Abstract: Transcriptional regulation of defense gene expression is a crucial part of the plant defense responses. Transcription factors play important roles in the transcriptional regulation of gene expression. Here, we review the structure features and functional characterization of the ERF transcription factors, and based on our current research, discuss the regulatory roles of transcription factors in plant defense responses.

Key words： plant defense responses; transcriptional regulation; GCC-box; ERF transcription factors

Effect of oxalic acid on spore germination and mycelial growth of the mycoparasite Coniothyrium minitans WEI Shan-jun， LI Guo-qing， JIANG Dao-hong， WANG Dao-ben
(Department of Plant Protection, Huazhong Agricultural University, Wuhan 430070， China)

Abstract: Oxalic acid (OA) is a phytotoxin produced by pathogenic fungi including Sclerotinia sclerotiorum. Effect of oxalic acid on spore germination and mycelial growth of C. minitans, the mycoparasite of S. sclerotiorum, was studied in media. The results indicated that OA could not stimulate the spore germination of C. minitans. On unbuffered and buffered media (water agar), the lowest OA concentration for inhibition of C. minitans germination was 150 and 700 μg/mL, respectively. On potato dextrose agar (PDA) amended with OA at 100-2 000 μg/mL, C. minitans could grow，and OA at 300-500 μg/mL in PDA could significantly stimulate the mycelial growth of C. minitans. On an unbuffered synthetic medium amended with OA ranging from 100 to 2 000 μg/mL as the carbon source, C. minitans could grow. The optimum OA concentration was 500 μg/mL and the maximum OA concentration was 2 500 μg/mL. On the buffered media, C. minitans grew at the OA concentration ranging from 100 to 4 000 μg/mL with the optimum OA concentration between 1 500 and 2 500 μg/mL. On opaque media containing calcium oxalate, a clear zone under each colony of C. minitans in each plate was observed. These results suggest that C. minitans could tolerate OA both for its spore germination and for its mycelial growth and C. minitans may degrade oxalic acid.

Key words： Coniothyrium minitans; Sclerotinia sclerotiorum; oxalic acid; toxicity

PCR Assays for Rapid and Sensitive Identification of Three Major Root-Knot Nematodes,Meloidogyne incognita, M. javanica and M. arenaria（English）
MENG Qing-peng,LONG Hai,XU Jian-hua*(Key Laboratory of Monitoring and Management of Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China)

Abstract: To develop a rapid and sensitive method for the detection and identification of Meloidogyne incognita, M. javanica and M.arenaria, four and three random amplified polymorphic DNA (RAPD) fragments specific for M. incognita and M. javanica, respectively, were identified. Based on the sequences of these RAPD markers, various sequence characterized amp lified region (SCAR) primers were designed and tested for their amplification specificity and efficiency against populations of M. incognita, M. javanica, M. arenaria, M. hapla and M. enterolobii. This resulted in three pairs of SCAR primers that were used in combination to reliably and sensitively identify M. incognita, M. javanica and M. arenaria. The SCAR markers can be readily amplified from one third of a single second-stage juvenile, male or female, thus demonstrating that the SCAR-based PCR assays have practical value for routine identification of M. incognita, M. javanica and M. arenaria in soil and
root samples.

Key words: root-knot nematodes; identification; RAPD; SCAR

Mycoparasitism of Gliocladium roseum 67-1 on Sclerotinia sclerotiorum
ZHANG Yong-hua, GAO Hui-lan， MA Gui-zhen， LI Shi-dong （Biological Control Institute, CAAS, Beijing 100081, China）

Abstract: G. roseum 67-1, a strain with high pathogenicity to sclerotia of S. scler
otiorum, was isolated from pea rhizosphere soil collected from Ledong, Hainan
Province. One hundred percent of sclerotia were parasitized 7 d after they were
inoculated with G. roseum 67-1 on PDA plates. Spores of this isolate succeeded in parasitizing sclerotia within 24 h after inoculation. The inhibition band was observed during the dual culture on PDA plates. Microscopic observation of sectioned sclerotia showed that sclerotial tissue collapsed by the parasitism of G. roseum 67-1. Change of protein composition was found in the infected sclerotial tissue. Our results show that this isolate, with ability to grow under wide temperature range and to produce mass spores, is of great potential to control soybean stem rot caused by S. sclerotiorum.

Key words： Gliocladium roseum； Sclerotinia sclerotiorum； parasitism

Isolation and identification of Tobacco mosaic virus infecting Syringa oblate HUANG Jin-guang1, DENG Cong-liang1, FAN Zai-feng1, TIAN Guo-zhong2, LI Huai-fang1*(1Department of Plant Pathology, China Agricultural University, Beijing 100094, China； 2Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China）

Abstract: Rod-shaped virus particles about 300 nm×18 nm were isolated from Syringa oblate expressing systemic mosaic in leaves. The double-stranded RNA pattern revealed one single band of about 6.4 kbp. The virus contained coat protein of approximately 17.6 kDa. According to these results, the virus isolate was identified
as a member of Tobamovirus. A pair of primers were designed based on Toba
movirus RNA RdRp gene, and a fragment of about 1 000 bp（GenBank AY566703）was
amplified by RT-PCR. The PCR product was cloned and sequenced. The sequence sh
ared 99.90% homology with TMV-B strain (GenBank Accession No. AJ011933.1). Anot
her pair of primers was designed based on TMV RNA CP gene. A fragment of about
800 bp（GenBank AY566702）was amplified. The recombinant plasmid was obtained and sequenced. The sequence shared 99% homology with TMV-B strain (GenBank Accessi
on No. AJ011933.1). CP gene sequence and amino acids shared 99.37%, 100% homology with TMV-B strain respectively. On the basis of above results, the virus isolated from S. oblate in Beijing is Tobacco mosaic virus (TMV).

Key words： Syringa oblate; Tobacco mosaic virus (TMV); identification; sequencing

Effects of HMC-toxin on the structure and function of male-sterile cytoplasm c
orn mitochondria WANG Li-an1, HAO Li-mei1, MA Chun-hong2, Chen Xia2 (1College of Life Sciences, Hebei Normal University, Shijiazhuang 050016, China; 2Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050051, China)

Abstract: Under the treatment with a toxin preparation from Bipolaris (Helminthosporium)maydis Race C (HMC-toxin), the inner membrane and cristae of mitochondria from Charrua male-sterile cytoplasm corn (C mitochondria) collapsed and disappeared. The respiratory control ratio (RCR) declined 20% or more in the presence of HMC-toxin. However, the effects of this toxin on mitochondria from the normal cytoplasm counterparts were not apparent. Under the treatment with HMC-toxin only some mitochondria was damaged. In the presence of HMC-toxin RCR declined only
5% or less and the P/O ratio just changed a little. The results indicate that
the HMC-toxin preparation specially affects C mitochondria.

Key words： toxin from Bipolaris （Helminthosporium） maydis race C (HMC-toxin); mitochondria; inner membrane; respiratory control ratio(RCR); P/O ratio

Induced resistance of tobacco to Phytophthora nicotianae by synthetic oligos
accharides ZHU Zhen-yuan1,3, ZHANG Yong-min2, XU Tong1（1 Department of Plant Protection, Zhejiang University, Hangzhou 310029, China; 2 Ecole Normale Supérieure, Département de Chimie, Associé au CNRS, 24, Rue Lhomond, 75231 Paris Cedex 05, France; 3 Laboratory of Fungus Resources, Guizhou University, Guiyang 550025, China）

Abstract: The synthetic oligosaccharides induced tobacco resistance against P. nicotianae and did not inhibit the mycelial growth of the pathogen in vitro. The induced resistance of tobacco plants treated with Lewisx quinquesaccharide or heptasaccharide was related to concentrations used in the range 0-10 μg/mL, treated plants showed the maxium induction efficiency (97.9 %) at 10 μg/mL. The activities of three defense enzymes, polyphenoloxidase, peroxidase and phenylalanine ammoniayase in tobacco plants treated with Lewisx heptasaccharide at 10 μg/mL increased by 70.7%, 150.0% and 142.8%, respectively. The mechanism of the induced resistance is discussed.

Key words： oligosaccharides; Tobacco black shank; induced resistance; defense enzymes

Specificity and partial characterization of an elicitor (CSB I) from Magnaporthe grisea LI Yun-feng， WANG Zhen-zhong*， JIA Xian-lu（College of Resource and Environmental Sciences, South China Agricultural University， Guangzhou 510642, China）

Abstract: With four near-isogenic resistant lines (NIL) of rice, specificity and partial characterization of a glycoprotein elicitor CSB I from Magnaporthe grisea were studied. The results showed that, after treatment with CSB I, the phytoalexin production in highly incompatible rice C101LAC was higher than that in compatible rice CO39. The elicitor CSB I could also induce hypersensitive reaction in leaves of completely and highly incompatible rice, but not in the other two NIL rice (moderate incompatible rice and compatible rice). These results suggested that CSB I was cultivar-specific. Digestion with trypsin and boiling at 100℃ for 10 min did not abolish the elicitor activity, whereas the complete loss of elicitor activity was observed after periodate treatment, which suggested that the carbohydrate
moiety contained the active site of the elicitor. The elicitor CSB I could maintain its activity of inducing POD and PAL activity in rice leaves after acid and weak alkali treatment. The elicitor was sensitive to strong alkali. Elicitor CSB I could induce POD and PAL activity in rice leaves at different doses ranging from 0.70 nmol/L to 7.00 nmol/L but not at 0.07 nmol/L, indicating that the minimal efficient dosage of CSB I was between 0.07-0.70 nmol/L.

Key words： Magnaporthe grisea; rice; elicitor; specificity; active site

Genetic diversity analysis of varieties of Glycine max (L.) Merr resistant to Soybean mosaic virus by SSR fingerprints MI Shi-jun1,2, QIU Li-jun1, CHANG Ru-zhen1, HAO Zai-bin2, GUAN Rong-xia1(1Key Laboratory of Crop Germplasm & Biotechnology, The Ministry of Agriculture, Institute of Crop Germplasm Resources, Chinese Academy of Agricultural Sciences, Beijing 100081, China; 2College of Biology Science, Northeast Agricultural University, Harbin 150030, China)

Abstract: The genetic diversity of 113 soybean varieties with high resistance to SMV was evaluated using 61 SSR primers. A total of 387 allelic variants were obtained in the varieties with average 6.34 alleles per SSR locus. Nei-Li genetic similarity coefficients were calculated using the software of NTSYS-pc2.10t and a dendrogram was constructed by the unweighted pair group method of arithmetic average (UPGMA). Mean similarity coefficient among the varieties was up to 0.295, which indicated that genetic difference among them was significant. Based on the genetic similarity coefficient matrix, the varieties were divided into seven groups. The varieties with the same geographical origin and the approximate pedigree were clustered together. The varieties whose genetic similarity coefficients were small and that were clustered in the different group probably carried the different resistant genes.

Key words： soybean (G. max); Soybean mosaic virus;SSR; genetic diversity

Simulation study on cultivar deployment against Wheat stripe rust caused by
Puccinia striiformis West. in China ZENG Shi-mai (China Agricultural University, Beijing 100094, China)

Abstract: The effect of cultivar deployment for resistance against stripe rust in China was studied with the model PANCRIN. Simulation results showed that the break-down of resistance might be consi-derably delayed with a proper cultivar deployment. However, this delay may also be affected by several factors, such as the area of different resistant cultivars, pathogen infection rate and fluctuation of wheat-planting area in the regions where the pathogen oversummers. Development of cultivar deployment strategy should be based on consideration of the variation in wheat maturity in the regions where the pathogen oversummers, namely, the culti
var deployment should consider the wheat maturity as detailed as on a field
scale. The wheat-planting area of each resistant cultivar should be optimized, and
the number of resistant cultivars should be increased. Under the conditions the
model used, the maximum percentage of planting area for each resistant cultivar
is suggested to be ＜15%, and the number of resistant cultivars should be ≥6.
In order to minimize the inoculum potential of disease pandemics, the areas of the universally susceptible cultivars is suggested to be limited to less than 10%.
The figures suggested above are for reference only and can not yet be used as
control index because the system concerned is very complicated. The strategy for
deployment should be further developed based on the fully understanding of the p
athogen oversummering process and patterns. Under the current production situati
on, increasing and using as many resistant cultivars as possible is still sugges
ted to manage the disease. As long as not many same resistant cultivars are used in both upper and lower reaches regions of the pandemic system, the lifetime of
resistance in these cultivars could be prolonged.

Key words： Wheat stripe rust; cultivar-deployment； simulation

The role of regulatory gene gacA in the suppression of soil-borne diseases
by Pseudomonas fluorescens 2P24 YAN Xiao-xue1,2, ZHANG Li-qun1*, YANG Zhi-wei2, TANG Wen-hua1(1China Agricultural University, Beijing 100094, China; 2North-West
Science and Technology University of Agriculture and Forestry, Yangling, Shaanxi 712100, China)

Abstract: Pseudomonas fluorescens 2P24, a biocontrol agent isolated from suppressive soil of wheat take-all disease, protects plants against soil-borne diseases. This strain produces several antibiotic secondary metabolites, such as 2,4-diacetylphloroglucinol (2,4-DAPG), hydrogen cyanide (HCN), siderophore and proteases. A mutant strain PM3390 obtained by Tn5 mutagenesis showed pleiotropic changes on the production of secondary metabolites including overproduction of siderophore and nonproduction of 2,4-DAPG, HCN and protease. PM3390 was also unable to form biofilm. These phenotypes were complemented by a 1.2 kb DNA fragment obtained from the genomic DNA library of P. fluorescens 2P24. Sequence analysis revealed a 642 bp open reading frame (ORF) which was highly homologous to the response regulator gene gacA. In greenhouse, the gacA-negative mutant showed decreased ability to suppress soil-borne diseases compared with that of wild type 2P24. The results revealed that gacA gene, a global regulator in the P. fluorescens 2P24, played an important role in biocontrol of soil-borne plant diseases.

Key words： Pseudomonas fluorescens; two-component regulatory system; gacA gene; biocontrol

The fungistatic activities of bleeding sap of sponge gourd on Botrytis cinerea
LIU Wei， ZHU Xiao-ping， GAO Shu-guo， ZHOU Li-yan， SHI Feng-yu， HOU Dong-jun
(Dept. of Agronomy, Hebei Normal University of Science & Technology, Chang Li 066600, China)

Abstract: The inhibition activity of bleeding sap of sponge gourd on Botrytis cinerea
was conducted in vitro and in vivo. The bleeding sap expressed strong inhibition activities on infection, growth, sporulation of Botrytis cinerea. Fungistatic activity of the bleeding was stable when temperature was less than 80℃, and could last for more than one year when stored at room temperature.

Key words： bleeding sap of sponge gourd； Botrytis cinerea； fungistatic activities； stabilities

Biological characteristics of Chinese strain of Venturia inaequalis HU Xiao-ping， YANG Jia-rong， MEI Na， TIAN Xue-liang， YANG Zhi-wei(College of Plant Protection, Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi 712100, China)

Abstract: Biological characteristics of V. inaequalis (Cooke) Wint. had been prelimina rily studied. Optimal mediums for V. inaequalis growth were apple leaf juiceagar, apple fruit juice agar, malt extract agar, PSA, PDA, V8 medium and po
tatomaltose agar medium. For mycelial growth of V. inaequalis, optimal range of
pH was 5.0-6.5, and temperature was 15-20℃. Among the tested carbon and nitr
ogen resources, sucrose, glucose, fructose, maltose, yeast extract, sodium
nitrate and beef extract were beneficial for mycelial growth and sporulation. Ammon
ium sulfate suppressed the sporulation. Ammonium oxalate suppressed growth and
sporulation of the pathogen. Light intensity (600 lx) with fluorescent light for 12h photoperiod had significant effect on mycelial growth and sporulation on PSA
medium at 20℃. The sporulation was 13 times as that under dark. For conidial
germination in water drop, optimal range of temperature was 20-25℃, and pH was
5.0-6.5.

Key words：apple； Venturia inaequalis； cultural medium； biological characteristics

Etiology of tomato basal stem rot and its control in protected culture
XU Zuo-ting， LI Lin， LI Chang-song， QI Jun-shan， JIA Xi (Plant Protection Institute， Shandong Academy of Agricultural Sciences， Jinan 250100， China)