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31.
Alternaria alternata is a common fungal parasite on fruits and other plants and produces a number of mycotoxins, including alternariol (3,7,9-trihydroxy-1-methyl-6H-dibenzo [b,d]pyran-6-one), alternariol monomethyl ether (3,7-dihydroxy-9-methoxy-1-methyl-6H-dibenzo[b,d]pyran-6-one), and the mutagen altertoxin I {[1S-(1α,12aβ,12bα)] 1,2,11,12,12a, 12b-hexahydro-1,4,9,12a-tetrahydroxy-3,10-perylenedione}.
Alternariol and alternariol monomethyl ether have previously been detected in some samples of fruit beverages. Stability studies
of these toxins as well as altertoxin I added to fruit juices and wine (10–100 ng/mL) were carried out. To include altertoxin
I in the analysis, cleanup with a polymer-based Varian Abselut solid phase extraction column was used, as recoveries from
C-18 columns were low. The stabilities of alternariol and alternariol monomethyl ether in a low acid apple juice containing
no declared vitamin C were compared with those in the same juice containing added vitamin C (60 mg/175 ml); there were no
apparent losses at room temperature over 20 days or at 80°C after 20 min. in either juice. Altertoxin I was moderately stable
in pH 3 buffer (75% remaining after a two week period). Furthermore, altertoxin I was stable or moderately stable in three
brands of apple juice tested over 1–27 day periods and in a sample of red grape juice over 7 days. It is concluded that altertoxin
I is sufficiently stable to be found in fruit juices and should be included in methods for alternariol and alternariol monomethyl
ether. 相似文献
32.
33.
Aria Dolatabadian Seyed Ali Mohammad Modarres Sanavy Faezeh Ghanati Peter M. Gresshoff 《World journal of microbiology & biotechnology》2013,29(7):1327-1339
We evaluated response differences of normal and transformed (so-called ‘hairy’) roots of soybean (Glycine max L. (Merr.), cv L17) to the Nod-factor inducing isoflavone genistein and salinity by quantifying growth, nodulation, nitrogen fixation and biochemical changes. Composite soybean plants were generated using Agrobacterium rhizogenes-mediated transformation of non-nodulating mutant nod139 (GmNFR5α minus) with complementing A. rhizogenes K599 carrying the wild-type GmNFR5α gene under control of the constitutive CaMV 35S promoter. We used genetic complementation for nodulation ability as only nodulated roots were scored. After hairy root emergence, primary roots were removed and composite plants were inoculated with Bradyrhizobium japonicum (strain CB1809) pre-induced with 10 μM genistein and watered with NaCl (0, 25, 50 and 100 mM). There were significant differences between hairy roots and natural roots in their responses to salt stress and genistein application. In addition, there were noticeable nodulation and nitrogen fixation differences. Composite plants had better growth, more root volume and chlorophyll as well as more nodules and higher nitrogenase activity (acetylene reduction) compared with natural roots. Decreased lipid peroxidation, proline accumulation and catalase/peroxidase activities were found in ‘hairy’ roots under salinity stress. Genistein significantly increased nodulation and nitrogen fixation and improved roots and shoot growth. Although genistein alleviated lipid peroxidation under salinity stress, it had no significant effect on the activity of antioxidant enzymes. In general, composite plants were more competitive in growth, nodulation and nitrogen fixation than normal non-transgenic even under salinity stress conditions. 相似文献
34.
35.
Identification of DNA amplification fingerprinting (DAF) markers close to the symbiosis-ineffective sym31 mutation of pea (Pisum sativum L.) 总被引:1,自引:0,他引:1
A. E. Men A. Y. Borisov S. M. Rozov K. V. Ushakov V. E. Tsyganov I. A. Tikhonovich P. M. Gresshoff 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(6-7):929-936
We demonstrate efficient genome mapping through a combination of bulked segregant analysis (BSA) with DNA amplification fingerprinting
(DAF). Two sets of 64 octamer DAF primers, along with two PCR programs of low- and high-annealing temperatures (30°C and 55°C,
respectively), appeared to be enough to locate molecular markers within 2–5 cM of a gene of interest. This approach allowed
the rapid identification of four BSA markers linked to the pea (Pisum sativum L.) Sym31 gene, which is responsible for bacteroid and symbiosome differentiation. Three of these markers are shown to be tightly linked
to the sym31 mutation. Two markers flanking the Sym31 gene, A21-310 and B1-277, cover a 4–5 cM interval of pea linkage group 3. Both markers were converted to sequence-characterized
amplified regions (SCARs). The flanking markers may be potential tools for marker-assisted selection or for positional cloning
of the Sym31 gene.
Received: 2 July 1998 / Accepted: 8 October 1998 相似文献
36.
37.
A Maarten J Kootstra Hendrik H Beeftink Elinor L Scott Johan PM Sanders 《Biotechnology for biofuels》2009,2(1):31-14
Background
In this study, the dilute maleic acid pretreatment of wheat straw is optimized, using pretreatment time, temperature and maleic acid concentration as design variables. A central composite design was applied to the experimental set up. The response factors used in this study are: (1) glucose benefits from improved enzymatic digestibility of wheat straw solids; (2) xylose benefits from the solubilization of xylan to the liquid phase during the pretreatment; (3) maleic acid replenishment costs; (4) neutralization costs of pretreated material; (5) costs due to furfural production; and (6) heating costs of the input materials. For each response factor, experimental data were fitted mathematically. After data translation to €/Mg dry straw, determining the relative contribution of each response factor, an economic optimization was calculated within the limits of the design variables. 相似文献38.
Lee WK Jeong N Indrasumunar A Gresshoff PM Jeong SC 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(5):875-884
The rj1 mutation of soybean is a simple recessive allele in a single line that arose as a spontaneous mutation in a population; it
exhibits non-nodulation with virtually all Bradyrhizobium and Sinorhizobium strains. Here, we described fine genetic and physical mapping of the rj1 locus on soybean chromosome 2. The initial mapping of the rj1 locus using public markers indicated that A343.p2, a sequence-based marker that contains sequence similar to a part of the
LjNFR1 gene regulating nodule formation as a member of lysin motif-type receptor-like kinase (LYK) family, maps very close to or
cosegregates with the rj1 locus. The sequence of A343.p2 is 100% identical to parts of two BAC clone sequences (GM_WBb0002O19 and GM_WBb098N11) that
contain three members of the LYK family. We analyzed the sequence contig (262 kbp) of the two BAC clones by resequencing and subsequent fine genetic and physical
mapping. The results indicated that rj1 is located in a gene-rich region with a recombination rate of 120 kbp/cM: several fold higher than the genome average. Among
the LYK genes, NFR1α is most likely the gene encoded at the Rj1 locus. The non-nodulating rj1 allele was created by a single base-pair deletion that results in a premature stop codon. Taken together, the fine genetic
and physical mapping of the Rj1-residing chromosomal region, combined with the unexpected observation of a putative recombination hotspot, allowed us to
demonstrate that the Rj1 locus most likely encodes the NFR1α gene. 相似文献
39.
Brett J. Ferguson Dongxue Li April H. Hastwell Dugald E. Reid Yupeng Li Scott A. Jackson Peter M. Gresshoff 《Plant biotechnology journal》2014,12(8):1085-1097
Legume plants regulate the number of nitrogen‐fixing root nodules they form via a process called the Autoregulation of Nodulation (AON). Despite being one of the most economically important and abundantly consumed legumes, little is known about the AON pathway of common bean (Phaseolus vulgaris). We used comparative‐ and functional‐genomic approaches to identify central components in the AON pathway of common bean. This includes identifying PvNARK, which encodes a LRR receptor kinase that acts to regulate root nodule numbers. A novel, truncated version of the gene was identified directly upstream of PvNARK, similar to Medicago truncatula, but not seen in Lotus japonicus or soybean. Two mutant alleles of PvNARK were identified that cause a classic shoot‐controlled and nitrate‐tolerant supernodulation phenotype. Homeologous over‐expression of the nodulation‐suppressive CLE peptide‐encoding soybean gene, GmRIC1, abolished nodulation in wild‐type bean, but had no discernible effect on PvNARK‐mutant plants. This demonstrates that soybean GmRIC1 can function interspecifically in bean, acting in a PvNARK‐dependent manner. Identification of bean PvRIC1, PvRIC2 and PvNIC1, orthologues of the soybean nodulation‐suppressive CLE peptides, revealed a high degree of conservation, particularly in the CLE domain. Overall, our work identified four new components of bean nodulation control and a truncated copy of PvNARK, discovered the mutation responsible for two supernodulating bean mutants and demonstrated that soybean GmRIC1 can function in the AON pathway of bean. 相似文献
40.
Inoculation of soybean (Glycine max. cv. Bragg) plants with high level inoculum partially alleviated the nitrate inhibition of nodule formation (3 to 4 fold), but not nodule growth. This alleviation did not require the bacterial nitrate reductase asBradyrhizobium japonicum mutant strains 110CR1 and 110CR2 (both lacking assimilatory nitrate reductase activity) gave the same results as the wild type parent 311b110. The study was carried out in the glasshouse, thereby confirming preliminary field data by Herridgeet al. (1984) using a wild type bacterial inoculant. 相似文献