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121.
122.
cDNA microarray analysis of gene expression in rice plants treated with probenazole,a chemical inducer of disease resistance 总被引:2,自引:0,他引:2
123.
Masaki Kanamori Ken-ichiro Saitoh Tsutomu Arie Takashi Kamakura Tohru Teraoka 《Journal of General Plant Pathology》2005,71(4):253-262
The rice blast fungus Magnaporthe grisea differentiates appressoria, which are required to attack its rice plant host. Clone A26, tentatively named LPL1, was previously found to be homologous to the known lysophospholipase genes from our subtractive cDNA library. The LPL1 protein had a consensus motif (GxSxG) and a catalytic triad (S, D, H) of esterases in the deduced amino acid sequence, and the protein expressed in Escherichia coli had lysophospholipase activity. To clarify the functions and possible roles of LPL1, the gene was disrupted by targeted gene replacement. The ΔLPL1 mutants formed fewer appressoria on the hydrophobic surface of GelBond film, and the appressoria had reduced turgor pressure and penetration into cells of the leaf sheath. The ΔLPL1 mutants and wild-type differentiated normal appressoria on other artificial substrata such as polycarbonate plate and on rice leaf sheath. Cytological analysis of the appressoria indicated that ΔLPL1 mutants had a delay in the disappearance of lipid droplets. These findings imply that LPL1, phospholipid metabolism, or both are involved in glycerol biosynthesis and accumulation to generate turgor pressure in the appressorium. LPL1 was, however, dispensable for full pathogenicity, suggesting that other complementary pathways or similar genes related to phospholipid metabolism probably function in M. grisea. 相似文献
124.
Masaki Shimono Makoto Ino Shoji Sonoda Tatsuhito Fujimura Masamichi Nishiguchi 《Journal of General Plant Pathology》2005,71(2):147-152
Nicotiana benthamiana was transformed with a green fluorescent protein (GFP) gene driven by cauliflower mosaic virus 35S promoter. A GFP-silenced line and a nonsilenced line were selected after ultraviolet irradiation. GFP short-interfering RNAs (siRNAs) were detected in the silenced line but not in the nonsilenced line. T1 progeny of the silenced line varied in GFP suppression patterns and were grouped into three types (I, II, III) based on the GFP suppression pattern. With Northern blot analysis, different levels of GFP mRNA accumulated, from a very low level in type I and II to an intermediate level in type III, in contrast to a much higher level in the nonsilenced line. Plants were also inoculated with Potato virus X engineered to contain the GFP sequence to evaluate the levels of virus resistance. None to a few GFP spots were observed on inoculated leaves in types I and II, whereas numerous spots and systemic infection appeared in type III. These results showed that virus resistance was inversely correlated with the levels of mRNA, suggesting that the strength of RNA silencing determines the extent of virus resistance. 相似文献
125.
ABSTRACT When Ipomoea nil was coinfected with Sweet potato feathery mottle virus (SPFMV), a member of the genus Potyvirus, and Potato virus X (PVX) typical symptoms caused by PVX were observed on those by SPFMV on the first upper true leaves at 14 days postinoculation (dpi). On the other hand, no PVX-induced symptoms were observed on the first upper true leaves at 14 dpi when plants were infected with PVX alone. In the case of coinfection with PVX and SPFMV, PVX RNA was detected not only in the inoculated cotyledonary leaves but also in the first upper true leaves at 14 dpi. In the case of single infection with PVX, PVX RNA was detected in the inoculated cotyledonary leaves but not in the first upper true leaves at 14 dpi. The accumulation of SPFMV remained unchanged, regardless of whether the inoculum consisted of SPFMV alone or a mixture of SPFMV and PVX. Although recombinant PVX engineered to express the helper component-proteinase (HC-Pro) of SPFMV (PVX.HC) enhanced symptoms severity in Nicotiana benthamiana, PVX.HC induced the synergism characterized by an enhanced viral movement in Ipomoea nil. Immunofluorescence microscopic examination revealed that the HC-Pro was present in phloem of SPFMV-infected I. nil. These results suggest that SPFMV HC-Pro acts as an enhancer of long distance movement for PVX in I. nil. 相似文献
126.
Impact of bark stripping by sika deer, Cervus nippon, on subalpine coniferous forests in central Japan 总被引:7,自引:0,他引:7
Shotaro Yokoyama Ikuyo Maeji Tsuyoshi Ueda Masaki Ando Eiichi Shibata 《Forest Ecology and Management》2001,140(2-3):93-99
We investigated the effect of bark stripping by sika deer, Cervus nippon, on forest regeneration in subalpine coniferous forests on Mt. Ohdaigahara and in the Ohmine Mountains of central Japan. Bark stripping by sika deer occurred in five major tree species: Abies homolepis; Abies Veitchii; Tsuga diversifolia; Picea jezoensis var. hondoensis; and Chamaecyparis obtusa. The percentage of damaged trees on Mt. Ohdaigahara was higher than in the Ohmine Mountains, probably because of the higher deer density. On Mt. Ohdaigahara, the DBH distributions of stems for P. jezoensis var. hondoensis, A. homolepis, T. diversifolia andC. obtusa were bell-shaped with fewer smaller and larger trees. On the other hand, in the Ohmine Mountains the distributions for P. jezoensis var. hondoensis and A. Veitchii showed a reverse-J shaped with more smaller trees. Larger overstory conifers on Mt. Ohdaigahara were killed by bark stripping when 100% barked, although in the Ohmine Mountains ca. 50% of the trees survived even when 100% barked. After the disappearance of the overstory conifers on Mt. Ohdaigahara, the dwarf bamboo, Sasa nipponica, expanded into the forest floor due to changes in light reaching the forest floor. Since S. nipponica is the main forage of deer in this area, this increase caused a corresponding increase in the deer population, which in turn, could cause a further decline in the coniferous forests. 相似文献
127.
Toshikazu Takeuchi Takashi Sugaya Ayako Kanazashi Hiroshi Yoshimaru Masaki Katsuta 《Journal of Forest Research》2001,6(3):157-162
The genetic diversity of the mangrove tree speciesKandelia candel andBruguiera gymnorrhiza in the Southwest Islands of Japan was investigated. These islands are located at the periphery of the distribution area of
the two species, and their populations are relatively small. Allozyme analyses of 17 loci inK. candel and 13 loci inB. gynmorrhiza revealed very little genetic variation in both species. At the species level, the proportion of polymorphic loci was 4.2%,
the average effective number of alleles per locus was 1.02, and the average expected heterozygosity was 0.012 inK. candel. The corresponding figures forB. gymnorrhiza were 9.0%, 1.06 and 0.035, respectively. However, the coefficients of genetic differentiation among the populations were
high (G
ST=0.165 forK. candel and 0.253 forB. gymnorrhiza). The genetic variation and habitat area ofK. candel on Amami Island is greater than on the islands Okinawa and Iriomote. The genetic variation and habitat area ofB. gymnorrhiza is greater on Iriomote Island than on the islands Okinawa and Amami. The level of genetic variation in both of the species
might be related to their population sizes. 相似文献
128.
Tomoyuki Hayashi Atsushi Miyatake Feng Fu Hideo Kato Masahiko Karube Masaki Harada 《Journal of Wood Science》2005,51(5):486-491
To investigate the durability of structural laminated veneer lumber (LVL), outdoor exposure tests have been conducted since
1990 at a field-testing site at the Forestry and Forest Products Research Institute. This article is the second interim report
on the results after 9 years of exposure. Seven kinds of structural LVL with no preservative treatment were subjected to the
tests. Almost all the exposed specimens were decayed by a kind of brown rot fungi (Pseudomerulius aureus (Fr.) Julich). The degree of decay varied with wood species; grand fir and western hemlock LVL in particular showed weak
resistance against the decay. All the specimens were stored for more than 1 year in a testing room conditioned at 20°C and
65% relative humidity. We then measured the ultrasonic velocity of the specimens by the Pundit method, penetration depth by
the Pilodyn method, and bending strength by a conventional bending test. Correlation between nondestructive measurement factors
and the density was strong even on LVL with many adhesive layers. The nondestructive testing method was found to be applicable
to LVL as well as solid lumber. After the nondestructive measurements, each LVL was cut into three types of specimen (top:
T, middle: M, and bottom: B) for the bending tests. The bending strength varied with the type of specimens. Correlation between
modulus of elasticity and modulus of rupture was strong even in the decayed specimens. 相似文献
129.
To confirm that freeze-thaw embolism is a primary stress for evergreen woody species in winter, hydraulic conductivity, photosynthesis and leaf water potential were measured during fall and winter in trees growing in a cool temperate zone (Nikko) and in a warm temperate zone (Tokyo). We examined two evergreen conifers that naturally occur in the cool temperate zone (Abies firma Siebold & Zucc. and Abies homolepis Siebold & Zucc.), and four evergreen broad-leaved woody species that are restricted to the warm temperate zone (Camellia japonica L., Cinnamomum camphora (L.) J. Presl, Ilex crenata Thunb. and Quercus myrsinaefolia Blume). In Tokyo, where no freeze-thaw cycles of xylem sap occurred, hydraulic conductivity, photosynthesis and water balance remained constant during the experimental period. In Nikko, where there were 38 daily freeze-thaw cycles by February, neither of the tracheid-bearing evergreen conifers showed xylem embolism or leaf water deficits. Similarly, the broad-leaved evergreen trees with small-diameter vessels did not exhibit severe embolism or water deficits and maintained CO(2) assimilation even in January. In contrast, the two broad-leaved evergreen trees with large-diameter vessels showed significantly reduced hydraulic conductivity and shoot die-back in winter. We conclude that freeze-thaw embolism restricts evergreen woody species with large-diameter vessels to the warm temperate zone, whereas other stresses limit the distribution of broad-leaved trees, that have small-diameter vessels, but which are restricted to the warm temperate zone. 相似文献
130.
Masaki Fukuda Izumi Sendo Satoko Imahori Yukitaka Fukumasa-Nakai 《Journal of Wood Science》2007,53(3):264-267
Electrophoretic analysis of the transmission pattern of mitochondrial plasmids in protoplast cell fusion between compatible
monokaryons of Lentinula edodes indicates that three of the four plasmids carried in parental monokaryons are effectively transferred and replicated in the
protoplast fusants. The two monokaryons, 1158a and 1569a, carried different plasmids that could be distinguished by a single
restriction digest. Electrophoresis of intact plasmids and restriction analyses indicate that all but one of the fusants carry
three of the four possible plasmids, indicating that transmission of plasmids in protoplast fusions is principally biparental
in L. edodes. Thus, heterocytoplasmic cells of L. edodes can be effectively constructed by protoplast cell fusion. In addition, plasmids of the same homology group cannot coexist
in the heteroplasmic cells after protoplast cell fusion.
Contribution No. 382 of the Tottori Mycological Institute 相似文献