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91.
92.
Milad Aeini 《Archives Of Phytopathology And Plant Protection》2013,46(12):1466-1474
Chinaberry (Melia azedarach) is a deciduous tree of moderate size, grown throughout warm countries. The plantation of M. azedarach tree improves the environmental condition of the country. During the years 1390–1391, bacterial gall symptoms were observed on chinaberry. The isolation of the causal agent bacteria was done on nutrient agar medium. Approximately 4 weeks after inoculation, galls developed on the chinaberries inoculated with different isolates. The specific primer was designed based on 16S rRNA gene and all isolates amplified 429 bp fragment. To sequence 16S rRNA gene of Shiraz isolates, the universal primer PS16Sf-FAM/PS23Sr was used to amplify 16S rRNA gene. The Iranian isolates of Pseudomonas meliae showed 99.7% similarity to P. meliae (type strain) in the Gene Bank. Based on the rep-PCR results and sequence of 16S rRNA gene, Pseudomonas syringae and Pseudomonas fluorescens were placed in the different groups. 相似文献
93.
94.
L. Adamec 《Biologia Plantarum》1997,39(4):599-606
The uptake of K+ by the leafy shoots of four submersed higher aquatic plants (Elodea canadensis, Ranunculus aquatilis, R. trichophyllus, and
Callitriche hamulata) with different HCO3
- affinity was measured in successive 2-h periods under the conditions of high or low photosynthetic rates (i.e. at pH 7.5
or 10). At pH 7.5 the uptake of K+ by species with the higher HCO3
- affinity (E. canadensis, R. trichophyllus) was significantly faster than that by species with a lower HCO3
- affinity (R. aquatilis, C. hamulata). In the former group of species, the K+ uptake rate at pH 7.5 was 1.7 - 3.5 times higher than at pH 10. At pH 10, the soft-water species, R. aquatilis, had the lowest
net photosynthetic rate (PN) of the three HCO3
- users but, in contrast to the relative hard-water species, R. trichophyllus, showed a small K+ efflux (47 nmol kg-1 s-1). Thus, K+ uptake by shoots was not strictly correlated with PN. A significant K+ efflux (73 - 86 nmol kg-1 s-1) occurred from all HCO3
- users in darkness. The relatively low K+ uptake by the strict CO2 user, C. hamulata, was quite independent of PN and light or darkness. It may be suggested that uptake of K+ by shoots of submersed plants depends on their HCO3
- affinity.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
95.
1. Stressful abiotic conditions and mycorrhizal fungi have both been shown to influence plant quality significantly, yet the interactive effects of these factors on relationships among plants, herbivores, and natural enemies remain unclear. 2. In this study, the results of a factorial field experiment are reported in which the effects of plant stress and mycorrhizae on density and parasitism of three herbivores of Baccharis halimifolia L. were examined. 3. Plant stress was increased by adding salt to the soil, and association with mycorrhizal fungi was increased by inoculating plant roots. 4. Inoculation with mycorrhizal fungi resulted in increased density of all three herbivore species, but the effects of mycorrhizae on parasitism varied by species and with soil salinity levels. For the gall maker Neolasioptera lathami Gagne, mycorrhizae decreased parasitism regardless of soil salinity levels. For the leaf miners Amauromyza maculosa Malloch and Liriomyza trifolii Burgess, mycorrhizae effectively negated the decrease in parasitism resulting from increased salinity. 5. The results of this study show that the effects of mycorrhizae on parasitism may be context dependent, and can be positive or negative depending upon species and environmental conditions. 相似文献
96.
Thomas Rausch Subhash C. Minocha Willy Hilgenberg Günter Kahl 《Physiologia plantarum》1985,63(4):335-344
The in vivo metabolism of L-tryptophan in wound-activated and Agrobacterium tumefaciens , strain C 58, transformed tissues of white potato tubers ( Solanum tuberosum L. cv. Saskia) was investigated. The following metabolites of L-tryptophan were identified in both tissues by co-chromatography with authentic standards in several thinlayer chromotography (TLC) and high pressure liquid chromatographic (HPLC) systems: indole-3-acetic acid (IAA), indole-3-acetaldehyde, indole-3-ethanol, indole-3-acetamide and tryptamine. Labelled indole-3-acetaldoxime was only found in transformed tissue. Crown gall tissue generally incorporated [14 C]-L-tryptophan into precursors of IAA at a distinctly higher rate than did wound tissue. Tryptamine and indole-3-ethanol accumulated about ten-fold more label in crown gall cells than in cells from wounded tissue. The incorporation of radioactivity into indole-3-acetamide as determined by 2 consecutive TLC systems followed by HPLC analysis was rather low, though consistently observed in both tissues. An indole-3-acetamide hydrolyzing enzyme, the putative product of gene 2 on the T-DNA, could be extracted from the transformed tissue only. The indole-3-ethanol level was 4.3 nmol (g dry weight)−1 and 41 nmol (g dry weight)−1 for wounded tissue and primary crown gall tissue, respectively, as determined by HPLC with a [14 C]-labelled internal standard. The experiments are critically discussed in relation to recent reports on a T-DNA encoded enzyme of IAA biosynthesis in crown gall tumors. 相似文献
97.
William Scott Chilton Elizabeth Hood Kenneth L. Rinehart Mary-Dell Chilton 《Phytochemistry》1985,24(12):2945-2948
Alfalfa tumour incited by Agrobacterium tumefaciens strain A281, carrying the tumour inducing plasmid pTi Bo542, synthesizes agropine and related mannityl opines. In addition it contains a small amount of leucinopine and large quantities of a new opine here identified as N-[(1S)-1-carboxy 2-carbamoylethyl]-(S)-glutamic acid. This new opine, L,L-succinamopine, is the Lglu epimer of the succinamopine previously isolated from tumours incited by pTi AT181 and related strains. The latter opine should now be designated D,L-succinamopine. This is the first example of the natural occurrence of epimeric opine structures. 相似文献
98.
99.
Takashi Hirayama Toshiya Muranaka Hideo Ohkawa Atsuhiro Oka 《Molecular & general genetics : MGG》1988,213(2-3):229-237
Summary We have precisely localized virulent (vir) genes of the hairy root-inducing plasmid pRiA4b on the basis of sequence similarity with the tumor-inducing plasmid pTiA6NC, and shown that the overall organizations of vir genes in both plasmids are fairly analogous, although sizes and spacer lengths in some genes differ from each other. Among the vir genes thus mapped, the virC and virD loci were characterized in detail. Transposon insertions in virD led to loss of tumorigenicity on Kalanchoe stems and carrot discs, and one within virC exhibited an attenuated pathogenicity. The avirulent phenotype of the virD2 strain among these mutants was due to the lack of ability to recombine T-DNA border repeats in Agrobacterium cells. The nucleotide sequence of most parts of the virCD loci were similar in both plasmids. The virCD genes of these two plasmids, therefore, seem comparable both functionally and structurally. Phylogeny of pRi and pTi has also been discussed from the sequence data. 相似文献
100.
B. FENTON G. MALLOCH A. T. JONES J. W. AMRINE Jr S. C. GORDON S. A'HARA W. J. MCGAVIN A. N. E. BIRCH 《Molecular ecology》1995,4(3):383-388
Cecidophyopsis mites were studied by PCR amplification of parts of their ribosomal DNA, followed by restriction enzyme analysis. Mite specimens on Ribes nigrum (black currant) from six countries gave the same digestion pattern, which was distinct from the pattern for mites found on R. rubrum from Poland and Finland and for R. grossularia from the USA. This suggests that each Ribes species is host to a different mite species: C. ribis, C. selachodon and C. grossulariae, respectively. Two other mite samples from R. alpinum and R. aureum were identical but were distinct from each of the other species. 相似文献