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Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-Cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-1. to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

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Characterization of photosynthesis,photoinhibition and the activities of C_4 pathway enzymes in a superhigh-yield rice,Liangyoupeijiu

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Science China(Life Sciences) 2002年第5期45卷 468-476页

作者：王强郝迺斌白克智卢从明戈巧英匡廷云张其德董凤琴 1. Laboratory of Photosynthesis Basic Research Institute of Botany Chinese Academy of Sciences 100093 Beijing China

Characteristics of photosynthetic gas exchange, photoinhibition and C4 pathway enzyme activities in both flag leaves and lemma were compared between a superhigh-yield rice (Oryza sativa L.) hybrid, Liangyoupeijiu and a traditional rice hybrid, Shanyou63. Liangyoupeijiu had a similar light saturated assimilation rate (Asat) to Shanyou63, but a much higher apparent quantum yield (AQY), carboxylation efficiency (CE) and quantum yield of CO2 fixation (φCO2). Liangyoupeijiu also showed a higher resistance to photoinhibition and higher non-radiative energy dissipation associated with the xanthophyll cycle than Shanyou63 when subjected to strong light. In addition, Liangyoupeijiu had higher activities of the C4 pathway enzymes in both flag leaves and lemmas than Shanyou63. These results indicate that higher light and CO2 use efficiency, higher resistance to photoinhibition and C4 pathway in both flag leaf and lemma may contribute to the higher yield of the superhigh-yield rice hybrid, Liangyoupeijiu.

关键词： superhigh-yield hybrid rice, photosynthesis, photoinhibition, C4 pathway.

High-nitrogen and low-irradiance can restrict energy utilization in photosynthesis of successional tree species in low subtropical forest

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Science China(Life Sciences) 2008年第7期51卷 592-603页

作者： CAI Xi’An,SUN GuChou,ZHAO Ping &LIU XiaoJing South China institute of {1.,Chinese Academy of Sciences,Guangzhou 51.650,China 1. South China institute of {1. Chinese Academy of Sciences Guangzhou 510650 China

Responses of photosynthesis and the partition of energy utilization to high-nitrogen importation and high-light intensity in leaves of three dominant tree species of subtropical forest,including sun plant or early-successional species Schima superba,mesophyte or intermediate-successional species Canstanopsis hystrix,and shading-tolerant plant or late-successional species Cryptocarya concinna were studied by using the CO2 exchange system and chlorophyll fluorescence *** results showed that,regardless of plant species,net photosynthetic rate(Pn)was higher in high-nitrogen supply and high irradiance(HNHL)plants than in low-nitrogen supply and high irradiance(LNHL)plants,implying that low-nitrogen importation would limit Pn of plants grown under high ***, high-nitrogen supply and low irradiance(HNLL)plants had a lower *** change of quantum yield(Fv′/Fm′)in opened PS II was found in leaves of HNHL,LNHL or HNLL plants of *** and C. hystrix,while a higher Fv′/Fm′occurred in HNHL plants of *** in comparison with LNHL or HNLL *** HNHL plants of *** also had a higher photochemical quantum yield(△F/Fm′) than LNHL or HNLL plants,however no similar responses were found in plants of *** and C. hystrix(P1.the fraction of energy consumed by photochemistry(φ PSII )was 1..2%in LNHL plants of *** which was higher than that in HNHL plants(P>0.05)and it was significantly higher than in HNLL plants(P<0.05).*** also had a similar response inφ PSII to nitrogen supply and *** of species HNLL plants had a significantφ PSII and higher heat dissipation in light,and this effect was more severe in *** than in *** or *** results may mean that high-nitrogen importation by nitrogen deposit and low irradiance caused by changing climate or air pollution would more severely restrict photosynthetic processes in the late-succ

关键词： low subtropical forest successional plant high nitrogen concentration partition of photosynthetic energy

Nitrogen addition promotes soil carbon accumulation globally

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Science China Life Sciences 2025年第1期 284-293页

作者： Xuemei Yang Suhui Ma Erhan Huang Danhua Zhang Guoping Chen Jiangling Zhu Chengjun Ji Biao Zhu Lingli Liu Jingyun Fang institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University Ministry of Education Key Laboratory for Transboundary Ecosecurity of Southwest China School of Ecology and Environmental ScienceYunnan University State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences

Soil is the largest carbon(C) reservoir in terrestrial ecosystems and plays a crucial role in regulating the global C cycle and climate *** nitrogen(N) deposition has been widely considered as a critical factor affecting soil organic carbon(SOC) storage, but its effect on SOC components with different stability remains unclear. Here, we analyzed extensive empirical data from 304 sites worldwide to investigate how SOC and its components respond to N addition. Our analysis showed that N addition led to a significant increase in bulk SOC(6.7%), with greater increases in croplands(1..6%) and forests(6.0%) compared to grasslands(2.1.). Regarding SOC components, N addition promoted the accumulation of plant-derived C(9.7%–28.5%) over microbial-derived C(0.2%), as well as labile(5.7%) over recalcitrant components(–1.2%), resulting in a shift towards increased accumulation of plant-derived labile C. Consistently, N addition led to a greater increase in particulate organic C(1..9%) than mineral-associated organic C(3.6%), suggesting that N addition promotes C accumulation across all pools, with more increase in unstable than stable pools. The responses of SOC and its components were best predicted by the N addition rate and net primary productivity. Overall, our findings suggest that N enrichment could promote the accumulation of plant-derived and non-mineral associated C and a subsequent decrease in the overall stability of soil C pool, which underscores the importance of considering the effects of N enrichment on SOC components for a better understanding of C dynamics in soils.

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THE FLORISTIC STRUCTURE OF THE XIZANG PART OF THE QINGHAI-XIZANG PLATEAU PLANT SUBKINGDOM

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Chinese Geographical Science 1991年第3期1卷 27-39页

作者：李恒武素功 1. Kunming institute of {1. Academic Sinica 650204 Kunming PRC

The flora of the Qinghai-Xizang Plateau belongs to the floristic subkingdom of the Holarctic plant kingdom. The Xizang part of this subkingdom can be divided into 4 plant regions. 1. the Yarlung Zangbo River valley region. There are 1.003 species of seed plants, making up 1..38% of the total species in Xizang, and 1.9 endemic species, 1..89% of the total seed plants. The flora originates mainly from the East Himalayas and the Hengduan Mountains. 2) The Tanggute region. There are 349 species of seed plants and 1. endemic species. The flora represents an intermediate one between the Qinghai-Xizang Plateau and the Hengduan Mountains.3) The Qiangtang region. There are 255 species of seed plants and 1. endemic species. The flora derived from the Himalayan flora and mixed with a great number of Tethysian elements. 4) the Ali region. There are 547 species of seed plants and 41.endemic species. The flora seems to be closely related to Tethysian one.

关键词： floristic structure Qinghai-Xizang Plateau plant subkingdom Xizang

Selection and design of high affinity DNA ligands for mutant single-chain derivatives of the bacteriophage 434 repressor

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Science China(Life Sciences) 2001年第3期44卷 274-286页

作者：梁铁兵谭克辉种康朱至清 SándorPongor AndrásSimoncsits 1. institute of botany Chinese Academy of Sciences 100093 Beijing China 2. ICGEB 34012 Trieste Italy

Single-chain repressor RRTRES is a derivative of bacteriophage 434 repressor, which contains covalently dimerized DNA-binding domains (amino acids 1.69) of the phage 434 repressor. In this single-chain molecule, the wild type domain R is connected to the mutant domain RTRES by a recombinant linker in a head-to-tail arrangement. The DNA-contacting amino acids of RTRES at the -1. 1.2, and 5 positions of the α3 helix are T, R, E, S respectively. By using a randomized DNA pool containing the central sequence -CATACAAGAAAGNNNNNNTTT-. a cyclic, in vitro DNA-binding site selection was performed. The selected population was cloned and the individual members were characterized by determining their binding affinities to RRTRES. The results showed that the optimal operators contained the TTAC or TTCC sequences in the underlined positions as above, and that the Kd values were in the 1.1.-1.mol/L1.1.-1.mol/L concentration range. Since the affinity of the natural 434 repressor to its natural operator sites is in the 1.1.-9 mol/L range, the observed binding affinity increase is remarkable. It was also found that binding affinity was strongly affected by the flanking bases of the optimal tetramer binding sites, especially by the base at the 5' position. We constructed a new homodimeric single-chain repressor RrREsRtRES and its DNA-binding specificity was tested by using a series of new operators designed according to the recognition properties previously determined for the RTRES domain. These operators containing the consensus sequence GTAAGAAARNTTACN or GGAAGAAARNTTCCN (R is A or G) were recognized by RTRESRTRES specifically, and with high binding affinity. Thus, by using a combination of random selection and rational design principles, we have discovered novel, high affinity protein-DNA interactions with new specificity. This method can potentially be used to obtain new binding specificity for other DNA-binding proteins.

关键词： binding site selection bacteriophage 434 repressor single-chain repressor protein-DNA interaction protein engineering.

A STUDY ON THE FLORISTIC PLANT GEOGRAPHY OF XISHA ISLANDS, SOUTH CHINA

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Chinese Geographical Science 1994年第3期4卷 232-241页

作者：邢福武李泽贤叶华谷陈炳辉吴德邻 1. South China institute of {1. The Chinese Academy of Sciences 510650 Guangzhou PRC

Xisha Islands is situated on the South China Sea, at 1.° 46'-1.° 08'N. and 1.1. 1.'-1.2 ° 54' E., with an altitude of 2.6-1..9m. The major types of vegetation are the evergreen coral island forest, and beach vegetation. The major types of vegetation are the evergreen coral island forest, scrub forest and beach vegetation. The dominant species of the forest communities are Pisonia grandis, Guettarda speciosa, Scaevola sericea and Messer schmidia *** are 21. species of wild vascularplants belonging to 52 families and 1.7 genera in this area, of which there are 4 families, 4 genera and 5 species of pteridophyte and 48 families, 1.3 genera and 207 species of Angiosperms. The main families of the flora are Poaceae, Papilionaceae, Cyperaceae, Euphorbiaceae, Malvaceae, Rubiaceae, Nyctaginaceae and Boraginaceae etc. According to the geographical distribution, Spermatophytic genera in Xisha Islands may be classified into 9 types, of which pantropic genera accounts for 70% of total genera. At specific level, elements of Tropical Asia to Tropical Australia are dominant part in the forest communities. In this area there is no species endemic to itself. Many primitive taxa such as Gymnosperms, Anonaceae and many others are not found in the flora. Comparing the composition of the flora with those of 6 neighboring regions, the flora of Xisha Islands is quite similar to those of Hainan Island. The similarity indices of genera and species are 98.46% and 94.09% respectively. Indigofera chunianais endemic to the two regions.

关键词： Xisha Islands floristic plant geography

Molecular evidence on maize specific DNA fragment transferred into wheat through sexual hybridization

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Science China(Life Sciences) 1998年第2期41卷 126-132页

作者：陈纯贤朱立煌孙敬三 1. institute of botany Chinese Academy of Sciences 100093 Beijing China 2. institute of Genetics Chinese Academy of Sciences 100101 Beijing China

Nearly 1.0 maize specific repeated DNA clones were screened from a maize random genomic library, and used for RFLP analysis of two wheat DH populations from wheat and maize crosses. The result showed that a maize fragment in clone MR64 was transferred into two wheat DH lines, i.e. No.1. in common wheat DHs and No.1. in persicum wheat DHs, in which strong hybridization signals were detected. It is first proved at DNA level that some maize specific DNA can be transferred into wheat DH progenies through fertilization at low frequency. Sequencing revealed that the size of the cloned insert DNA is 695 bp, containing 58% A+T. Southern hybridization to maize genome with several restriction enzymes indicated that MR64 is a dispersed repeat with 2-3 dominant tandem units. Its sequence structure, methylation pattern, copy number and chromosomal distribution were also determined. The possible mechanism of alien DNA transfer was discussed.

关键词： wheat maize wide crosses doubled haploid (DH) repeated DNA RFLP.

Inheritance and mapping of embryo sac abortion in hybrid between Indica and Japonica rice (Oryza sativa L.)

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Science China(Life Sciences) 1998年第3期41卷 272-277页

作者：刘永胜朱立煌孙敬三沈利爽王玉忠何平陆朝福陈英 1. institute of Genetics Chinese Academy of Sciences 100101 Beijing China 2. institute of {1. Chinese Academy at Sciences 100093 Beijing China

A doubled haploid (DH) population derived from anther culture of F\-1.s between an Indica var. Zhai\|Ye\|Qing 8 and a Japonica var. Jing\|Xi1. as well as two backcross populations derived from this DH population were used to investigate inheritance of the embryo sac abortion at early megagametogenesis occurring in Indica/Japonica rice crosses. Two major loci, dominant and complementary \%esa\|1.% and \%esa\|2\%, located on chromosomes 6 and 1. respectively, were detected. Genetic analysis indicated that embryo sac fertility is mainly regulated by the gametophytic genotype at these two loci.

关键词： embryo sac abortion gametophytic sterility genetic mapping Oryza sativa L. plant reproduction.