abortion via networks regulating phytohormone signaling. However, further research is needed to determine the exact mechanisms by which hormones regulate peony embryo development and to explore new methods for improving the success rate of hybridization.
通讯机构：
[Liu, JA ; Zhou, GY] C;Cent South Univ Forestry & Technol, Key Lab, Natl Forestry & Grassland Adm Control Dis & Pests, Changsha 410004, Peoples R China.;Cent South Univ Forestry & Technol, Hunan Prov Key Lab Control Forest Dis & Pests, Changsha 410004, Peoples R China.;Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Changsha 410004, Peoples R China.
关键词：
pine wilt disease;nematicidal bacteria;defense enzyme activity;biocontrol
摘要：
Pine Wilt Disease (PWD), caused by the pathogenic nematode Bursaphelenchus xylophilus, is a systemic infectious disease commonly referred to as the “cancer” of pine trees. This devastating disease has gained this analogy due to its ability to rapidly spread within pine populations, leading to substantial losses in forest resources. The primary objective of this study is to investigate the bioprotective potential and underlying mechanisms of action exhibited by rhizosphere microorganisms associated with Masson pine (Pinus massoniana) in the context of controlling the pine wilt nematode. In this experiment, using high-throughput sequencing, significant differences were observed in the rhizosphere soil microbial communities among healthy Masson pine, standing dead trees, and diseased Masson pine. Furthermore, it was found that these microbial communities exhibited distinct community structures at different levels. This study successfully isolated and screened three strains of highly effective nematophagous bacteria from the rhizosphere soil. The identified strains were Lysinibacillus capsici, Bacillus Paramycoides, and Delftia tsuruhatensis. After applying the bacterial suspensions and fermentation extracts of these three strains to the roots of two-year-old Masson pine seedlings, followed by inoculation with pine wilt nematodes after a four-day period, distinct defense responses were observed in the Masson pine. Notably, the activities of phenylalanine ammonia-lyase (PAL) and peroxidase (POD) were significantly increased, leading to a substantial reduction in the incidence of pine wilt disease. Based on the changes in defense enzyme activities, it can be concluded that the fermentation extract of the Lysinibacillus capsici strain exhibits effective nematocidal effects and induces resistance. The significant biological control efficacy and induction of host defense activity indicate the potential application value of this strain and its metabolites as a biocontrol agent for pine wilt disease.
作者机构：
[Wu, Wenjie] Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410004, Hunan, Peoples R China.;[Li, Cheng; Chen, Guangjie; Feng, Hao; Wu, Wenjie; Feng, H] Northwest A&F Univ, Inst Water Saving Agr Arid Areas China, Yangling 712100, Shaanxi, Peoples R China.;[Feng, Hao; Feng, H; Meng, Tingfang] Chinese Acad Sci, Inst Soil & Water Conservat, Yangling 712100, Shaanxi, Peoples R China.;[Feng, Hao; Feng, H; Meng, Tingfang] Minist Water Resources, Yangling 712100, Shaanxi, Peoples R China.;[Si, Bingcheng] Univ Saskatchewan, Dept Soil Sci, Saskatoon, SK S7N5A8, Canada.
通讯机构：
[Feng, H ] N;[Si, BC ] U;Northwest A&F Univ, Inst Water Saving Agr Arid Areas China, Yangling 712100, Shaanxi, Peoples R China.;Chinese Acad Sci, Inst Soil & Water Conservat, Yangling 712100, Shaanxi, Peoples R China.;Minist Water Resources, Yangling 712100, Shaanxi, Peoples R China.
关键词：
Aggregate stability;Root distribution;Soil organic carbon;Soil physical property;Soil water content
摘要：
BackgroundIn seed plants, the ovule is the precursor to the seed. The process of ovule development and differentiation is regulated by multiple factors, including starch metabolism and endogenous hormones. Castanea henryi produces nuts with high nutritional value. However, the high proportion of empty buds restricts the commercial use of the tree. Previous studies have shown that the empty bud phenotype is closely related to ovule abortion. If none of the ovules in the ovary expand rapidly and develop in 7-8 weeks after pollination, an empty bud will form. Therefore, we studied the development and molecular mechanisms underlying single seed formation in C. henryi.ResultsWe found that 49 days after pollination (DAP) is a critical period for the formation of fertile and abortive ovules. The morphology and starch distribution of the fertile and abortive ovules differed significantly at 49 DAP. The fertile ovules were smooth and round in appearance, with a large amount of starch. In contrast, abortive ovules were smaller with only a small amount of starch. The embryo sac of the abortive ovule proceeded to develop abnormally, and the entire ovule lacked starch. We identified 37 candidate genes involved in metabolism with potential roles in the regulation of starch levels. Three ADP-glucose pyrophosphorylase (AGPase) genes, one granule-bound starch synthase (GBSS) gene, and two beta-amylase genes could affect starch accumulation. The levels of auxin, cytokinins, gibberellins, and jasmonic acid in fertile ovules were higher than those in abortive ovules. In addition, the levels of endogenous abscisic acid and salicylic acid in abortive ovules were higher than those in fertile ovules of the same age, consistent with the expression patterns of genes related to the synthesis of abscisic and salicylic acid and signal transduction. We identified and mapped the differentially expressed genes associated with hormone synthesis and signal transduction.ConclusionsThese results improve our general understanding of the molecular mechanisms underlying single seed development in C. henryi and the phenomenon of empty buds, providing directions for future research.
通讯机构：
[Gui Zhang] A;Author to whom correspondence should be addressed.<&wdkj&>College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China
关键词：
Himawari-8 image;smoke detection;sub-pixel mapping;random forest;forest fire monitoring
通讯机构：
[Wei Zhang; Zhongcheng Wang] A;Authors to whom correspondence should be addressed.<&wdkj&>Forestry College, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, China<&wdkj&>Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China<&wdkj&>Guangxi Key Laboratory of Karst Ecological Processes and Services, Huanjiang 547100, China
摘要：
【目的】氮沉降是影响森林凋落物分解的因素之一，为探究氮添加对杉木-闽楠混交林凋落叶分解过程的影响，采用尼龙网袋法对永州荆竹林场杉木闽楠混交林中杉木和闽楠凋落叶分别进行原位分解试验。【方法】研究不同的氮添加浓度[N0:0 g N/（m~2·a）;N1:7 g N/（m~2·a）;N2:14 g N/（m~2·a）;N3:28 g N/（m~2·a）;N4:56 g N/（m~2·a）]对杉木闽楠混交林凋落叶分解过程中基质质量的影响。【结果】（1）经过1年的分解，两树种的质量损失均随着氮添加浓度上升而呈减少的趋势，氮添加对杉木和闽楠凋落叶的分解均有显著的抑制作用，并随着氮浓度的增加，抑制作用越明显。氮添加处理使得杉木凋落叶质量损失95%的时间，在4.88年的基础上增加了0.83～1.72年，闽楠凋落叶质量损失95%的时间，在5.08年的基础上增加了0.20～1.45年。（2）杉木和闽楠凋落叶中木质素和纤维素含量较高，占凋落叶质量的50%以上，N0和N1处理下杉木的凋落物质量残留率分别与纤维素和木质素呈显著正相关，N0和N2处理下闽楠的凋落物质量残留率与纤维素含量呈显著正相关，氮添加增加了杉木和闽楠凋落叶中木质素的含量，抑制了凋落物分解，不同浓度的氮添加处理对杉木和闽楠凋落叶的分解作用存在差异。（3）同一氮添加浓度下，闽楠凋落叶的质量损失和分解速率大于杉木。【结论】凋落叶质量残留率与基质质量具有显著相关性，基质质量在一定程度上会影响凋落物的分解。
摘要：
Fat storage and weight gain are dominant traits for hibernating mammals. However, excessive fat accumulation may cause liver damage. Here, we explore the lipid accumulation and metabolic processes of the Himalayan marmot (Marmota himalayana), a hibernating rodent species. We find that the unsaturated fatty acid (UFA) content in food was consistent with a large increase in the body mass of Himalayan marmots. Metagenomic analysis shows that Firmicutes Bacterium CAG:110 plays a synergistic role by synthesizing UFAs, which is demonstrated by fecal transplantation experiments, indicating that the gut microbiome promotes fat storage in Himalayan marmots for hibernation. Microscopic examination results indicate that the risk of fatty liver appears at maximum weight; however, liver function is not affected. Upregulations of UFA catabolism and insulin-like growth factor binding protein genes provide an entry point for avoiding liver injury.
期刊：
European Journal of Forest Research,2023年142(6):1369-1383 ISSN：1612-4669
通讯作者：
Wu, LC;Du, A
作者机构：
[Wu, Lichao; Wang, Zhengye; Chen, Lijun; Wang, Zhong] Cent South Univ Forestry & Technol, Key Lab Soil & Water Conservat & Desertificat Comb, Changsha 410004, Hunan, Peoples R China.;[Wu, Lichao; Wang, Zhengye; Chen, Lijun; Wang, Zhong] Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Minist Educ, Changsha 410004, Hunan, Peoples R China.;[Du, Apeng; Wang, Zhichao; Zhu, Wankuan; Du, A; Wang, Zhong; Xu, Yuxing] Chinese Acad Forestry CAF, Res Inst Fast Growing Trees RIFT, Zhanjiang 524022, Guangdong, Peoples R China.;[He, Chun] Gaofeng State Owned Forest Farm Guangxi Zhuang Aut, Nanning 530001, Guangxi, Peoples R China.
通讯机构：
[Wu, LC ; Du, A ] C;Cent South Univ Forestry & Technol, Key Lab Soil & Water Conservat & Desertificat Comb, Changsha 410004, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Minist Educ, Changsha 410004, Hunan, Peoples R China.;Chinese Acad Forestry CAF, Res Inst Fast Growing Trees RIFT, Zhanjiang 524022, Guangdong, Peoples R China.
关键词：
Eucalyptus plantation;Native species;Soil bacterial community and functions;Relationships in soil nutrients and bacteria
摘要：
The introduction of native tree species can enhance soil ecological functions and mitigate the decline in soil status triggered by the high-intensity monoculture of Eucalyptus plantations, but the specific impact is still unclear. In this study, differences in the structural and function for soil bacterial communities were investigated between evergreen broad-leaved secondary forests, Eucalyptus pure plantations, and mixed plantations of Eucalyptus with two native species in Guangxi: Manglietia glauca and Mytilaria laosensis, respectively. Additionally, soil physicochemical properties and enzyme activities were determined. The results showed that pH, soil sucrase and peroxidase activities, and bacterial alpha-diversity indices were significantly higher in Eucalyptus mixed plantations with M. glauca and M. laosensis, compared to Eucalyptus pure plantations. Bacterial biomarkers (Burkholderiales, Bradyrhizobium, and Actinobacteria) with nitrogen fixation and phosphate solubilization functions were enriched in Eucalyptus with M. glauca and M. laosensis. Redundancy analysis showed that pH, effective boron (AB), and soil moisture were the main soil environmental factors driving changes in the structure of the soil bacterial community. Thus, we concluded that mixed plantations of Eucalyptus with M. glauca or M. laosensis have positive effects on mitigating soil acidification, increasing soil enzymatic activity, and improving soil ecological functions, which provides useful information for the development of sustainable management of Eucalyptus plantations.
作者：
Chen, Zhaojun;Zhang, Meng;Zhang, Huaiqing;Liu, Yang
期刊：
IEEE Transactions on Geoscience and Remote Sensing,2023年61:1-11 ISSN：0196-2892
作者机构：
[Zhang, Huaiqing; Liu, Yang] Research Institute of Forest Resources Information Techniques, Chinese Academy of Forestry, Beijing, China;[Chen, Zhaojun; Zhang, Meng] College of Forestry, Central South University of Forestry and Technology, Changsha, China
摘要：
Mangrove forests are among the most productive of coastal ecosystems, providing a variety of ecological functions and economic value to coastal areas around the world. Accurate identification of mangrove is of great importance for the restoration and conservation of mangrove ecosystems and for promoting the development of a blue carbon economy and achieving carbon-neutral strategies. In this study, a red-edge mangrove index (REMI) was proposed based on Sentinel-2 multispectral images, using red, green, red edge, and SWIR1 bands in the form of a (red edge-red)/(SWIR1-green) combination to highlight the unique green and moisture information of mangrove. Then, the REMI index was combined with the Otsu threshold segmentation algorithm (Otsu) to map the mangrove information with respect to Hainan Island, which has the most abundant mangrove species in China. The results indicate that, when compared with other vegetation indices, such as the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), mangrove index (MI), normalized difference MI (NDMI), combined mangrove recognition index (CMRI), and mangrove vegetation index (MVI), the REMI showed greater proficiency in distinguishing mangrove from other vegetation. When the REMI was applied to mangrove mapping in Hainan Island, the overall accuracy (OA) and kappa coefficient were 95.68% and 0.92, respectively. In addition, the mangrove distribution ranges mapped in this study were compared with existing mangrove products [HGMF_2020 and China National Standard GB/T 7714–2015 (note)], and it was demonstrated that the mangrove distribution ranges identified based on the REMI had high coincidence with the above-mentioned mangrove products. This proves that the REMI has good potential for application in mangrove identification and mapping.
摘要：
Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is an accurate method for quantifying gene expression levels. Choosing appropriate reference genes to normalize the data is essential for reducing errors. Gelsemium elegans is a highly poisonous but important medicinal plant used for analgesic and anti-swelling purposes. Gelsenicine is one of the vital active ingredients, and its biosynthesis pathway remains to be determined. In this study, G. elegans leaf tissue with and without the application of one of four hormones (SA, MeJA, ETH, and ABA) known to affect gelsenicine synthesis, was analyzed using ten candidate reference genes. The gene stability was evaluated using GeNorm, NormFinder, BestKeeper, ∆CT, and RefFinder. The results showed that the optimal stable reference genes varied among the different treatments and that at least two reference genes were required for accurate quantification. The expression patterns of 15 genes related to the gelsenicine upstream biosynthesis pathway was determined by RT-qPCR using the relevant reference genes identified. Three genes 8-HGO, LAMT, and STR, were found to have a strong correlation with the amount of gelsenicine measured in the different samples. This research is the first study to examine the reference genes of G. elegans under different hormone treatments and will be useful for future molecular analyses of this medically important plant species.
作者机构：
[Zhang, Youming; Li, Ruijuan; Zheng, Wentao; Wang, Xue; Jiang, Chanjuan; Li, RJ; Fu, Jun; Fu, J; Gao, Shiqing; Tu, Qiang; Ravichandran, Vinothkannan] Shandong Univ, State Key Lab Microbial Technol, Qingdao, Peoples R China.;[Zhou, Diao; Yin, Yulong; Xia, Yandong; Yin, Jia] Hunan Normal Univ, Coll Life Sci, Hunan Prov Key Lab Anim Intestinal Funct & Regulat, Hunan Int Joint Lab Anim Intestinal Ecol & Hlth, Changsha 410081, Peoples R China.;[Xia, Yandong] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Key Lab Natl Forestry Grassland & Adm Control Arti, Hunan Prov Key Lab Control Forest Dis & Pests,Key, Changsha, Peoples R China.;[Zhang, Youming; Tu, Qiang] Chinese Acad Sci, Shenzhen Inst Synthet Biol, Shenzhen Inst Adv Technol, CAS Key Lab Quantitat Engn Biol, Shenzhen, Peoples R China.
通讯机构：
[Yin, J ] H;[Li, RJ ; Fu, J] S;Shandong Univ, State Key Lab Microbial Technol, Qingdao, Peoples R China.;Hunan Normal Univ, Coll Life Sci, Hunan Prov Key Lab Anim Intestinal Funct & Regulat, Hunan Int Joint Lab Anim Intestinal Ecol & Hlth, Changsha 410081, Peoples R China.
摘要：
A lack of generic and effective genetic manipulation methods for Pseudomonas has restricted fundamental research and utilization of this genus for biotechnology applications. Phage-encoded homologous recombination (PEHR) is an efficient tool for bacterial genome engineering. This PEHR system is based on a lambda Red-like operon (BAS) from Pseudomonas aeruginosa phage Ab31 and a Rac bacteriophage RecET-like operon (Rec-TEPsy) from P. syringae pv. syringae B728a and also contains exogenous elements, including the RecBCD inhibitor (Redγ or Pluγ) or single-stranded DNA-binding protein (SSB), that were added to enhance the PEHR recombineering efficiency. To solve the problem of false positives in Pseudomonas editing with the PEHR system, the processive enzyme Cas3 with a minimal Type I-C Cascade-based system was combined with PEHR. This protocol describes the utilization of a Pseudomonas-specific PEHR–Cas3 system that was designed to universally and proficiently modify the genomes of Pseudomonas species. The pipeline uses standardized cassettes combined with the concerted use of SacB counterselection and Cre site-specific recombinase for markerless or seamless genome modification, in association with vectors that possess the selectively replicating template R6K to minimize recombineering background. Compared with the traditional allelic exchange editing method, the PEHR–Cas3 system does not need to construct suicide plasmids carrying long homologous arms, thus simplifying the experimental procedure and shortening the traceless editing period. Compared with general editing systems based on phage recombinases, the PEHR–Cas3 system can effectively improve the screening efficiency of mutants using the cutting ability of Cas3 protein. The entire procedure requires ~12 days. This protocol for universal and proficient Pseudomonas recombineering uses phage-encoded homologous recombination–Cas3 systems, including SacB counterselection and Cre site-specific recombinase for two- or three-step seamless genome modification.
