Altered cytokinin distribution in the shootless maize mutant ed*41

2001 ◽  
Vol 28 (4) ◽  
pp. 307 ◽  
Author(s):  
Adriana Chiappetta ◽  
Walter de Witte ◽  
Milvia L. Racchi ◽  
Maria B. Bitonti ◽  
Henri van Onckelen ◽  
...  
Keyword(s):  
Zea Mays ◽  
Apical Meristem ◽  
Time Course ◽  
Zea Mays L ◽  
Wild Type ◽  
Vascular Connection ◽  
Vascular Tissues ◽  
In The Wild ◽  
Specific Synthesis

The distribution of cytokinins is strongly altered in seedlings of the shootless ed*41 mutant of maize (Zea mays L.), compared with wild-type. Immunolocalisation of zeatin and analysis of cytokinin levels clearly indicate that these hormones are not present in the shoot apex zone of the mutant. Since an anomalous differentiation of vascular tissues has also been observed in the mutant, a major role of vascular connection in hormone translocation affecting development of the shoot apical meristem is proposed. Immunolocalisation of zeatin was confined to the root cap, cortex and vascular tissues of both mutant and wild-type seedlings suggesting a tissue-specific synthesis of this hormone in the root. A time-course of cytokinin distribution in the wild-type developing shoot provided evidence that the tunica and corpus zones become competent to respond to cytokinins in subsequent periods, very probably in conjunction with photomorphogenesis. On the contrary, this pathway is totally disrupted in the mutant. Taken together, the data point to a relationship between the ed*41 mutation, inadequate vascular connection and disrupted hormone translocation.

scholarly journals Transcriptome Changes in Pseudomonas putida KT2440 during Medium-Chain-Length Polyhydroxyalkanoate Synthesis Induced by Nitrogen Limitation

2020 ◽  
Vol 22 (1) ◽  
pp. 152
Author(s):  
Dorota Dabrowska ◽  
Justyna Mozejko-Ciesielska ◽  
Tomasz Pokój ◽  
Slawomir Ciesielski
Keyword(s):  
Chain Length ◽  
Nitrogen Limitation ◽  
Stringent Response ◽  
Wild Type ◽  
Pseudomonas Putida Kt2440 ◽  
Medium Chain ◽  
Environmental Stimuli ◽  
Medium Chain Length ◽  
In The Wild

Pseudomonas putida’s versatility and metabolic flexibility make it an ideal biotechnological platform for producing valuable chemicals, such as medium-chain-length polyhydroxyalkanoates (mcl-PHAs), which are considered the next generation bioplastics. This bacterium responds to environmental stimuli by rearranging its metabolism to improve its fitness and increase its chances of survival in harsh environments. Mcl-PHAs play an important role in central metabolism, serving as a reservoir of carbon and energy. Due to the complexity of mcl-PHAs’ metabolism, the manner in which P. putida changes its transcriptome to favor mcl-PHA synthesis in response to environmental stimuli remains unclear. Therefore, our objective was to investigate how the P. putida KT2440 wild type and mutants adjust their transcriptomes to synthesize mcl-PHAs in response to nitrogen limitation when supplied with sodium gluconate as an external carbon source. We found that, under nitrogen limitation, mcl-PHA accumulation is significantly lower in the mutant deficient in the stringent response than in the wild type or the rpoN mutant. Transcriptome analysis revealed that, under N-limiting conditions, 24 genes were downregulated and 21 were upregulated that were common to all three strains. Additionally, potential regulators of these genes were identified: the global anaerobic regulator (Anr, consisting of FnrA, Fnrb, and FnrC), NorR, NasT, the sigma54-dependent transcriptional regulator, and the dual component NtrB/NtrC regulator all appear to play important roles in transcriptome rearrangement under N-limiting conditions. The role of these regulators in mcl-PHA synthesis is discussed.

scholarly journals The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea Mays L.) in Southeastern Poland

2011 ◽  
Vol 51 (3) ◽  
pp. 210-216 ◽  
Author(s):  
Halina Kucharczyk ◽  
Paweł Bereś ◽  
Zbigniew Dąbrowski
Keyword(s):  
Zea Mays ◽  
Species Composition ◽  
Seasonal Dynamics ◽  
Food Source ◽  
Zea Mays L ◽  
Maize Plant ◽  
Seasonal Abundance ◽  
Immature Stages ◽  
Thrips Species

The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea MaysL.) in Southeastern PolandThrips species composition and seasonal abundance was studied on maize crops during two seasons (2006-2007), in southeastern Poland. Altogether 21 species have been identified, among themFrankliniella tenuicornis(Uzel 1895) andHaplothrips aculeatus(Fabricius 1803) which are a graminicolous species and were eudominants, comprising 96.8% in 2006 and 82.0% in 2007 of all collected specimens. Other species occurred only in low numbers. The frequent and numerous presence ofF. tenuicornisspecies in their immature stages in the samples, confirmed the role of the maize plant as the host.H. aculeatusprobably chose maize as a food source and substitute plant for breeding.

scholarly journals Cytosolic Phospholipase A2α–deficient Mice Are Resistant to Collagen-induced Arthritis

2003 ◽  
Vol 197 (10) ◽  
pp. 1297-1302 ◽  
Author(s):  
Martin Hegen ◽  
Linhong Sun ◽  
Naonori Uozumi ◽  
Kazuhiko Kume ◽  
Mary E. Goad ◽  
...  
Keyword(s):  
Critical Role ◽  
Wild Type ◽  
Collagen Induced Arthritis ◽  
Cytosolic Phospholipase ◽  
Severity Scores ◽  
In The Wild ◽  
Cytosolic Phospholipase A2α ◽  
Antibody Levels ◽  
Deficient Mice

Pathogenic mechanisms relevant to rheumatoid arthritis occur in the mouse model of collagen-induced arthritis (CIA). Cytosolic phospholipase A2α (cPLA2α) releases arachidonic acid from cell membranes to initiate the production of prostaglandins and leukotrienes. These inflammatory mediators have been implicated in the development of CIA. To test the hypothesis that cPLA2α plays a key role in the development of CIA, we backcrossed cPLA2α-deficient mice on the DBA/1LacJ background that is susceptible to CIA. The disease severity scores and the incidence of disease were markedly reduced in cPLA2α-deficient mice compared with wild-type littermates. At completion of the study, >90% of the wild-type mice had developed disease whereas none of the cPLA2α-deficient mice had more than one digit inflamed. Furthermore, visual disease scores correlated with severity of disease determined histologically. Pannus formation, articular fibrillation, and ankylosis were all dramatically reduced in the cPLA2α-deficient mice. Although the disease scores differed significantly between cPLA2α mutant and wild-type mice, anti-collagen antibody levels were similar in the wild-type mice and mutant littermates. These data demonstrate the critical role of cPLA2α in the pathogenesis of CIA.

scholarly journals The Role of Indigenous Mycorrhiza in Combination with Cattle Manure in Improving Maize Yield (Zea Mays L) on Sandy Loam of Northern Lombok, Eastern of Indonesia

2013 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
Wahyu Astiko ◽  
Ika Rochdjatun Sastrahidayat ◽  
Syamsuddin Djauhari ◽  
Anton Muhibuddin
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Sandy Loam ◽  
Maize Yield ◽  
Cattle Manure ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Inorganic Fertilizers ◽  
Organic C

A glass house study was conducted to evaluate the contribution of indigenous arbuscular mycorrhiza fungi (AMF) in improving maize yield grown on sandy loam of Northern Lombok. The package of organic fertilizers treatments were tested including: without inoculation of mycorrhiza, inoculation mycorrhiza and no added inorganic fertilizers, inoculation of mycorrhiza with cattle manure added, inoculation of mycorrhiza with rock phosphate added and inoculation mycorrhiza with inorganic fertilizers. The treatments were arranged using a Completely Randomized Design with four replications. The results of the study show that the inoculation of AMF significantly increased soil concentration of N, available-P, K and organic-C by 37.39%, 60.79%, 66.66% and 110.15% respectively observed at 60 days after sowing (DAS). The similar trend was also found at 100 DAS, where those nutrients increased by 21.48%, 69%, 43.93% and 37.07%, respectively compared to control. The improving of soil fertility status was also reflected by nutrients uptake (i.e. N, P, K, Ca) as well as growth and yield of maize. N, P, K and Ca uptake increased by 1,608%, 1,121%, 533% and 534%, respectively. Roots and top dry biomass at 60 DAS increased by 718.40% and 337.67%, respectively. The trend increased of the biomass was followed by observation at 100 DAS. Yield components including cobs, grain and weight of 100 grains increased by 313.60%, 411.84% and 137.54%, respectively. In addition, the inoculation of AM with F2 contributed significantly to the spore numbers and root infection.[How to Cite : Astiko W, IR Sastrahidayat, S Djauhari, and A Muhibuddin. 2013. The Role of Indigenous Mycorrhiza in Combination with Cattle Manure in Improving Maize Yield (Zea Mays L) on Sandy Loam of Northern Lombok, Eastern of Indonesia. J Trop Soils, 18 (1): 53-58. doi: 10.5400/jts.2013.18.1.53][Permalink/DOI: www.dx.doi.org/10.5400/jts.2013.18.1.53]

Muscle development is independent of innervation during Drosophila embryogenesis

Development ◽  
1993 ◽  
Vol 119 (2) ◽  
pp. 533-543 ◽  
Author(s):  
K. Broadie ◽  
M. Bate
Keyword(s):  
Time Course ◽  
Muscle Development ◽  
Single Cells ◽  
Drosophila Embryo ◽  
Wild Type ◽  
Type Pattern ◽  
Motor Nerves ◽  
Embryonic Myogenesis ◽  
Peripheral Motor

We have examined the role of innervation in directing embryonic myogenesis, using a mutant (prospero), which delays the pioneering of peripheral motor nerves of the Drosophila embryo. In the absence of motor nerves, myoblasts fuse normally to form syncytial myotubes, myotubes form normal attachments to the epidermis, and a larval musculature comparable to the wild-type pattern is generated and maintained. Likewise, the twist-expressing myoblasts that prefigure the adult musculature segregate normally in the absence of motor nerves, migrate to their final embryonic positions and continue to express twist until the end of embryonic development. In the absence of motor nerves, myotubes uncouple at the correct developmental stage to form single cells. Subsequently, uninnervated myotubes develop the mature electrical and contractile properties of larval muscles with a time course indistinguishable from normally innervated myotubes. We conclude that innervation plays no role in the patterning, morphogenesis, maintenance or physiological development of the somatic muscles in the Drosophila embryo.

A new class of mutations in Arabidopsis thaliana, acaulis1, affecting the development of both inflorescences and leaves

Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 751-764 ◽  
Author(s):  
H. Tsukaya ◽  
S. Naito ◽  
G. P. Redei ◽  
Y. Komeda
Keyword(s):  
Arabidopsis Thaliana ◽  
Apical Meristem ◽  
Developmental Stages ◽  
Temperature Shift ◽  
Wild Type ◽  
New Class ◽  
Group 4 ◽  
Consequent Reduction ◽  
In The Wild ◽  
Specific Temperature

We isolated and analyzed mutants of Arabidopsis thaliana, acaulis, with flower stalks that are almost absent or are much reduced in length. The mutations are divided between two loci, acaulis1 (acl1) and acaulis2 (acl2). The acl1-1 mutation has been assigned to linkage group 4 in the vicinity of locus ap2. The acl1-1 mutant showed premature arrest of the inflorescence meristem after the onset of reproductive development, followed by consequent reduction in the number of flower-bearing phytomers and therefore flowers. The apical meristem of the inflorescences was morphologically normal but its radius was about half that of the wild type. The acl1 mutants are also defective in the development of foliage leaves. Both defects could be rescued by growth at a specific temperature (28°C). The length of the cells in acl1-3 mutant was less than that in the wild type but the numbers of cells in leaves and internodes of acl1 mutants were calculated to be the same as those of the wild type. Thus, the defects in inflorescences and leaves were attributed to defects in the process of elongation (maturation) of these cells. Temperature-shift experiments showed that the Acl1+ product was necessary at all developmental stages. A critical stage was shown to exist for recovery from the cessation of development of inflorescence meristems that was caused by the acl1-1 mutation. Grafting experiments showed that the acl1-1 mutation does not affect diffusible substances. An analysis of double mutants carrying both acl1-1 and one of developmental mutations, ap1, clv1, lfy, or tfl1, showed that ACL1 is a new class of gene.

The development of the sensory neuron pattern in the antennal disc of wild-type and mutant (lz3, ssa) Drosophila melanogaster

Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 1063-1075
Author(s):  
M.C. Lienhard ◽  
R.F. Stocker
Keyword(s):  
Drosophila Melanogaster ◽  
Sensory Neuron ◽  
Antennal Segment ◽  
Wild Type ◽  
Homeotic Mutant ◽  
In The Wild ◽  
The Brain ◽  
Antennal Disc ◽  
Antennal Nerve

The development of the sensory neuron pattern in the antennal disc of Drosophila melanogaster was studied with a neuron-specific monoclonal antibody (22C10). In the wild type, the earliest neurons become visible 3 h after pupariation, much later than in other imaginal discs. They lie in the center of the disc and correspond to the neurons of the adult aristal sensillum. Their axons join the larval antennal nerve and seem to establish the first connection towards the brain. Later on, three clusters of neurons appear in the periphery of the disc. Two of them most likely give rise to the Johnston's organ in the second antennal segment. Neurons of the olfactory third antennal segment are formed only after eversion of the antennal disc (clusters t1-t3). The adult pattern of antennal neurons is established at about 27% of metamorphosis. In the mutant lozenge3 (lz3), which lacks basiconic antennal sensilla, cluster t3 fails to develop. This indicates that, in the wild type, a homogeneous group of basiconic sensilla is formed by cluster t3. The possible role of the lozenge gene in sensillar determination is discussed. The homeotic mutant spineless-aristapedia (ssa) transforms the arista into a leg-like tarsus. Unlike leg discs, neurons are missing in the larval antennal disc of ssa. However, the first neurons differentiate earlier than in normal antennal discs. Despite these changes, the pattern of afferents in the ectopic tarsus appears leg specific, whereas in the non-transformed antennal segments a normal antennal pattern is formed. This suggests that neither larval leg neurons nor early aristal neurons are essential for the outgrowth of subsequent afferents.

Pax6 regulates specification of ventral neurone subtypes in the hindbrain by establishing progenitor domains

Development ◽  
2002 ◽  
Vol 129 (6) ◽  
pp. 1327-1338 ◽  
Author(s):  
Masanori Takahashi ◽  
Noriko Osumi
Keyword(s):  
Expression Patterns ◽  
Domain Formation ◽  
Wild Type ◽  
Whole Embryo Culture ◽  
Neuronal Markers ◽  
Signalling Molecules ◽  
Neuronal Progenitors ◽  
In The Wild ◽  
Mutant Rat

Recent studies have shown that generation of different kinds of neurones is controlled by combinatorial actions of homeodomain (HD) proteins expressed in the neuronal progenitors. Pax6 is a HD protein that has previously been shown to be involved in the differentiation of the hindbrain somatic (SM) motoneurones and V1 interneurones in the hindbrain and/or spinal cord. To investigate in greater depth the role of Pax6 in generation of the ventral neurones, we first examined the expression patterns of HD protein genes and subtype-specific neuronal markers in the hindbrain of the Pax6 homozygous mutant rat. We found that Islet2 (SM neurone marker) and En1 (V1 interneurone marker) were transiently expressed in a small number of cells, indicating that Pax6 is not directly required for specification of these neurones. We also observed that domains of all other HD protein genes (Nkx2.2, Nkx6.1, Irx3, Dbx2 and Dbx1) were shifted and their boundaries became blurred. Thus, Pax6 is required for establishment of the progenitor domains of the ventral neurones. Next, we performed Pax6 overexpression experiments by electroporating rat embryos in whole embryo culture. Pax6 overexpression in the wild type decreased expression of Nkx2.2, but ectopically increased expression of Irx3, Dbx1 and Dbx2. Moreover, electroporation of Pax6 into the Pax6 mutant hindbrain rescued the development of Islet2-positive and En1-positive neurones. To know reasons for perturbed progenitor domain formation in Pax6 mutant, we examined expression patterns of Shh signalling molecules and states of cell death and cell proliferation. Shh was similarly expressed in the floor plate of the mutant hindbrain, while the expressions of Ptc1, Gli1 and Gli2 were altered only in the progenitor domains for the motoneurones. The position and number of TUNEL-positive cells were unchanged in the Pax6 mutant. Although the proportion of cells that were BrdU-positive slightly increased in the mutant, there was no relationship with specific progenitor domains. Taken together, we conclude that Pax6 regulates specification of the ventral neurone subtypes by establishing the correct progenitor domains.

scholarly journals A 13C-NMR study of the role of Asn-155 in stabilizing the oxyanion of a subtilisin tetrahedral adduct

1997 ◽  
Vol 326 (3) ◽  
pp. 861-866 ◽  
Author(s):  
Timothy P. O'CONNELL ◽  
Regina M. DAY ◽  
Ekaterina V. TORCHILIN ◽  
William W. BACHOVCHIN ◽  
J. Paul G. MALTHOUSE
Keyword(s):  
13C Nmr ◽  
Chemical Shifts ◽  
Catalytic Efficiency ◽  
Site Directed Mutagenesis ◽  
Wild Type ◽  
Imidazolium Cation ◽  
Nmr Study ◽  
In The Wild ◽  
Main Factor

By removing one of the hydrogen-bond donors in the oxyanion hole of subtilisin BPN, we have been able to determine how it affects the catalytic efficiency of the enzyme and the pKa of the oxyanion formed in a choloromethane inhibitor derivative. Variant 8397 of subtilisin BPN contains five mutations which enhance its stability. Site-directed mutagenesis was used to prepare the N155A mutant of this variant. The catalytic efficiencies of wild-type and variant 8397 are similar, but replacing Asn-155 with alanine reduces catalytic efficiency approx. 300-fold. All three forms of subtilisin were alkylated using benzyloxycarbonylglycylglycyl[2-13C]phenylalanylchloromethane and examined by 13C-NMR. A single signal due to the 13C-enriched carbon was detected in all the derivatives and it was assigned to the hemiketal carbon of a tetrahedral adduct formed between the hydroxy group of Ser-221 and the inhibitor. This signal had chemical shifts in the range 98.3–103.6 p.p.m., depending on the pH. The titration shift of 4.7–4.8 p.p.m. was assigned to oxyanion formation. The oxyanion pKa values in the wild-type and 8397 variants were 6.92 and 7.00 respectively. In the N155A mutant of the 8397 variant the oxyanion pKa increased to 8.09. We explain why such a small increase is observed and we conclude that it is the interaction between the oxyanion and the imidazolium cation of the active-site histidine that is the main factor responsible for lowering the oxyanion pKa.

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