Abstracts of Vol. 28 No. 4

Original Article

Three-Dimensional Modeling of Plant 4-Hydroxyphenylpyruvate Dioxygenase, a Molecular Target of Triketone-Type Herbicides

Hitoshi KAKIDANI⁺ and Kenji HIRAI

Sagami Chemical Research Center, 2743-1 Hayakawa, Ayase, Kanagawa 252-1193, Japan
⁺Tosoh Corporation, 2743-1 Hayakawa, Ayase, Kanagawa 252-1123, Japan

(Received May 23, 2003; Accepted July 22, 2003)

J. Pesticide Sci. 28, 409-415(2003)

Homology modeling of plant 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) was carried out using structural information on the Pseudomonas fluorescens enzyme as a template. A three-dimensional structural model of the barley enzyme was investigated in detail to compare its catalytic pocket with that of the Pseudomonas enzyme. Striking conservation of the catalytic pocket provided a rational basis for designing potent 4-HPPD inhibitors by the in silico docking of compounds and model/template enzymes.

Key words: 4-HPPD, enzyme inhibitor, homology modeling, SWISS-MODEL.

Induction of Resistance against Rice Blast Disease by a Novel Class of Plant Activator, Pyrazolecarboxylic Acid Derivatives

Masanori NISHIOKA, Hideo NAKASHITA,^*,+, Hiroyuki SUZUKI, Shigeaki AKIYAMA,^#
Shigeo YOSHIDA⁺⁺ and Isamu YAMAGUCHI^+,#2

Biological Research Laboratories, Nissan Chemical Industries, Ltd., 1470 Shiraoka, Minamisaitama, Saitama 349-0294, Japan
^*Microbial Toxicology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
⁺Plant Functions Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
^#Chemical Research Laboratories, Nissan Chemical Industries, Ltd., 722 Tsuboi, Funabashi, Chiba 274-8507, Japan

(Received May, 19, 2003 ; Accepted July 23, 2003)

J. Pesticide Sci. 28, 416-421 (2003)

Synthesis and characterization of anti-rice blast activity of pyrazole derivatives was described. Structure-activity relationship study indicated that a carboxyl group at 5-position of 1-methyl-1H-pyrazole played an important role in the activity and that a halogen atom such as a chlorine or bromine at 3-position enhanced the activity. Among the derivatives, 3-chloro-1-methyl-1H-pyrazole-5-carboxylic acid (CMPA) exhibited the highest anti-rice blast activity with the ED₈₀ (80% effective dose, the concentration needed for 80% inhibition of disease development) of 0.05 mg/pot. CMPA did not have any significant effects on the hyphal growth, spore germination, and appressorium formation of Pyricularia oryzae, suggesting that CMPA induces systemic acquired resistance in rice plants.

Key words: carice blast, Pyricularia oryzae, systemic acquired resistance, pyrazolecarboxylic acid.

Determination of Organophosphorus Pesticide Residues in Onion and Welsh Onion by Gas Chromatography with Pulsed Flame Photometric Detector

Eiji UENO, Harumi OSHIMA, Isao SAITO, Hiroshi MATSUMOTO and Hiroyuki NAKAZAWA⁺

Aichi Prefectural Institute of Public Health, Tsuji-machi, Kita-ku, Nagoya, Aichi 462-8576, Japan
⁺Department of Analytical Chemistry, Faculty of Pharmaceutical Science, Hoshi University, Ebara, Shinagawa-ku, Tokyo 142-8501, Japan

(Received May 20, 2003 ; Accepted July 25, 2003)

J. Pesticide Sci. 28, 422-428 (2003)

A rapid gas chromatographic method for determining organophosphorus pesticide residues in allium such as onion and welsh onion containing high levels of sulfur-matrices was studied. A sample was extracted with acetonitrile and the acetonitrile layer separated by salting-out. The extract was cleaned up with gel permeation chromatography, and then with a tandem silica-gel/PSA mini-column. The test solution was subjected to gas chromatography with a pulsed flame photometric detector. Organophosphorus pesticide residues in such sulfur-rich matrices were determined without any serious interfering peaks on the chromatograms by diluting the extracts 8-fold (0.25 g/ml of sample). No additional pretreatment to deactivate enzymes which caused interference was necessary. The rate of recovery of 36 organophosphorus pesticides from fortified onion and welsh onion ranged from 61 to 105% with the RSD usually ＜10% for five experiments. The detection limits of these pesticides were good (0.002-0.01 mg/kg) for monitoring organophosphorus pesticide residues in agricultural products including allium, except for degradable trichlorfon. The method was applied to onion and welsh onion to demonstrate its use in routine analysis.

Key words: organophosphorus pesticide residues, onion, welsh onion, sulfur-matrices, gas chromatography, pulsed flame photometric detector

Note

Estimation of Out-Crossing Rate in Monochoria korsakowii Using the Herbicide Resistance Trait as a Marker

Guang-Xi WANG,^* Hiroaki WATANABE,⁺ Akira UCHINO,⁺ Wei LI^# and Kazuyuki ITOH⁺

Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
+National Agricultural Research Center for Tohoku Region, Omagari, Akita 014-0102, Japan
#Wuhan Institute of Botany, Chinese Academy of Sciences, Hubei 430074, People's Republic of China

(Received April 17, 2003 ; Accepted May 13, 2003)

J. Pesticide Sci. 28, 429-430 (2003)

In order to discuss the rate of dispersion of the resistance gene of Monochoria korsakowii, we quantitatively estimated the out-crossing rates using the herbicide resistance trait as a marker on experimental populations. Two insect species, Apis mellifera and Xylocopa circumvolans, were observed on the flowers and the estimated out-crossing rates ranged from 10.4 to 67.8% with an average of 36.2%. The finding indicates that the trait can be transmitted via pollen by bees and expressed in hybrid offspring and further implies that the subsequent spread of resistance can occur through pollen migration. Thus, the evolution of resis-tance will be rapid.

Key words: acaricidal acitivity, Tetranychus urticae, N-(1, 3, 4-thiadiazol-2-yl)pyrazole-5-carboxamides, N-(1, 3, 4-thiadiazol-2-yl)thiazole-5-carboxamides.

PART II (IN JAPANESE)

Original Article

Effects of Ethephon Application on Plant Height and Leaf Color in Summer-to-Autumn-Flowering Chrysanthemum

Hiroyuki SUGIURA and Masayoshi FUJITA⁺

The United Graduate School of Agricultural Science, Gifu University, Yanagito, Gifu 501-1193, Japan
+ Faculty of Agriculture, Shinshu University, Minamiminowa, Kamiina-gun, Nagano 399-4598, Japan

The effects of ethephon spraying on the growth development, flower bud stage and leaf color were studied in a summer-to-autumn-flowering chrysanthemum (Dendranthema grandiflorum (Ramat.) Kitamura) under open field conditions. The growth of all cultivars was slow until the last ethephon spraying stage, but that from the involucre formation stage to the floret formation stage was fast and growth before flowering was slow again. Leaf segments grew after rosette formation at high positions under a schedule of three 200 mg/l ethephon sprayings with 1000 mg/l for strong inhibition of flower bud differentiation. The plant height overtook that achieved with three 200 mg/l ethephon sprayings in ‘Seiun’ and ‘Summer-yellow’ cultivars. First growth using ethephon sprays with pinching was slower than that without pinching. Leaf color of flowers treated with ethephon sprays and pinching was more inhibited than that without pinching in all cultivars. Our results showed that, ethephon spraying inhibited early flower bud differentiation, growth of stems and change of leaf color to dark green, however, the stem length was longer than controls because the growth of stems is fast in summer-to-autumn-flowering chrysanthemum.

Key words: chrysanthemum, ethephon, flower bud differentiation, leaf color, plant height.

Commentaries

Current Topics and Problems Concerning Fungicides against Seed-Borne Pathogens in Vegetable and Ornamental Crops
Hajimu KOMADA and Koichi ASAGA

Key words: topics and problems, fungicides, seed-borne pathogens.

Brassinosteroid Signaling
Takeshi NAKANO, Shigeo YOSHIDA and Tadao ASAMI

Key words: brassinosteroid, Arabidopsis, photomorphogenesis, chloroplast development, Brz.

Newly Registered Pesticides and Cancelled Pesticides in Calendar Year of 2002
Yasuo ISHII

Key words: registered pesticides, cancelled pesticides.

Protein Crystallography─Crystallization─
Toshiji TADA

Key words: protein crystallography, crystallization, sparse matrix, fructose-1, 6-/sedoheptulose-1, 7-bisphosphatase, ascorbate peroxidase, glyceraldehyde-3-phosphate dehydrogenase.

A New Method for Measuring Plant Cuticular Permeability without Using Radioisotopes
Yuichi MAEKAWA

Key words: floating method, plant cuticular permeability, monuron.

Minireviews: Biotechnologies in Plant-Protection

　Functions of ABC Transporters in Phytopathogenic Fungi
Ryoji NAKAUNE

Key words: ABC transporter, multidrug resistance, pathogenicity, phytopahogenic fungi.

Studies on the Expression of Cytochrome P450s by cDNA Array Tequnique: for the Search of New Insecticide Targets and Elucidation of Resistance Mechanisms
Shinji KASAI and Takashi TOMITA

Key words: cDNA array, cytochrome P450 monooxygenase, ecdysone, Cyp312a1, insecticide resistance, target site.

Resistance to ALS-Inhibiting Herbicides in WeedsAkira UCHINO479
Akira UCHINO

Key words: acetolactate synthase, ALS inhibitor, herbicide resistance, sulfonylurea, paddy weed.

Histidine Kinase Signal Transduction and Fungicide-Resistance in Fungi
Makoto FUJIMURA

Key words: histidine kinase, dicarboximide, phenylpyrrole, resistance.

His-Asp Phosphorelay in Plant Hormone Responses
Takeshi MIZUNO

Key words: plant hormones His-Asp phosphorelay, signal transduction.