First report of an endophyte (Diaporthe phaseolorum var. sojae) from Kandelia candel

Mangrove endophytic fungus 1893 was isolated from Kandelia candel from an estuarine mangrove on the South China Sea Coast. Two new lactones 1893A and 1893B, together with other known compounds, have been isolated from its fermentation broth. To classify the endophyte correctly for further industrial application, a combination of morphological and molecular techniques was used to approach its identity. The endophyte was compared with similar species having trichogynes or trichogyne-like hyphae which apparently fused with antheridium-like hyphae, and perithecia initials developing from an ascogonial coil surrounded by enveloping hyphae in early developmental stages on pure culture. Further morphological characteristics on host and non-host were used for comparison with similar species when the endophyte was cultivated on leaves of Kandelia candel and Mangifera indica, respectively, which resulted in classifying the endophyte as a Phomopsis species. The ITS sequence of rDNA was used to infer its phylogenetic relationships with Phomopsis species that resembled the strain in morphology or ecology. Finally, the endophyte was identified as Diaporthe phaseolorum var. sojae based on morphological and molecular evidence. Our study is a first report of Diaporthe phaseolorum var. sojae isolated from mangrove Kandelia candel. Foundation item: The search was supported partly by the Guangzhou Natural Science Foundation (Grant No. 2007Z3-EO581), the Guangdong Provincial Natural Science Foundation (Grant No. 2007A0200300001-7), the Chinese High-Tech 863 Project (Grant No. 2006AA09Z422), and the National Natural Science Foundation of China (Grant No. 20572136). The first two authors have the same contribution.     

Pistil development in 2 types of flowers of Xanthoceras sorbifolia

In order to investigate flower development and female abortion during sex differentiation of Xanthoceras sorbifolia, anatomical observations and comparative study on differential proteins were carried out in different developmental stages of two types of flowers of this species. It was found that the selective abortion happened in male flower before the formation of megasporocyte. Special proteins related to the female abortion were found through 2-dimensional electrophoretic analysis. Protein A1 (14.2 kD) only existed in florescence of male flower, while B1 (13.7 kD) and B2 (18.2 kD) disappeared in that stage of male flower. They were all considered to be relative to pistil abortion of Xanthoceras sorbifolia. [Supported by the National Natural Science Foundation of China (Grant No.30070613) and Graduate Cultivation Foundation of Beijing Forestry University (Grant No.02jj001)]     

Cloning and RNAi construction of a LEAFY homologous gene from Populus tomentosa and preliminary study in tobacco

PtLFY, a LEAFY (LFY) gene, was cloned from Populus tomentosa (LM50) by PCR. Sequencing analysis indicated that PtLFY was 2 629 bp long, composed of three exons and two introns and encoded 378 amino acids. The splice donor sites and the splice acceptor sites were in identical positions to the LFY and its homologues. The amino acid sequence inferred was 68%-99% homologous to those of LFY and its homologues by blast analysis in GenBank. The Southern blot analysis indicated that there was a single copy of the PtLFY gene in genomic DNA of male and female P. tomentosa (LM50 and 5082). The pBI121-Ptalfy (reverse)-intron-Ptlfy-GUS-nos was constructed using RNA interference (RNAi) technique and verified by PCR and digestion identification and transformed into tobacco. Some transgenic tobacco plants were obtained by PCR and PCR-Southern identification. The growth was generally repressed in transgenic tobacco plants compared with wild-type ones and some phenotypic differences were observed. [Supported by the National Natural Science Foundation of China (Grant No. 30371175) and Postdoctoral Foundation of China (Grant No. 2002032041)]     

红树林内生真菌1403的形态与分子鉴定(英文)

红树林内生真菌1403是从中国南海分离的一株镰刀菌,在液体发酵条件下能够产生灰黄霉素和葸醌类的抗生素。基于1403在形态学方面具有以下特征:产小型分生孢子的分生孢子梗较长,小型分生孢子呈椭圆形,大型分生孢子线形或略微弯曲,本文将它与有类似形态特征的镰刀菌进行了比较,发现1403与植物病原菌Fusarium verticillioides(有性态为Gibberella moniliforme)表面上很相似,气生菌丝均可产生大量假头状或链状的小型分生孢子,但深入的研究却发现1403与F.verticillioides具有不同的性状,如产生的多生分生孢子梗有时与单生分生孢子梗长度相当,产生环状菌丝,以及菌丝发生融合等现象,进一步以最大简约法和贝叶斯分析法将1403与其它相似镰刀菌进行系统发育比较,综合18S、28S、ITS三水平上的分析结果可以将1403归于镰刀菌亚组Gibberella fujikuroi,并最终在EF—1α水平上将其定为Fusarium proliferatum.     

Analysis of synonymous codon usage in chloroplast genome of Populus alba

The pattern of codon usage in the chloroplast genome of Populus alba was investigated. Correspondence analysis （a commonly used multivariate statistical approach） and method of effective number of codons （ENc）-plot were conducted to analyze synonymous codon usage. The results of correspondence analysis showed that the distribution of genes on the major axis was significantly correlated with the frequency of use of G＋C in synonymously variable third position of sense codon （GC3S）, （r=0.349）, and the positions of genes on the axis 2 and axis 3 were significantly correlated with CAI （r=-0.348, p〈0.01 and r=0.602, p〈0.01）. The ENc for most genes was similar to that for the expected ENc based on the GC3s, but several genes with low ENc values were lying below the expected curve. All of these data indicated that codon usage was dominated by a mutational bias in chloroplast gcnome ofP. alba. The selection in nature for translational efficiency only played a minor role in shaping codon usage in the chloroplast genome ofP alba.     

Bio-control trials of Chaetomium spirale ND35 against apple canker

A new endophytic antagonistic fungus, Chaetomium spirale ND35 from Populus tomentosa, was reported. The bio-control trials of C. spirale ND35 against the Valsa Canker of apple were preliminarily investigated. The results of dual culture on PDA plate showed that C. spirale ND35 was capable of strong antagonism against Valsa ceratosperma, and for inhibiting the mycelial growth of V. ceratosperma,.the crude extract of liquid culture of corn steep powder broth was more effective than that one of malt extract broth (MEB). The results of bio-control in greenhouse and field indicated that the disease incidence of apple tree treated with C. spirale ND35 was lower significantly than that treated by other methods. The re-isolation experiment suggested that C. spirale ND35 could colonize in stems and branches of apple trees successfully, and the ND35 colonization rate of the treatment with solid wheat bran culture was higher than that of corn steep powder broth, but the field experiment result the control effect of liquid culture of C. spirale ND35 was better than that of solid culture.     

Expression of a carrot 36 kD antifreeze protein gene improves cold stress tolerance in transgenic tobacco

Antifreeze proteins （AFPs） enable organisms to survive under cold conditions, and have great potential in improving cold tolerance of cold-sensitive plants, In order to determine whether expression of the carrot 36 kD antifreeze protein gene confers improved cold-resistant properties to plant tissues, we tried to obtain transgenic tobacco plants which expressed the antifreeze protein. Cold, salt, and drought induced promoter Prd29A was cloned using PCR from Arabidopsis. Two plant expression vectors based on pBI121 were constructed with CaMV35S：AFP and Prd29A：AFP. Tobacco plantlets were transformed by Agrobacterium-medicated transformation. PCR and Southern blotting demonstrated that the carrot 36 kD afp gene was successfully integrated into the genomes of transformed plantlets. The expression of the afp gene in transgenic plants led to improved tolerance to cold stress. However, the use of the strong constitutive 35S cauliflower mosaic virus （CaMV） promoter to drive expression of afp also resulted in growth retardation under normal growing conditions. In contrast, the expression of afp driven by the stress-inducible Prd29A promoter from Arabidopsis gave rise to minimal effects on plant growth while providing an increased tolerance to cold stress condition （2℃）. The results demonstrated the prospect of using Prd29A-AFP transgenic plants in cold-stressed conditions that will in turn benefit agriculture.     

Constitutive expression of sense &; antisense <Emphasis Type="Italic">PtAP3</Emphasis>, an <Emphasis Type="Italic">AP3</Emphasis> homologue gene of <Emphasis Type="Italic">Populus tomentosa</Emphasis>, affects growth and flowering time in transgenic tobacco

To analyze the function of PtAP3, an APETALA3 （AP3） homologue gene isolated from Populus tomentosa Carr., the full length sequence （1797 bp） and a fragment （870 bp） of PtAP3 were fused to a CaMV 35S promoter of pBI121 to generate the sense and antisense constructs of PtAP3. These constructs were transformed into tobacco by Agrobacterium infection of leaf disks and selection on kanamycin medium. Some sense and antisense transgenic tobacco plants were obtained by PCR and Southern blot analysis. Great phenotypic differences in transgenic tobacco plants were observed. Almost all of sense PtAP3 to transgenic tobaccos showed a higher growth rate than those of antisense transformants and a few developed pregnancy earlier than wild type seedlings and antisense transformants under the same conditions.     

Cloning and analysis of telomere-associated sequences of <Emphasis Type="Italic">Ginkgo biloba</Emphasis> L.

Total genomic DNA was extracted from leaves of Ginkgo biloba L. by the method of hot CTAB. After determining quantification of DNA sample by microclorimetric spectrophotography, Arabidopsis-type telomere primer and Sau3A I cassette primer were used to isolate telomere-associated sequences from G. biloba L. by the method of cassette-ligation-mediated polymerase chain reaction (PCR). Using this method, two telomere-associated sequences, TAS1 and TAS2, were isolated. The authors preformed Southern hybridization ofEcoR I-treated G. biloba genomic DNA with each clone. The hybridization pattern showed that the clones obtained were derived from G. biloba genomic DNA. There are the Arabidopsis-type TTTAGG tandem repeats in telomeres of G.biloba.     

Micropropagation and callus culture of <Emphasis Type="Italic">Saussurea laniceps</Emphasis>, an alpine medicinal plant

Cottonhead windhairdaisy (Saussurea laniceps Hand.-Mazz.) is one of the most famous and important medicinal herbs in China. Illegal collection from wild populations is increasingly threatening the present environment of S. laniceps. Establishment of an efficient method for micropropagation is the best way to change its endangered situation. When mature seeds of S. laniceps were cultured on hormone-free MS medium, plantlets were formed from germinated seeds in 7–10 d. Then 0.5 cm × 0.5 cm leaf explants were transplanted to MS medium supplemented with 1-naphthalene-acetic acid (NAA)/2,4-D and benzyladenine (BA)/KT and callus was achieved 10 d after transfer. Shoot bud regeneration occurred from callus cultured on MS medium supplemented with different growth regulators 20 d after culturing. The regeneration percentages varied with the different components of plant growth regulators. The percent regeneration from callus pretreated at low temperature of 5°C increased significantly compared with those incubated at 23/20°C directly. Optimal regeneration was observed with explants on media supplemented with 1.5 mg&#8226;L^–1 BA plus 0.2 mg&#8226;L^-1 NAA. In the presence of 0.2 mg&#8226;L^–1 NAA in half-strength MS, 78% of the shoots formed roots. Plantlets from explants showed 63% survival after acclimatization.     

Cloning and sequence analysis of a glucose-6-phosphate dehydrogenase gene <Emphasis Type="Italic">PsG6PDH</Emphasis> from freezing-tolerant <Emphasis Type="Italic">Populus suaveolens</Emphasis>

A 1207 bp cDNA fragment (PsG6PDH) was amplified by RT-PCR from cold-induced total RNA of the freezing-tolerant P. Suaveolens, using primers based on the highly conserved region of published plant glucose-6-phosphate dehydrogenase (G6PDH) genes. The sequence analysis showed that PsG6PDH coding region had 1 101 bp and encoded 367 predicted amino acid residues. Moreover, the nucleotide sequence of PsG6PDH showed 83%, 82%, 79%, 79% and 78% identity, and the derived amino acid sequence shared 44.2%, 44.7%, 42.0%, 40.5% and 43.9% identity with those of the Solanum tuberosum, Nicotiana tabacum, Triticum aestivum, Oryza sativa and Arabidopsis thaliana, respectively. The results show that PsG6PDH is a new member of G6PDH gene family and belongs to the cytosolic G6PDH gene. This is the first report on cloning of the G6PDH gene from woody plants.     

Responses of fractal dimensions ofPicea koraiensis seedlings to different light environments

The changes of fractal dimension ofPicea koraiensis seedlings under different light intensities in natural secondary forests was studied. The results showed that with the change of light environment, crown characters ofPicea koraiensis seedlings exhibited a greater plastic in lateral number, lateral increment, lateral dry weight, and specific leaf area. The range of calculated fractal dimensions of seedling crowns was confined between 2.5728 and 2.1036, but maximum of fractal dimension achieved in term moderate shading and in extreme low light conditions fractal dimension was least. Foundation item: This paper was supported by the National Natural Science Foundation of China (No.39670152) and Chinese Academy of Sciences. Biography: ZHOU Yong-bin (1970-), female, Ph. Doctor, lecture in Shenyang Agricultural University, Shenyang 110161, P.R. China Responsible editor: Song Funan     

High level expression of glucose-6-phosphate dehydrogenase gene <Emphasis Type="Italic">PsG6PDH</Emphasis> from <Emphasis Type="Italic">Populus suaveolens</Emphasis> in <Emphasis Type="Italic">E. coli</Emphasis>

In order to investigate the functions of the gene PsG6PDH and the mechanisms underlying freezing tolerance of Populus suaveolens, the recombinant expression vector pET-G (pET30a-G6PDH), which contained full encoding region of PsG6PDH gene, was established. The recombinant was identified by lawn-PCR and double enzyme digestion and then transformed into expression host XA90 and induced by isopropyl-â-D-thiogalactoside (IPTG) to express 100 kD polypeptide of G6PDH fusion protein. The results showed that the expressed amount of the fusion protein culminated after 1 mmol&#8226;L^–1 IPTG treatment for 4 h and that pET-G product was predominately soluble and not extra-cellular secreting.     

高效液相色谱法测定羟基喜树碱含量方法的研究

The determination method of 10-hydroxycamptothecin inCamptotheca acuminatu fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C₁₈(4.6×250 mm) column with mobile phase of acetonitrile-water (3:7, V:V), flow rate 1 mL·min⁻¹ and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits ofC. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60°C for 50 minutes. Foundation Item: This paper was supported by National Natural Science Foundation of China (No. 30070086). Biography: MA Mei-fang (1976-), female, Graduate Student of Northeast Forest University. Responsible editor: Song Funan     

Relationship between stomatal behavior and characteristics of photosynthesis and transpiration ofAdenophora lobophylla andA. potaninii at different altitudes

The photosynthesis and transpiration characteristics ofAdenophora lobophylla andA. potaninii, as well as stomatal behavior such as stomatal size, stomatal density, stomatal open and stomatal conductivity were measured at different altitudes. The relationship between the photosynthesis and transpiration characteristics and the stomatal behavior was analysed by correlation coefficient and path coefficient analysis with altitude changes. The results showed that the influences of stomatal behavior were not evident on the photosynthesis and transpiration characteristics ofA. Lobophylla, but evident on that ofA. potaninii. This study is supported by the National Natural Science Foundation of China (No. 39391500). Responsible editor: Zhu Hong     

Research progress on production of podophyllotoxin from Sinopodophyllum hexandrum

Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer, testicular cancer, neuroblastoma, hepatoma and other tumors. However, these plants are all near-extinction species due to over-collection and their own biological characteristics. The chemical synthesis of podophyllotoxin is so complicated that its price is unbelievably high. This paper discusses the current status of the biosynthetic pathway of podophyllotoxin and that of the podophyllotoxin production using several biotechnological approaches such as plant organ cultures, plant cell cultures with both flasks and bioreactors, hairy root cultures, bioconversions and metabolic regulations. [Supported by the Natural Science Foundation of Tibet (Grant No. 2002-66)]     

不同损伤形式诱导合作杨挥发物释放差异的研究

Three treatments including mechanical damage, Lymantria dispar attacking and daubing oral secretions of the insects on mechanically damaged cut were conducted on Populus simoniixPopulus pyramibalis c.v. in order to find the genuine reason leading to effective resistance response of tree to insects attacking. The release situation of the induced volatiles of the plant was analyzed by TCT-GC/MS at 24 hours after damages. The results indicated that some of the volatiles such as (Z)-3-hexenyl acetate, decanal, 3-hexenyl isovalerate, nonanal, ocimene, and 2-cyanobutane can be induced by both insects attacking and mechanical damage, while 2,6-dimethyl-1,3,5,7-octatetraene, 2-methyl-6-methylene-1,7-octadien-3-one, caryophyllene,Isovaleronitrile, diethyl-methyl-benzamide, and dicapryl phthalate were only induced by insects attacking. Such difference in volatiles was attributed to that there existed active components in oral sections of the larvae of Lymantria dispar     

Formation, distribution, and nature ofPicea mongolica in China

Picea mongolica is an endemic and endangered species in China. Ecosystem made ofPicea mongolica is a special sandy forest ecosystem in China. It is found at ecotone between forest and steppe, or agricultural district and pas toral area. Based on investigation, this paper discussed the formation and distribution ofPicea mongolica and studied its nature according to ecotone theory. It is clarified thatPicea mongolica belongs toPicea meyeri series. That is to say, it became a local race through long-term adaptation to the local climate, then formed allopatric semi-species, and finally turned into a taxonomical species.Picea mongolica forest is a super zonal climax community developing in ecotone between forest zone and steppe zone. Foundation item: The study was supported by National Natural Science Foundation of China (39670133, 39900019, 30070129). Biography: ZOU Chun-jing (1968-), male, Ph.D, associate researcher fellow in Institute of Applied Ecology, Chinese Academy of Science, Shenyang 110015, P. R. China Responsible editor: Chai Ruihai     

Living characteristics of rare and endangered species —Davidia involucrata

Dovetree (Davidia involucrate), one of the first-class protective plants in China, is a relic species of paleotropical kingdom in Tertiary period, belonging toDavidiaceae with a single genus. In recent years, the increase of regional developing projects has led to a sharp decrease of this ancient and rare plant in naturally distributed habitats and natural population. In this paper, the biological and ecological characteristics of Dovetree were described, and the geographically distributed condition of this species in different geologic periods as well as the major reasons for dynamic changes of its population were systematically analyzed in accordance with field researches and references. The investigations conducted in different years by setting up standard sample plots showed that the population number of Dovetree increased yearly in the areas without human interference but decreased yearly in the areas with human interference. With the increase of population density and human activities decreased as the logarithmic curve:Y=−100.7ln(x)+178.09, and it has turned from a dominant population into an endangered population. Based on the former and present studies on Dovetree, some protection strategies were put foreword for protecting this ancient and rare species. Foundation Item: This research was coordinated by the National Natural Science Foundation of China (No. 39970591) Biography: Wu Gang (1965-), Male, Professor in Key Laboratory of Systems Ecology, Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Responsible editor: Chai Ruihai     

Research on the extension ofTamarix shrubs resulted from development projects in arid area

Tamarix plant is widely distributed in the arid areas of China for its great tolerance of draught, salt and alkali and attracts more attention by its strong capacity in windbreak and sand-fixations. “Tamarix dunes” constitute special desert bio-landscape in arid area. During last several decades,Tamarix shrubs declined and “Tamarix dunes” were also severely destroyed due to the land exploitation and serious deforestation, etc. From the 1980s until now, the extending phenomenon ofTamarix shrubs caused by developmental projects such as building highway, railway was studied in the western dry area of China, including western section of Hexi Corridor of Gansu, railroads and highways around the two greatest basin in Xinjiang and interior regions in Gurbantonggut desert, through on-the-spot survey along the transportation lines and setting up sampling plots along the roads. It was found that large quantities ofTamarix plants grow in the catchment area of low-lying lands that were formed by bulldozer operation during road building period. The extension ofTamarix shrubs caused by engineering was similar to that of the other section of the area to some extent, but went beyond the original distribution. This extension is beneficial to the ecological restoration and re-vegetation of western region of China and plays an important role in control of the sandstorms and improvement of ecological environments. As a result, it is necessary to make a further study on the extending phenomenon ofTamarix shrubs and to seek approach to promote wider extension ofTamarix shrubs in suitable habitats. Foundation Item: This study is supported by key projects of National Natural Science Foundation (39730100), National Foundation (30070640) and part of Project 973(G19990435). Biography: Huang Pei-You (1936-), Male, Professor in College of Life Science and Technology, Xinjiang University, Urumqi, 830046 Responsible editor: Chai Ruihai