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Identification and characterization of camptothecin tailoring enzymes in Nothapodytes tomentosa

Journal of Integrative Plant Biology 2024年第6期66卷 1158-1169页

作者： Yin Chen Jian-Ping Huang Yong-Jiang Wang Meng-Ling Tu Junheng Li Bingyan Xu Guoqing Peng Jing Yang Sheng-Xiong Huang State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory for economic Plants and Biotechnology Kunming Institute of Botany Chinese Academy of Sciences

Camptothecin is a complex monoterpenoid indole alkaloid with remarkable antitumor activity. Given that two C-10 modified camptothecin derivatives,topotecan and irinotecan, have been approved as potent anticancer agents, there is a critical need for methods to access other aromatic ringfunctionalized congeners(e.g., C-9, C-10, etc.).However, contemporary methods for chemical oxidation are generally harsh and low-yielding when applied to the camptothecin scaffold, thereby limiting the development of modified derivatives. Reported herein, we have identified four tailoring enzymes responsible for C-9 modifications of camptothecin from Nothapodytes tomentosa, via metabolomic and transcriptomic analysis. These consist of a cytochrome P450(Nt CPT9H) which catalyzes the regioselective oxidation of camptothecin to 9-hydroxycamptothecin, as well as two methyltransferases(Nt OMT1/2, converting 9-hydroxycamptothecin to 9-methoxycamptothecin),and a uridine diphosphate-glycosyltransferase(Nt UGT5, decorating 9-hydroxycamptothecin to9-β-D-glucosyloxycamptothecin). Importantly, the critical residues that contribute to the specific catalytic activity of Nt CPT9H have been elucidated through molecular docking and mutagenesis experiments. This work provides a genetic basis for producing camptothecin derivatives through metabolic engineering. This will hasten the discovery of novel C-9 modified camptothecin derivatives,with profound implications for pharmaceutical manufacture.

关键词： camptothecin biosynthesis enzymatic assay Nothapodytes tomentosa tailoring enzyme transcriptomic analysis

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Local State Capacity and Uneven Taxation across Industrial Firms

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China & World Economy 2024年第3期32卷 191-214页

作者： Linke Hou Zhikuo Liu Qi Zhang Xiaolu Zhao the economic Research center Shandong UniversityChina China center for economic Studies Fudan UniversityChina School of economics Ocean University of ChinaChina

In this research we investigate the association between local state capacity(LSC)and effective tax burdens(ETBs)on industrial firms within counties between 1998 and 2013.The LSC measures a state's capacity for policy implementation and specifically its ability to acquire low-cost agricultural land for nonagricultural(industrial or commercial)purposes.Based on China's government-led development experience since the 1990s,we draw on two unique household survey datasets to capture LSC at county level.We find robust evidence that greater LSC was associated with much lower ETBs on large industrial firms.This taxation pattern implies local government's primary reliance on larger manufacturing firms,while the ETBs for small-and-medium enterprises are not as prominently addressed.This research highlights that LSC can affect both the amount of revenue a local government can generate and the methods it uses to collect these revenues.

关键词： China effective tax burdens land requisition local government local state capacity

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Large-scale interplant exchange of macromolecules between soybean and dodder under nutrient stresses

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Plant Diversity 2024年第1期46卷 116-125页

作者： Jingxiong Zhang Shalan Li Wenxing Li Zerui Feng Shuhan Zhang Xijie Zheng Yuxing Xu Guojing Shen Man Zhao Guoyan Cao Xuna Wu Jianqiang Wu Department of economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant ResourcesKunming Institute of BotanyChinese Academy of SciencesKunming 650201China CAS center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan and center for Life Science School of Life SciencesYunnan UniversityKunming 650500China

Parasitic plants and their hosts communicate through haustorial connections.Nutrient deficiency is a common stress for plants,yet little is known about whether and how host plants and parasites communicate during adaptation to such nutrient stresses.In this study,we used transcriptomics and proteomics to analyze how soybean(Glycine max)and its parasitizing dodder(Cuscuta australis)respond to nitrate and phosphate deficiency(-N and-P).After-N and-P treatment,the soybean and dodder plants exhibited substantial changes of transcriptome and proteome,although soybean plants showed very few transcriptional responses to-P and dodder did not show any transcriptional changes to either-N or-P.Importantly,large-scale interplant transport of mRNAs and proteins was detected.Although the mobile mRNAs only comprised at most 0.2%of the transcriptomes,the foreign mobile proteins could reach 6.8%of the total proteins,suggesting that proteins may be the major forms of interplant communications.Furthermore,the interplant mobility of macromolecules was specifically affected by the nutrient regimes and the transport of these macromolecules was very likely independently regulated.This study provides new insight into the communication between host plants and parasites under stress conditions.

关键词： Cuscuta Mobile molecules Nutrient deficiency Host plant-parasitic plant interaction Interplant transport Systemic signaling

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The coordinated evolution of ecological environment,public service,and tourism economy along the Silk Road economic Belt,using the Dual-Carbon Targets

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Chinese Journal of Population,Resources and Environment 2024年第1期22卷 34-47页

作者： Shuo Yang Wei Guo Tianjun Xu Tongtong Liu School of economic and Management Yanshan UniversityQinhuangdao 066004China Regional economic Development center Yanshan UniversityQinhuangdao 066004China

Carbon peak and carbon neutrality(dual-carbon)are important targets for the international response to climate change.The Silk Road economic Belt is a strategic resource region and is important for future ecological environment and tourism development.Based on the“dual-carbon”targets,the Single index quantification,Multiple index synthesis,and Poly-criteria integration evaluation model were used in this study to measure the coordinated development index of the ecological environment,public service,and tourism economy along the Silk Road economic Belt and to analyze its spatial and temporal evolution.Further,it explores the dynamic evolution and development trend of the three systems using the Kernel Density and Grey Markov Prediction Model.The results show that the coordinated development index along this region needs to be improved during the study period.Furthermore,the coordinated development index of the Southwest region is relatively higher than that of the Northwest region.From the development trend of the three systems,all of them develop in a stable manner;however,the tourism economy system is easily affected by external disturbances.The coordinated development index of the three systems changes dynamically and tends to be in a good state of coordination.There is a certain spatial and temporal heterogeneity.The gravity center of the coordinated development index has been in the Southwest region.During the forecast period,the coordinated development index along this region will improve significantly,while insufficient and unbalanced development will continue.

关键词： Dual-carbon Ecological environment Public services Tourist economy Silk Road economic Belt

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Optimal scheduling of a township integrated-energy system using the adjustable heat-electricity ratio model

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Global Energy Interconnection 2024年第1期7卷 48-60页

作者： Quan Chen Jingyi Wang Min Cang Xiaomeng Zhai Xi Cheng Shuang Wu Dongwei Li economic and Technology Research Institute of State Grid Jiangsu Electric Power Co. LtdNanjing210008P.R.China Power Construction Technical and economic Consulting center of China Electricity Council Beijing100053P.R.China

With the expansion and implementation of rural revitalization strategies,there is a constant need for new energy sources for the construction of new townships.Consequently,integrated energy systems with the interconnection and interaction of multiple energy sources are developing rapidly.Biomass energy,a renewable green energy source with low pollution and wide distribution,has significant application potential in integrated energy systems.Considering the application of biomass energy in townships,this study established an integrated biomass energy system and proposed a model to optimize its operation.Lowest economic cost and highest clean energy utilization rate were considered as the objective functions.In addition,a plan was suggested to adjust the heat-electricity ratio based on the characteristics of the combined heat and power of the biomass.Finally,a simulation analysis conducted for a town in China was discussed,demonstrating that the construction of a township integrated-energy system and the use of biomass can significantly reduce operating costs and improve the energy utilization rate.Moreover,by adjusting the heat-electricity ratio,the economic cost was further reduced by 6.70%,whereas the clean energy utilization rate was increased by 5.14%.

关键词： Biomass energy Integrated-energy system Afterburning device Heat-electricity ratio Operation optimization

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Eco-evolutionary evidence for the global diversity pattern of Cycas(Cycadaceae)

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Journal of Integrative Plant Biology 2024年第6期66卷 1170-1191页

作者： Jian Liu Anders J.Lindstrom Yiqing Gong Shanshan Dong Yusheng(Chris) Liu Shouzhou Zhang Xun Gong CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Department of economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of BotanyChinese Academy of Sciences University of Chinese Academy of Sciences Global Biodiversity Conservancy Key Laboratory of Southern Subtropical Plant Diversity Fairy Lake Botanical Garden Shenzhen & Chinese Academy of Sciences Department of Earth and Environmental Sciences Indiana University-Indianapolis

The evolution of the latitudinal diversity gradient(LDG), characterized by a peak in diversity toward the tropics, has captured significant attention in evolutionary biology and ecology.However, the inverse LDG(i-LDG) mechanism,wherein species richness increases toward the poles, remains inadequately explored. Cycads are among one of the oldest lineages of extant seed plants and have undergone extensive diversification in the tropics. Intriguingly, the extant cycad abundance exhibits an i-LDG pattern, and the underlying causes for this phenomenon remain largely elusive. Here,using 1,843 nuclear genes from a nearly complete sampling, we conducted comprehensive phylogenomic analyses to establish a robust species-level phylogeny for Cycas, the largest genus within cycads. We then reconstructed the spatial-temporal dynamics and integrated global environmental data to evaluate the roles of species ages, diversification rates,contemporary environment, and conservatism to ancestral niches in shaping the i-LDG pattern. We found Cycas experienced decreased diversification rates, coupled with the cooling temperature since its origin in the Eocene from continental Asia. Different regions have distinctively contributed to the formation of i-LDG for Cycas, with the northern hemisphere acting as evolutionary museums and the southern hemisphere serving as cradles. Moreover, water-related climate variables,specifically precipitation seasonality and potential evapotranspiration, were identified as paramount factors constraining Cycas species richness in the rainforest biome near the equator. Notably, the adherence to ancestral monsoonal climates emerges as a critical factor in sustaining the diversity pattern. This study underscores the imperative of integrating both evolutionary and ecological approaches to comprehensively unravel the mechanisms underpinning global biodiversity patterns.

关键词： cycads latitudinal diversity gradient niche conservatism spatiotemporal diversification species richness

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Impact of carbon disclosure on debt financing costs

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Chinese Journal of Population,Resources and Environment 2024年第1期22卷 98-108页

作者： Yiming Hu Yunfeng Liang School of Management and economics Beijing Institute of TechnologyBeijing 100081China China center for International economic Exchanges Beijing 100050China

Creditors,such as banks,often use disclosed environmental information to assess a company’s environmental risk and ensure the safety of debt funds.Consequently,carbon disclosures have become an important consideration for creditors when making investments.This study explores the relationship between carbon disclosure and debt financing costs using data on listed companies from 2008 to 2019.The results show that carbon disclosure can reduce the debt financing costs of enterprises,and that this influence is more significant for private companies than for state-owned enterprises.Instrumental variables and Propensity Score Matching(PSM)were used to evaluate the robustness of negative relationships.Furthermore,carbon disclosure has a more significant impact on debt costs with less environmental supervision pressure,weak residents’environmental awareness,and weak product market competition.These findings provide guidance for companies’carbon information disclosure and support the establishment of official carbon disclosure standards.

关键词： Carbon disclosure Debt financing cost State-owned enterprise Private enterprise

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A Structural Measurement of the Valuation Effect of China's External Assets:Method and Application

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China & World Economy 2024年第2期32卷 97-124页

作者： Guowei Cai Xiaowei Chen Xun Wang Lingnan College Sun Yat-sen UniversityChina China center for economic Research National School of DevelopmentPeking UniversityChina

Existing research on the measurement of the valuation effect mainly follows the residual method proposed by Lane and Milesi-Ferretti(2001).This cannot be used to perform structural decomposition.We propose an aggregation approach rather than the residual method to measure structurally the investment flow and valuation effect of China's external assets.The results indicate that the valuation effect of China's external assets has been highly volatile and it was negative during the pandemic period.The structural decomposition shows that portfolio investment and direct investment made the main contributions to the valuation effect.The impact of exchange rates on the valuation effect has generally been higher than that of asset price in terms of direct investment and total external assets but the opposite has been true for portfolio investment.China's outward investments are currently more inclined to Asian countries and a few European countries but inflows to China still mainly come from developed countries.

关键词： external asset investment direction structural measurement valuation effect

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Central Asia revealed as a key area in evolution of Eremurus (Asphodelaceae)

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Plant Diversity 2024年第3期46卷 333-343页

作者： Dilmurod Makhmudjanov Sergei Volis Ziyoviddin Yusupov Inom Juramurodov Komiljon Tojibaev Tao Deng Hang Sun CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina Yunnan International Joint Laboratory for Biodiversity of Central Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina Institute of botany Academy Sciences of UzbekistanTashkent 100125Uzbekistan University of Chinese Academy of Sciences Beijing 100864China

Eremurus was described at the beginning of the 19th century.However,due to limited sampling and the small number of gene markers to date,its phylogeny and evolution are largely unknown.In this study,we analyzed plastomes from 27 species belonging to 2 subgenera and 3 sections of Eremurus,which are found in Central Asia(its center of diversity)and China.We also analyzed nuclear DNA ITS of 33 species,encompassing all subgenera and sections of the genus in Central Asia,southwest Asia and China.Our findings revealed that the genus was monophyletic,although both subgenera Eremurus and Henningia were found to be paraphyletic.Both plastome and nrDNA-based phylogenetic trees had three clades that did not reflect the current taxonomy of the genus.Our biogeographical and time-calibrated trees suggest that Eremurus originated in the ancient Tethyan area in the second half of the Eocene.Diversification of Eremurus occurred from the early Oligocene to the late Miocene.Paratethys Sea retreat and several orogenetic events,such as the progressive uplift of the Qinghai-Tibet Plateau and surrounding mountain belts(Altai,Pamir,Tian Shan),caused serious topographic and climate(aridification)changes in Central Asia that may have triggered a split of clades and speciation.In this transformed Central Asia,speciation proceeded rapidly driven mainly by vicariance caused by numerous mountain chains and specialization to a variety of climatic,topographic and soil conditions that exist in this region.

关键词： Asphodelaceae Asphodeloideae Plastome Central Asia Qinghai-Tibet Plateau

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AtVQ25 promotes salicylic acid-related leaf senescence by fine-tuning the self-repression of AtWRKY53

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Journal of Integrative Plant Biology 2024年第6期66卷 1126-1147页

作者： Qi Tan Mingming Zhao Jingwei Gao Ke Li Mengwei Zhang Yunjia Li Zeting Liu Yujia Song Xiaoyue Lu Zhengge Zhu Rongcheng Lin Pengcheng Yin Chunjiang Zhou Geng Wang Ministry of Education Key Laboratory of Molecular and Cellular Biology Hebei Research Center of the Basic Discipline of Cell BiologyHebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation Hebei Key Laboratory of Molecular and Cellular Biology College of Life Sciences Hebei Normal University College of Chemical Engineering Shijiazhuang University Institute of botany Chinese Academy of Sciences

Most mechanistic details of chronologically ordered regulation of leaf senescence are unknown.Regulatory networks centered on AtWRKY53 are crucial for orchestrating and integrating various senescence-related signals. Notably, AtWRKY53binds to its own promoter and represses transcription of AtWRKY53, but the biological significance and mechanism underlying this selfrepression remain unclear. In this study, we identified the VQ motif-containing protein AtVQ25as a cooperator of AtWRKY53. The expression level of AtVQ25 peaked at mature stage and was specifically repressed after the onset of leaf senescence. AtVQ25-overexpressing plants and atvq25 mutants displayed precocious and delayed leaf senescence, respectively. Importantly, we identified AtWRKY53 as an interacting partner of AtVQ25. We determined that interaction between AtVQ25 and AtWRKY53 prevented AtWRKY53from binding to W-box elements on the AtWRKY53promoter and thus counteracted the selfrepression of AtWRKY53. In addition, our RNA-sequencing data revealed that the AtVQ25-AtWRKY53 module is related to the salicylic acid(SA) pathway. Precocious leaf senescence and SA-induced leaf senescence in AtVQ25-overexpressing lines were inhibited by an SA pathway mutant, atsid2, and Nah G transgenic plants; AtVQ25-overexpressing/atwrky53 plants were also insensitive to SA-induced leaf senescence. Collectively, we demonstrated that AtVQ25 directly attenuates the self-repression of AtWRKY53 during the onset of leaf senescence,which is substantially helpful for understanding the timing of leaf senescence onset modulated by AtWRKY53.

关键词： AtWRKY53 leaf senescence salicylic acid transcriptional regulation VQ motif-containing proteins

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