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Gauri Saxena Suchitra Banerjee Laiq-ur-Rahman Praveen Chandra Verma G. R. Mallavarapu Sushil Kumar 《Plant Cell, Tissue and Organ Culture》2007,90(2):215-223
Transgenic plants of rose-scented geranium (Pelargonium graveolens cv. Hemanti) have been produced from Agrobacterium rhizogenes (strains A4 and LBA9402) mediated hairy root cultures. Amongst the explants tested, leaves were most responsive followed by the petioles
and internodal segments, respectively. The A4 strain performed better for all the three explants both in terms of frequency of response and time requirement for hairy
root induction. Transgenic shoots could be obtained by spontaneous regeneration without intervening callus phase amongst 16%
and 12% root lines of A4 and LBA 9402 origin, respectively, or they were induced in 29% and 22% hairy root lines of A4 and LBA9402 origin, respectively, with different hormonal supplementation. These transgenic plants showed 30% survival as
against 90% of their control under the confined environment of glasshouse. The transgenic plants were of similar morphotype
having increased branching, higher number of leaves with increased dentations, short and round stature, highly branched root
system and absence of leaf wrinkling. These transgenic plants showed opine positive results even after 5 months of their transfer
to the glasshouse. The essential oil compositions of 81% of these transgenics were qualitatively similar to that of the wild
type parent. However, two transgenic plants (LZ-3 and 14TG) showed increase in concentrations of geraniol and geranyl esters
signifying improved oil quality with respect to the citronellol:geraniol ratio. These two oils having better olfactory value
represent an improvement over that of the wild type parent from the commercial point of view. 相似文献
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FLOWERING LOCUS T (FT) like genes are crucial regulators (both positive and negative) of flowering in angiosperms. We identified two FT homologs in Chenopodium rubrum, a short-day species used as a model plant for the studies of photoperiodic flower induction. We found that CrFTL1 gene was highly inducible by a 12-h dark period, which in turn induced flowering. On the other hand, photoperiodic treatments
that did not induce flowering (short dark periods, or a permissive darkness interrupted by a night break) caused only a slight
increase in CrFTL1 mRNA level. We demonstrated diurnal oscillation of CrFTL1 expression with peaks in the middle of a light period. The oscillation persisted under constant darkness. Unlike FT homologs in rice and Pharbitis, the CrFTL1 expression under constant darkness was very low. The CrFTL2 gene showed constitutive expression. We suggest that the CrFTL1 gene may play a role as a floral regulator, but the function of CrFTL2 remains unknown. 相似文献
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Lopes Ferreira N Mathis H Labbé D Monot F Greer CW Fayolle-Guichard F 《Applied microbiology and biotechnology》2007,75(4):909-919
Mycobacterium austroafricanum IFP 2012, which grows on methyl tert-butyl ether (MTBE) and on tert-butyl alcohol (TBA), the main intermediate of MTBE degradation, also grows on a broad range of n-alkanes (C2 to C16). A single alkB gene copy, encoding a non-heme alkane monooxygenase, was partially amplified from the genome of this bacterium. Its expression
was induced after growth on n-propane, n-hexane, n-hexadecane and on TBA but not after growth on LB. The capacity of other fast-growing mycobacteria to grow on n-alkanes (C1 to C16) and to degrade TBA after growth on n-alkanes was compared to that of M. austroafricanum IFP 2012. We studied M. austroafricanum IFP 2012 and IFP 2015 able to grow on MTBE, M. austroafricanum IFP 2173 able to grow on isooctane, Mycobacterium sp. IFP 2009 able to grow on ethyl tert-butyl ether (ETBE), M. vaccae JOB5 (M. austroaafricanum ATCC 29678) able to degrade MTBE and TBA and M. smegmatis mc2 155 with no known degradation capacity towards fuel oxygenates. The M. austroafricanum strains grew on a broad range of n-alkanes and three were able to degrade TBA after growth on propane, hexane and hexadecane. An alkB gene was partially amplified from the genome of all mycobacteria and a sequence comparison demonstrated a close relationship
among the M. austroafricanum strains. This is the first report suggesting the involvement of an alkane hydroxylase in TBA oxidation, a key step during
MTBE metabolism. 相似文献
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The nucleotide sequences of ten SP11 and nine SRK alleles in Raphanus sativus were determined, and deduced amino acid sequences were compared with those of Brassica SP11 and SRK. The amino acid sequence identity of class-I SP11s in R. sativus was about 30% on average, the highest being 52.2%, while that of the S domain of class-I SRK was 77.0% on average and ranged from 70.8% to 83.9%. These values were comparable to those of SP11 and SRK in Brassica oleracea and B. rapa. SP11 of R. sativus S-21 was found to be highly similar to SP11 of B. rapa S-9 (89.5% amino acid identity), and SRK of R. sativus S-21 was similar to SRK of B. rapa S-9 (91.0%). SP11 and SRK of R. sativus S-19 were also similar to SP11 and SRK of B. oleracea S-20, respectively. These similarities of both SP11 and SRK alleles between R. sativus and Brassica suggest that these S haplotype pairs originated from the same ancestral S haplotypes. 相似文献
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The synthesis of optically active (R)-2-trimethylsilyl-2-hydroxyl-ethylcyanide by asymmetric trans-cyanation of acetyltrimethylsilane with acetone cyanohydrin in a biphasic system was achieved using (R)-oxynitrilase from loquat seed meal. Diisopropyl ether was the most suitable organic phase among the organic solvents examined. The optimal concentration of acetyltrimethylsilane, concentration of crude enzyme, volume ratio of the aqueous to the organic phase, temperature and the buffer pH value were 14 mM, 61.4 U ml-1, 13% (v/v), 30 °C and 4, respectively. The substrate conversion and the product enantiomeric excess were 95% and 98% under the optimized conditions. Acetyltrimethylsilane was a better substrate of the enzyme than its carbon counterpart.
Revisions requested 24 August 2004; Revisions received 12 November 2004 相似文献
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The present study aimed to obtain analgesic-antitumor peptide (AGAP) gene expression in plants. The analgesic-antitumor peptide (AGAP) gene was from the venom of Buthus martensii Karsch. Previous studies showed that AGAP has both analgesic and antitumor activities, suggesting that AGAP would be useful in clinical situations as an antitumor drug. Given that using a plant as an expression vector has more advantages
than prokaryotic expression, we tried to obtain transgenic plants containing AGAP. In the present study, the AGAP gene was cloned into the plasmid pBI121 to obtain the plant expression vector pBI-AGAP. By tri-parental mating and freeze–thaw transformation, pBI-AGAP was transformed into Agrobacterium tumefaciens LBA4404. Tobacco (Nicotiana tabacum) and tomato (Lycopersicom esculentum) were transformed by the method of Agrobacterium-mediated leaf disc transformation. The transformants were then screened to grow and root on media containing kanamycin. Finally,
transformations were confirmed by analysis of PCR, RT-PCR and western blotting. The results showed that the AGAP gene was integrated into the genomic DNA of tobacco and tomato and was successfully expressed. Therefore, the present study
suggests a potential industrial application of AGAP expressed in plants. 相似文献
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Phytochelatins (PCs) are post-translationally synthesized thiol reactive peptides that play important roles in detoxification
of heavy metal and metalloids in plants and other living organisms. The overall goal of this study is to develop transgenic
plants with increased tolerance for and accumulation of heavy metals and metalloids from soil by expressing an Arabidopsis
thaliana
AtPCS1 gene, encoding phytochelatin synthase (PCS), in Indian mustard (Brassica juncea L.). A FLAG-tagged AtPCS1 gDNA, under its native promoter, is expressed in Indian mustard, and transgenic pcs lines have been compared with wild-type
plants for tolerance to and accumulation of cadmium (Cd) and arsenic (As). Compared to wild type plants, transgenic plants
exhibit significantly higher tolerance to Cd and As. Shoots of Cd-treated pcs plants have significantly higher concentrations
of PCs and thiols than those of wild-type plants. Shoots of wild-type plants accumulated significantly more Cd than those
of transgenic plants, while accumulation of As in transgenic plants was similar to that in wild type plants. Although phytochelatin
synthase improves the ability of Indian mustard to tolerate higher levels of the heavy metal Cd and the metalloid As, it does
not increase the accumulation potential of these metals in the above ground tissues of Indian mustard plants. 相似文献
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The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
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Zhang J Chen R Xiao J Qian C Wang T Li H Ouyang B Ye Z 《Journal of plant research》2007,120(6):671-678
The entire (e) locus of tomato (Solanum lycopersicum L.) controls leaf morphology. Dominant E and recessive e allele of the locus produce pinnate compound and complex reduced leaves. Previous research had indicated that SlIAA9, an Aux/IAA gene, was involved in tomato leaf morphology. Down-regulation of SlIAA9 gene by antisense transgenic method decreased the leaf complex of tomato and converted tomato compound leaves to simple leaves.
The leaf morphology of these transgenic lines was similar with leaf morphology of tomato entire mutant. In this paper, we report that a single-base deletion mutation in the coding region of SlIAA9 gene results in tomato entire mutant phenotypes. 相似文献
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Two litchi cultivars, a well-coloured ‘Nuomici’ and a poorly coloured ‘Feizixiao’, were used to investigate changes in endogenous
abscisic acid (ABA) concentration and ethylene production during fruit maturation and to test the effects of exogenous growth
regulators on litchi fruit maturation. Abscisic acid concentration in both the aril and pericarp increased with fruit maturation.
Transfusion of ABA into the fruit 3 weeks before harvest accelerated, whereas transfusion of 6-benzyl aminopurine (6-BA) retarded
sugar accumulation and pigmentation. The effect of 6-BA was assumed to link with the resultant decrease in ABA. In contrast,
1-aminocyclopropane-1-carboxylic acid (ACC) concentration and ACC oxidase (ACO) activities in the aril remained relatively
constant during sugar accumulation. Transfusion of aminooxyacetic acid (AOA) significantly decreased ACC concentration but
had no effect on sugar accumulation in the aril. These results suggested that endogenous ABA, but not ethylene, was critical
for the sugar accumulation. However, the roles of ABA and ethylene in pericarp pigmentation were rather complicated. Application
of exogenous ABA promoted anthocyanin synthesis significantly, but had very little effect on chlorophyll degradation. Ethylene
production in litchi fruit decreased with development, but a transient increase of endogenous ethylene production was detected
just around the colour break in ‘Nuomici’. Enhanced ACO activity in the pericarp was detected during pigmentation. Ethrel
at 400 mg l−1 showed no effect on pericarp coloration, but accelerated chlorophyll degradation and anthocyanin synthesis at a much higher
concentration (800 mg l−1). Fruit dipped in ABA solution alone yielded no effect on chlorophyll degradation, but the combined use of ABA and Ethrel
at 400 mg l−1 enhanced both chlorophyll degradation and anthocyanin synthesis. These results indicated the possible synergistic action
of ethylene and ABA during litchi fruit colouration. ABA is suggested to play a more crucial role in anthocyanin synthesis,
while ethylene is more important in chlorophyll degradation. ABA can increase the sensitivity of pericarp tissue to ethylene. 相似文献
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Thilo C. Fischer Christian Gosch Judith Pfeiffer Heidrun Halbwirth Christian Halle Karl Stich Gert Forkmann 《Trees - Structure and Function》2007,21(5):521-529
Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation. Pear flavonoids contribute to its fruit
color, pathogen defense, and are health beneficial ingredients of the fruits. Comparative Southern analyses with apple (Malus x domestica) cDNAs showed comparable genomic organization of flavonoid genes of both related genera. A homology-based cloning approach
was used to obtain the cDNAs of most enzymes of the main flavonoid pathway of Pyrus: phenylalanine ammonia lyase, chalcone synthase, chalcone isomerase, flavanone 3β-hydroxylase, flavonol synthase, dihydroflavonol
4-reductase, leucoanthocyanidin reductase 1 and 2, anthocyanidin synthase, anthocyanidin reductase, and UDP-glucose : flavonoid
7-O-glucosyltransferase. The substrate specificities of the recombinant enzymes expressed in yeast were determined for physiological
and non-physiological substrates and found to be in general agreement with the characteristic pear flavonoid metabolite pattern
of mainly B-ring dihydroxylated anthocyanins, flavonols, catechins, and flavanones. Furthermore, significant differences in
substrate specificities and gene copy numbers in comparison to Malus were identified. Cloning of the cDNAs and studying the enzymes of the Pyrus flavonoid pathway is an essential task toward a comprehensive knowledge of Pyrus polyphenol metabolism. It also elucidates evolutionary patterns of flavonoid/polyphenol pathways in the Rosaceae, which allocate
several important crop plants. 相似文献
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Fanna Kong Shaomei Jiang Xiangbing Meng Chengli Song Jinfeng Shi Demin Jin Shaolin Jiang Bin Wang 《Plant Molecular Biology Reporter》2009,27(2):199-208
Dihydrodipicolinate synthase (DHDPS) is the main enzyme of a specific branch of the aspartate pathway leading to lysine biosynthesis
in higher plants. We have cloned and characterized the DHDPS gene from Zizania latifolia Griseb, which was named ZlDHDPS. Sequence analysis indicates that it contains an ORF of 954 bp interrupted by two exons and one intron encoding a polypeptide
of 317 amino acids lacking a plastid transit peptide and a stop codon. The sequence of ZlDHDPS has high identity with known
plant DHDPS in GenBank. Southern blotting analysis indicates that there are two copies of Z. latifolia DHDPS (ZlDHDPS) gene in the Z. latifolia nuclear genome. RT-PCR analysis shows the expression of ZlDHDPS is tissue specific and high level expression is present in fast-growing tissue and reproductive tissue. The 5′-regulatory
sequence of ZlDHDPS contains a GT-1 box and a (CA)n element, which may play a role in regulating the expression of ZlDHDPS. The fusion construct of the ZlDHDPS sequence with the reporter gene GUS was transiently expressed in the onion epidermal cells by particle gun-mediated bombardment
suggesting that ZlDHDPS was located in the cytoplasm, different from DHDPS gene of other species. Functional complementary analysis showed that ZlDHDPS can recover the DHDPS-deleted mutant of Escherichia coli. 相似文献
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Ryoo N Yu C Park CS Baik MY Park IM Cho MH Bhoo SH An G Hahn TR Jeon JS 《Plant cell reports》2007,26(7):1083-1095
To elucidate the role of SSIIIa during starch synthesis in rice (Oryza sativa L.) endosperm, we characterized null mutants of this gene, generated by T-DNA insertions. Scanning electron microscope (SEM)
analysis revealed that the starch granules in these mutants are smaller and rounder compared with the wild type controls,
and that the mutant endosperm is characterized by a loosely packed central portion exhibiting a floury-like phenotype. Hence,
the OsSSIIIa (Oryza sativa SSIIIa) mutations are referred to as white-core floury endosperm 5-1 (flo5-1) and flo5-2. Based upon their X-ray diffraction patterns, the crystallinity of the starch in the flo5 mutant endosperm is decreased compared with wild type. Through determination of the chain-length distribution of the mutant
endosperm starch, we found that flo5-1 and flo5-2 mutants have reduced the content of long chains with degree of polymerization (DP) 30 or greater compared with the controls.
This suggests that OsSSIIIa/Flo5 plays an important role in generating relatively long chains in rice endosperm. In addition,
DP 6 to 8 and DP 16 to 20 appeared to be reduced in endosperm starch of flo5-1 and flo5-2, whereas DP 9 to 15 and DP 22 to 29 were increased in these mutants. By the use of differential scanning calorimetry (DSC),
the gelatinization temperatures of endosperm starch were found to be 1–5°C lower than those of the control. We propose a distinct
role for OsSSIIIa/Flo5 and the coordinated action of other SS isoforms during starch synthesis in the seed endosperm of rice. 相似文献
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Arachis correntina (Burkart) Krapov. & W.C. Gregory is a herbaceous perennial leguminous plant growing in the Northeast of the Province Corrientes, Argentina. It is important as forage. The development of new A. correntina cultivars with improved traits could be facilitated through the application of biotechnological strategies. The purpose of this study was to investigate the plant regeneration potential of mature leaves of A. correntina in tissue culture. Buds were induced from both petiole and laminae on 0.7% agar-solidified medium containing 3% sucrose, salts and vitamins from Murashige and Skoog (MS) supplemented with 0.5–25 M thidiazuron (TDZ). Shoot induction was achieved by transference of calli with buds to MS supplemented with 5 M TDZ. Fifty-four percent of the regenerated shoot rooted on MS + 5 M naphthaleneacetic acid. Histological studies revealed that shoots regenerated via organogenesis. 相似文献
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Francesca Marini Barbara Franzetti Alessandro Calabrese Sara Cappellini Stefano Focardi 《European Journal of Wildlife Research》2009,55(2):107-115
The use of line transect methodology and portable thermal imaging for ground survey of wildlife should require a good knowledge
of the behavioural response of the animals to the presence of an observer, in order to take into account the potential bias
in density estimate caused by deviation from the assumption that distances are recorded at the initial position. We used ten
fallow deer and eight wild boar fitted with radiocollars to investigate animals’ response during simulated nocturnal line
transect surveys, carried out in a Mediterranean plain forest. The experiment consisted in radiolocating a focal animal before
and after an observer walked a transect nearby (<100 m). Each transect line was followed using a Global Positioning System
(GPS) navigator. We carried out a total of 64 trials on fallow deer and 57 on wild boar. Results showed that despite most
of the animals moved significantly in response to the observer (mean ± standard error, wild boar—95.3 ± 10.0 m; fallow deer—149.6 ± 14.2 m),
the flying patterns were different in the two species: the reaction of fallow deer turned out to be more intense and directional
with respect to that showed by wild boar. Although these results sound explorative, the experiment attempted here, for the
first time, is relevant for an appropriate design of nocturnal distance-sampling surveys and gives information about potential
bias arising from animal’s behavioural response. We believe that these first results may foster more in-deep analyses which
are now made possible with the adoption of GPS technology for animal location. 相似文献
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Paranosema (Nosema) locustae Canning has persisted in grasshopper populations in the Inner Mongolia Rangeland since spore treatment was applied in 1993.
In the treatment year, a 58.32–71.43% reduction of grasshoppers was recorded and 59.26–80.36% of surviving grasshoppers of
various species were infected. In the years following application, prevalence of P. locustae varied from 13.65% to 60.71%, demonstrating that P. locustae remains in grasshopper populations for many years. Infection prevalence was more than 60.00% for Dasyhippus barbipes (F.-W.), Bryodema luctuosum luctuosoma (Stoll) and Angaracris barabensis (Pall.) in 1993 but was very variable, ranging from 20.00% to 60.71% over the subsequent nine years. Disease prevalence was
43.72–60.71% in 1993 and 1994 for Oedaleus asiaticus B.-Bienko and Myrmeleotettix palpalis (Zub.) but gradually declined to approximately 20%, where it remained. Persistence of P. locustae in grasshopper populations may be important in keeping densities below economic thresholds for a number of years after application.
Handling Editor: Helen Roy. 相似文献
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