| evidence for cytoplasmic control of in vitro microspore embryogenesis in the anther culture of wheat (triticum aestivum l.). | anthers were cultured from two sets of seven lines of hexaploid wheat (triticum aestivum l.) with different cytoplasms, the euplasmic nucleus donors, 'siete cerros 66' and 'penjamo 62', as well as their six alloplasmic lines derived from wild relative species of the genera triticum and aegilops. significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of 'penjamo 62' in ae. kotschyi cytoplasm. plant r ... | 1989 | 24226021 |
| control of tissue culture response in wheat (triticum aestivum l.). | the ability of immature embryos of wheat (triticum aestivum l.) to respond to tissue culture has been shown to involve the group 2 chromosomes. the available group 2 ditelosomic and nullisomic-tetrasomic lines of 'chinese spring' wheat were used to determine the chromosome arm location and chromosome dosage effect associated with the expression of tissue culture response (tcr). significant differences were found between the aneuploid lines and the euploid control for the expression of both regen ... | 1989 | 24226006 |
| control of water and nutrients using a porous tube: a method for growing plants in space. | a plant nutrient delivery system that uses a microporous, hydrophilic tube was developed with potential application for crop production in the microgravity of space. the tube contains a nutrient solution and delivers it to the roots. pumps attached to the tubing create a very small suction that holds the solution within the tube. this system was used to grow wheat (triticum aestivum cv. yecora rojo) for 107 days in a controlled environment at suctions of 0.40, 1.48, or 2.58 kpa. the water absorb ... | 1989 | 11540906 |
| extent of genetic variability of endosperm esterases in triticum aestivum l. 2n=6x=42. | genetic variability of endosperm esterase has been studied in 42 cultivars of triticum aestivum l. 2n=6x=42. different techniques, including sequential electrophoresis and electrofocusing, have been used with various substrates and esterase inhibitors. the electrophoretic patterns in each cultivar are described. chromosomal location using the nullitetrasomic and ditelosomic lines of chinese spring was carried out in order to relate and/or locate the esterase genes to specific chromosomes. most o ... | 1989 | 24225835 |
| monosomic analysis of tissue culture response in wheat (triticum aestivum l.). | the ability of immature embryos of wheat (triticum aestivum l.) to respond in cell culture was examined in crosses between the 'wichita' monosomic series and a highly regenerable line, 'nd7532'. segregation in disomic controls and 13 monosomic families showed a good fit to a monogenic ratio indicating a qualitative mode of inheritance. segregation in the cross involving monosomic 2d showed a high frequency of regeneration (93.6%) and high callus growth rate (1.87 g/90 days) indicating that 2d is ... | 1989 | 24225821 |
| action spectrum for the effect of day-extensions on flowering and apex elongation in green, light-grown wheat (triticum aestivum l.). | fluence-rate response curves for wavelengths from 640 nm to 730 nm were constructed for the day-extension promotion of flowering in green, light-grown, wheat (triticum aestivum l., cv. alexandria), a long-day plant. the resultant action spectrum had action maxima at 660 nm and 716 nm and resembles spectra for the high-irradiance reaction (hir) seen in etiolated plants. because, the hir is thought to be controlled by type i pytochrome (that which is most abundant in etiolated tissue) our results ... | 1989 | 24201765 |
| mechanisms of aluminum tolerance in wheat : an investigation of genotypic differences in rhizosphere ph, k, and h transport, and root-cell membrane potentials. | control of rhizosphere ph and exclusion of al by the plasma membrane have been hypothesized as possible mechanisms for al tolerance. to test primarily the rhizosphere ph hypothesis, wheat cultivars (triticum aestivum l. ;atlas 66' and ;scout'), which differ in al tolerance, were grown in either complete nutrient solution, or 0.6 millimolar caso(4), with and without al at ph 4.50. a microelectrode system was used to simultaneously measure rhizosphere ph, k(+), and h(+) fluxes, and membrane potent ... | 1989 | 16667131 |
| kinetics of aluminum uptake by excised roots of aluminum-tolerant and aluminum-sensitive cultivars of triticum aestivum l. | uptake of aluminum (al) by excised roots of two al-tolerant cultivars and two al-sensitive cultivars of triticum aestivum l. (wheat) was biphasic, with a rapid phase of uptake in the first 30 minutes followed by a linear phase of uptake up to 180 minutes. at the end of the uptake period, higher concentrations of al were found in roots of the al-sensitive cultivars (neepawa and scout-66) than in the al-tolerant cultivars (atlas-66 and pt-741), but differences were small. experiments testing the e ... | 1989 | 16667117 |
| evidence that the adverse effect of urea fertilizer on seed germination in soil is due to ammonia formed through hydrolysis of urea by soil urease. | studies using seeds of wheat (triticum aestivum l.), rye (secale cereale l.), barley (hordeum vulgare l.), and corn (zea mays l.) indicated that the adverse effect of urea fertilizer on seed germination in soil is due to ammonia formed through hydrolysis of urea by soil urease and is not due to urea itself, to urea fertilizer impurities such as biuret, or to nitrite formed by nitrification of urea nitrogen. support for this conclusion was obtained from (i) comparison of the effects on seed germi ... | 1989 | 16594076 |
| conformational differences between two wheat (triticum aestivum) 'high-molecular-weight' glutenin subunits are due to a short region containing six amino acid differences. | 'high-molecular-weight' (hmw, high-mr) glutenin subunits are protein constituents of wheat (triticum aestivum) seeds and are responsible in part for the viscoelasticity of the dough used to make bread. two subunits, numbered 10 and 12, are the products of allelic genes. their amino acid sequences have been derived from the nucleic acid sequences of the respective genes. subunit 10 has fewer amino acids than subunit 12, but migrates more slowly on sds/page (polyacrylamide-gel electrophoresis). th ... | 1989 | 2597130 |
| effects of auxin and cytokinin on induction of sister chromatid exchanges in cultured cells of wheat (triticum aestivum l.). | in order to know the mutagenic effects of synthetic auxins (naa, 2,4-d, and 2,4,5-t) and a cytokinin (kinetin) in vitro, sister chromatid exchanges (sces) were analyzed in cultured cells of a hexaploid wheat (triticum aestivum l.). in the ms medium supplemented with 2.0 mg/l 2,4-d, the mean number of sces per cell was 15.2, and per pg of dna, 0.42. no significant effect was found in the treatments of naa or 2,4-d at concentrations of 0.5-10.0 mg/l, whereas more than 2.0 mg/l of 2,4,5-t induced d ... | 1989 | 24225679 |
| production and cytogenetics of hybrids of triticum aestivum x leymus innovatus. | hybrid plants were obtained between triticum aestivum (2n=6x=42, aabbdd) and leymus innovatus (2n=4x=28, jjnn) at a frequency varying from 0.4% to 1.2% of the pollinated florets. improvement of the embryo culture medium resulted in a higher frequency of embryo rescue. eight of ten hybrids had the expected chromosome number of 35 (abdjn). meiotic analysis indicated that there was no homology between the genomes of the two species. two hybrids had only 28 chromosomes. comparison of chromosome pair ... | 1989 | 24227254 |
| genetic and environmental considerations for evaluating crown position of wheat. | crown position affects winter survival of fallsown wheat (triticum aestivum l.) direct or indirect selection for crown depth has been little practiced. reports have suggested that short subcrown internode length was closely related to semidwarf plant height and that semidwarfism was related to poor emergence. this study determined the relationships among crown depth, plant height, and emergence rate index in three wheat populations. the efficiency of evaluating crown placement in the field was e ... | 1989 | 24227242 |
| calcium-dependent induction of novel proteins by abscisic acid in wheat aleurone tissue of different developmental stages. | aleurone tissue of mature wheat (triticum aestivum l. cv. sappo) grains make novel polypeptides in response to abscisic acid (aba), but only in the presence of ca(2+). effects of aba plus ca(2+) include up- and down-modulation of other polypeptides. the aba-induced polypeptides appear not to be the 21-kilodalton (kda) amylase inhibitor which has been reported to be aba-inducible in barley.aleurone tissue from developing grains of different ages failed to respond to aba plus ca(2+) in any way. en ... | 1989 | 24201514 |
| properties of pyrophosphate:fructose-6-phosphate phosphotransferase from endosperm of developing wheat (triticum aestivum l.) grains. | pyrophosphate:fructose-6-phosphate phosphotransferase (pfp, ec 2.7.1.90) from endosperm of developing wheat (triticum aestivum l.) grains was purified to apparent homogeneity with about 52% recovery using ammonium sulfate fractionation, ion exchange chromatography on deae-cellulose and gel filtration through sepharose-cl-6b. the purified enzyme, having a molecular weight of about 170,000, was a dimer with subunit molecular weights of 90,000 and 80,000, respectively. the enzyme exhibited maximum ... | 1989 | 16667036 |
| analysis of aluminum and divalent cation binding to wheat root plasma membrane proteins using terbium phosphorescence. | a phosphorescent trivalent cation, terbium [tb(iii)], has been used to study the binding of different polyvalent cations to the proteins of wheat (triticum aestivum l.) root plasma membranes. the phosphorescence emission intensity of tb(iii) was enhanced after tb(iii) binding to wheat root plasma membranes as a result of nonradiative resonance energy transfer from the membrane protein tyrosine and phenylalanine residues. complex, saturable tb(iii) binding was observed, suggesting multiple bindin ... | 1989 | 16667003 |
| rate of accumulation of fructan oligomers in wheat seedlings (triticum aestivum l.) during the early stages of chilling treatment. | the accumulation of soluble carbohydrates was studied during chilling of 2-week-old wheat (triticum aestivum l.) seedlings. the extracts were analysed using a c18 hplc method separating hexoses, sucrose and a wide range of oligofructan. isomers were recognized and their content determined. the amounts of hexoses, sucrose and the trisaccharides 1-kestose and 6-kestose increased at the beginning of the treatment. the accumulation rate of 1-kestose, the trisaccharide generally considered to be the ... | 1989 | 29265429 |
| cytokinin oxidase from wheat: partial purification and general properties. | as part of the study of the possible role(s) of cbf-1, a cytokinin-binding protein abundant in wheat embryo, a cytokinin oxidase was found in wheat (triticum aestivum l.) germ and partially purified by conventional purification techniques and high performance chromatofocusing. this preparation catalyzes conversion of n(6)-(delta(2)-isopentenyl)adenosine to adenosine at a v(max) of 0.4 nanomol per milligram protein per minute at 30 degrees c and ph 7.5, the k(m) being 0.3 micromolar. this high af ... | 1989 | 16666895 |
| recombination of r-d chromosome in pollen plants cultured from hybrid of 6x triticale x common wheat. | ninety-three pollen plants derived from the hybrid f1 of 6x triticale x common wheat were observed cytologically. the rye chromosomes presented in these plants were identified by giemsa-banding. pollen plants having chromosome constitution 2n = 24 in haploids and 2n=46 in diploids were found to be predominant. the chromosome distributions of the r and d genome are different. r chromosomes distributed randomly and tended to full combination in offspring, but d chromosomes distributed non-randomly ... | 1989 | 24232910 |
| analysis of phylogenetic relations of durum, carthlicum and common wheats by means of comparison of alleles of gliadin-coding loci. | polymorphism and inheritance of wheat storage protein, gliadin, of durum (macaroni) and carthlicum wheats have been studied. analysis of gliadin in 78 cultivars and in f2 seeds of intercultivar crosses of durum wheat revealed three different chromosome 1a-encoded blocks of components similar to those found in common wheat (gld1a2, gld1a18, gld1a19). most of the durum cultivars studied had these three blocks; gld1a2 was also frequent in common wheat. in contrast, all chromosome 1b-encoded blocks ... | 1989 | 24232907 |
| activation of higher plant phosphoenolpyruvate carboxylases by glucose-6-phosphate. | studies of the response of phosphoenolpyruvate carboxylase from c(3) (wheat [triticum aestivum l.]), c(4) (maize [zea mays l.]), and crassulacean acid metabolism (cam) (crassula) leaves to the activator glucose-6-phosphate as a function of ph showed that the binding of the activator and the response path to activation were essentially identical for all three enzymes. the level of affinity for the activator differed, with the cam enzyme having the highest affinity and the maize enzyme the lowest. ... | 1989 | 16666822 |
| seed dormancy and responses of caryopses, embryos, and calli to abscisic acid in wheat. | preharvest sprouting of wheat (triticum aestivum l.) is associated with inadequate seed dormancy. although abscisic acid (aba) has often been suggested to play a central role in developing seed, its involvement in dormancy of mature seed lacks firm experimental evidence and endogenous aba levels are not well correlated with germinability. we examined genotypic and temporal variation in wheat seed and embryo germination responses to aba and determined whether differential sensitivity of embryos t ... | 1989 | 16666821 |
| heat shock response of germinating embryos of wheat : effects of imbibition time and seed vigor. | seeds frequently face a hostile environment during early germination. in order to determine whether seeds have evolved unique mechanisms to deal with such environments, a survey of the heat shock response in isolated embryos of wheat (triticum aestivum l.) was undertaken. embryos simultaneously heat shocked and labeled following several different periods of prior imbibition up to 12 hours synthesized many groups of heat shock proteins (hsps) typical of other plant and animal systems. also, five ... | 1989 | 16666814 |
| photorespiratory rates in wheat and maize as determined by o-labeling. | a method was devised to quantify short-term photorespiratory rates in terrestrial plants using (18)o-intermediates of the glycolate pathway, specifically glycolate, glycine, and serine. the pathway intermediates were isolated and analyzed on a gc/ms to determine molecular percent (18)o-enrichment. rates of glycolate synthesis were determined from (18)o-labeling kinetics of the intermediates, derived rate equations, and nonlinear regression techniques. glycolate synthesis in wheat (triticum aesti ... | 1989 | 16666799 |
| molecular analysis of an alcohol dehydrogenase (adh) gene from chromosome 1 of wheat. | we have cloned and determined the nucleotide sequence of a gene encoding alcohol dehydrogenase (adh) from triticum aestivum cv. millewa. southern analysis using cv. chinese spring nullisomic-tetrasomic and ditelosomic lines established that the cloned gene mapped to the long arm of chromosome 1a and does not correspond to any previously identified wheat adh locus. southern analysis also provided evidence for triplicate copies of this adh gene on the homoeologous group 1 chromosomes, while northe ... | 1989 | 2545522 |
| efficient production of haploid wheat (triticum aestivum) through crosses between japanese wheat and maize (zea mays). | four japanese wheat varieties, three crossable and one non-crossable with hordeum bulbosum, were pollinated with maize pollen of 5 genotypes. by the application of 2,4-dichlorophenoxyacetic acid after pollination, embryos kept developing on wheat plants until 14 days after pollination. the frequency of embryo formation was significantly different among the maize genotypes, varying from 18.0% to 31.9%, but not among the wheat varieties. by bagging spikes with flag leaves the frequency of embryo f ... | 1989 | 24233221 |
| the characterization and comparative analysis of high-molecular-weight glutenin genes from genomes a and b of a hexaploid bread wheat. | two high-molecular-weight subunit (hmws) glutenin genes from the a and b genomes of the hexaploid bread wheat triticum aestivum l. cv cheyenne have been isolated and sequenced. both of these genes are of the high mr class (x-type) of hmw glutenins, and have not been previously reported. the entire set of six hmw genes from cultivar cheyenne have now been isolated and characterized. an analysis of the ax and bx sequences shows that the ax sequence is similar to the homoeologous gene from the d ge ... | 1989 | 24232803 |
| comparative performance of bread wheat and hexaploid triticale cytoplasms. | thirteen wheat-like advanced-generation triticale x wheat derivatives, having tetraploid wheat cytoplasm from triticale, were reciprocally crossed with three improved bread wheats, and the resulting f1s were evaluated for determining the comparative performance of the bread wheat and triticale cytoplasms for different traits. significant reciprocal differences in the mean performance were observed for days to heading, days to maturity, spikes/plant, flag-leaf area, peduncle length, plant height, ... | 1989 | 24232802 |
| sulphate influx in wheat and barley roots becomes more sensitive to specific protein-binding reagents when plants are sulphate-deficient. | when young wheat (triticum aestivum l.) or barley (hordeum vulgare l.) plants were deprived of an external sulphate supply (-s plants), the capacity of their roots to absorb sulphate, but not phosphate or potassium, increased rapidly (derepression) so that after 3-5 d it was more than tenfold that of sulphate-sufficient plants (+s plants). this increased capacity was lost rapidly (repression) over a 24-h period when the sulphate supply was restored. there was little effect on the uptake of l-met ... | 1989 | 24212755 |
| heat shock protein synthesis and thermal tolerance in wheat. | plants respond to high temperature stress by the synthesis of an assortment of heat shock proteins that have been correlated with an acquired thermal tolerance to otherwise lethal temperatures. this study was conducted to determine whether genotypic differences in acquired thermal tolerance were associated with changes in the pattern of heat shock protein synthesis. the pattern of heat shock protein synthesis was analyzed by (35)s-methionine incorporation in wheat (triticum aestivum l.) varietie ... | 1989 | 16666724 |
| wheat tetrameric inhibitors of insect alpha-amylases: alloploid heterosis at the molecular level. | tetrameric inhibitors of heterologous alpha-amylases have been characterized in allohexaploid wheat, triticum aestivum (genomes aabbdd), as well as in triticum turgidum (aabb) and triticum tauschii (dd). their subunits have been identified as the previously described cm proteins. single oligomeric species were observed in t. turgidum (subunits cm2, cm3a, and cm16) and in t. tauschii (cm1, cm3d, and cm17) by a two-dimensional electrophoretic method that does not dissociate the inhibitors in the f ... | 1989 | 16594035 |
| single-strand-preferring nuclease activity in wheat leaves is increased in senescence and is negatively photoregulated. | single-strand-preferring nucleases (ec 3.1.30.1) selectively cleave internucleotide bonds in single-stranded regions of predominantly duplex dna and dna.rna hybrids and extensively degrade denatured dna and rna. the functions of single-strand-preferring nuclease in plants are unknown. we have monitored this nuclease activity in flag leaves of wheat (triticum aestivum l. cv. chinese spring) undergoing natural senescence and in primary leaves of wheat seedlings undergoing dark-induced senescence. ... | 1989 | 16594032 |
| a nuclear trna(ugaser) gene from the wheat triticum vulgare var. aria. | the nucleotide sequence of a wheat nuclear trna(ugaser) gene from triticum vulgare var. aria has been determined. it has a typical intragenic promoter with boxa and boxb elements and a putative termination signal 12 nucleotides downstream from the last trna-coding nucleotide. the region upstream from the coding segment contains a g + c-rich sequence with a symmetrical element. the sequence described is the first nuclear trna gene from a monocotyledonous plant. | 1989 | 2744486 |
| arabinoxylans from rye and wheat seed that interact with ice. | arabinoxylans that interfere with growth of ice crystals have been purified from rye (secale cereale l., rosen) and two varieties of wheat (triticum aestivum l., genesee and hillsdale) seed. the most active polysaccharide from each seed type was homogeneous in the sense that all the molecules were in the same size range, they contained the same sugar residues, and they reacted similarly in chemical characterization experiments. structural studies showed that the polysaccharides consist of a xyla ... | 1989 | 2743349 |
| maintenance of photosynthesis at low leaf water potential in wheat : role of potassium status and irrigation history. | the interaction of low water potential effects on photosynthesis, and leaf k(+) levels in wheat (triticum aestivum l.) plants was studied. plants were grown at three k(+) fertilization levels; 0.2, 2, and 6 millimolar. with well watered plants, 2 millimolar k(+) supported maximal photosynthetic rates; 0.2 millimolar k(+) was inhibitory, and 6 millimolar k(+) was superoptimal (i.e. rates were no greater than at 2 millimolar k(+)). photosynthesis was monitored at high (930 parts per million) and l ... | 1989 | 16666710 |
| chimeric gene expression using maize intron in cultured cells of breadwheat. | high voltage electrical pulses were used to introduce the cat reporter gene into cultured protoplasts of breadwheat,triticum aestivum. four dna constructs harboring the cat gene and the 35s or mannipine synthase promoter were tested for levels of cat activity 40-45 hr after electroporation of protoplasts. one construct, containing a maize intron sequence between 35s and cat sequences, conferred 30 to 185 fold greater cat activity over the other three constructs. data from these experiments sugge ... | 1989 | 24233093 |
| phytotoxicity of water-soluble substances from alfalfa and barley soil extracts on four crop species. | problems associated with continuously planting alfalfa (medicago saliva l.) or seeding to thicken depleted alfalfa stands may be due to autotoxicity, an intraspecific form of allelopathy. a bioassay approach was utilized to characterize the specificity and chemical nature of phytotoxins in extracts of alfalfa soils as compared to fallow soil or soil where a cereal was the previous crop. in germination chamber experiments, water-soluble substances present in methanol extracts of soil cropped to a ... | 1989 | 24271803 |
| production and cytogenetics of triticum aestivum l. hybrids with some rhizomatous agropyron species. | intergeneric hybrids between triticum aestivum l. and conventional rhizomatous agropyron species were produced in variable frequencies. they were recovered in high percentage frequencies for t. aestivum cultivars with a. acutum (14.6%), a. intermedium (48.0%), a. pulcherrimum (53.3%), and a. trichophorum (46.6%). the crossability percentages with the highly crossable cultivar 'chinese spring' for these agropyron species accessions were 33.12%, 65.0%, 53.3%, and 65.4%, respectively. autosyndetic ... | 1989 | 24232523 |
| main stem sink manipulation in wheat : effects on nitrogen allocation to tillers. | the role of main stem (ms) sink size on n use by field-grown soft red winter wheat (triticum aestivum l. cv hart) was determined. at feeke's growth stage 8 (last leaf just visible), 100 micromoles of 99 atom% (15)n-ammonium was injected into the lower ms. at anthesis, ms sink size was adjusted by removal of 0, 33, 66, and 100% of the ms spikelets; tiller spikes were left intact. the ms and tiller average kernel size was unaffected by ms sink manipulations. the ms kernel n concentration increased ... | 1989 | 16666588 |
| synthesis of freezing tolerance proteins in leaves, crown, and roots during cold acclimation of wheat. | protein synthesis was studied in leaves, crown, and roots during cold hardening of freezing tolerant winter wheat (triticum aestivum l. cv fredrick and cv norstar) and freezing sensitive spring wheat (t. aestivum l. cv glenlea). the steady state and newly synthesized proteins, labeled with [(35)s]methionine, were resolved by one- and two-dimensional polyacrylamide gels. the results showed that cold hardening induced important changes in the soluble protein patterns depending upon the tissue and ... | 1989 | 16666585 |
| thermotolerance is developmentally dependent in germinating wheat seed. | during the initial 9 to 12 hours of imbibition, the imbibing wheat (triticum aestivum l.) seed was found to exhibit substantial tolerance to high temperature relative to later times of imbibition. tolerance was assessed by seed viability and seedling growth. this initial high temperature tolerance gradually declines with increasing time of seed imbibition. a range of 2 hour heat pretreatments (38-42 degrees c) prior to imposition of a 2 hour heat shock (51-53 degrees c) during this same 9 to 12 ... | 1989 | 16666584 |
| potential phytotoxicity associated with the use of soil urease inhibitors. | recent work in our laboratory showed that the adverse effect of urea fertilizer on seed germination and seedling growth in soil is due to ammonia produced through hydrolysis of urea by soil urease (nh(2)conh(2) + h(2)o --> 2nh(3) + co(2)) and can be eliminated by amending the fertilizer with a small amount of a urease inhibitor such as n-(n-butyl)thiophosphoric triamide or phenylphosphorodiamidate. continuation of this work showed that these inhibitors can induce leaf-tip necrosis in plants. res ... | 1989 | 16594016 |
| nucleotide sequences of the two high-molecular-weight glutenin genes from the d-genome of a hexaploid bread wheat, triticum aestivum l. cv cheyenne. | | 1989 | 2563152 |
| identification of a 1b/1r wheat-rye chromosome translocation. | the common wheat selection '79-4045' was identified as a wheat-rye 1b/1r chromosome translocation line, by means of c-banding patterns and test cross with 'chinese spring' double-ditelosomic line. the translocation chromosome consisted of the long arm of wheat chromosome 1b, including its centromere, and the short arm of rye chromosome 1r or tis portion. | 1989 | 24232478 |
| the cumulative effect of allelic variation in lmw and hmw glutenin subunits on dough properties in the progeny of two bread wheats. | the effects of allelic variation at gli-a1, glua3 and glu-a1 loci coding for gliadins, lmw glutenin subunits and hmw glutenin subunits on dough resistance and extensibility was analysed in 56 f2-derived f6 families from a cross between bread wheats mkr(111/8) and 'kite'. extensograph data from two sites giving widely different flour protein levels (approximately 7% and 14%) revealed that the glu-a3m and glu-a1b alleles were associated with larger effects on dough resistance and extensibility tha ... | 1989 | 24232474 |
| chloroplast thylakoid protein phosphatase is a membrane surface-associated activity. | chloroplast thylakoid protein phosphatase activity was measured using (32)p-labeled histone as an exogenous substrate and an assay of the (32)pi released involving formation of a phosphomolybdate complex and organic extraction. the activity was liberated from wheat (triticum aestivum) thylakoids by washing the membranes in nacl-containing solutions followed by centrifugation. the liberated phosphatase activity had a ph optimum of approximately 6.75, was inhibited by addition of 10 millimolar edt ... | 1989 | 16666520 |
| effects of ozone on the yield of spring wheat (triticum aestivum l., cv. albis) grown in open-top field chambers. | spring wheat (triticum aestivum l., cv. albis) was grown in the field at a site located in central switzerland, and exposed to chronic doses of ozone (o(3)) in open-top chambers to study impacts on yield. the experiment was carried out in 1986, 1987 and 1988. the treatments used included charcoal-filtered air (cf), non-filtered air (nf) and non-filtered air to which constant amounts of o(3) (two levels, o(3)-1 and o(3)-2) were added daily from 09.00 until 17.00 local time. mean solar radiation-w ... | 1989 | 15092381 |
| effect of co2 and o2 on development and fructification of wheat in closed systems. | the cultivation of wheat (triticum aestivum l.) was performed in controlled environment chambers with the continuous monitoring of photosynthesis, dark respiration, transpiration and main nutrient uptakes. a protocol in twin chambers was developed to compare the specific effects of low o2 and high co2. each parameter is able to influence photosynthesis but different effects are obtained in the development, fructification and seed production, because of the different effects of each parameter on ... | 1989 | 11537385 |
| chromosomal location by f1 monosomic analysis of endosperm proteins in bread wheat : 2. two-dimensional fractionation of gliadins. | the gliadin components from four bread wheat cultivars: chinese spring, capelle desprez, holdfast and pane-247 and their monosomic f1s for the chromosomes of homoeologous groups 1 and 6 have been analyzed by two-dimensional (2-ph) polyacrylamide gel electrophoresis. chromosomal location of gliadin genes and the allelic differences were well established by analyzing the different f1 monosomic hybrids, electrophoretical patterns and differences in relative staining intensity. a new gliadin encoded ... | 1988 | 24232407 |
| wheat-germ agglutinin is synthesized as a glycosylated precursor. | the biosynthesis and processing of wheat-germ agglutinin (wga) were studied in developing wheat (triticum aestivum l. cv. marshall) embryos using pulse-chase labeling, subcellular fractionation and immunocytochemistry. a substantial amount of newly synthesized wga was organelle-associated. isolation of wga on affinity columns of immobilized n-acetylglucosamine indicated that it was present in a dimeric form. when extracts from embryos pulse-labeled with [(35)s]cysteine were fractionated on an is ... | 1988 | 24226685 |
| cell-type-specific expression of a wheat-germ agglutinin gene in embryos and young seedlings of triticum aestivum. | we have investigated the levels of cell-specific expression of wheat-germ agglutinin (wga) during the development of embryos and in 3-d-old seedlings. southern blot analysis of genomic dna derived from hexaploid and diploid wheat (triticum) species indicates that the isolated cdna (complementary dna) clone is specific for isolectin b (wga-b). specific accumulation of transcript for wga-b was determined by rna blot analysis and in-situ hybridization. the wga-b mrna increased tenfold during embryo ... | 1988 | 24220870 |
| control of wheat root growth. the effects of excision on growth, wall rheology and root anatomy. | excision and subsequent incubation of the apices (1 cm) of wheat (triticum aestivum l.) seedling roots in simple media severely reduced elongation from 28 mm·(24 h)(-1) in intact roots to a maximum of 2 mm·(24 h)(-1) in excised roots. the reduction in growth was accompanied by a loss of cell turgor in the growing zone but was correlated with a hardening of the cell walls in this region. rheological properties were measured as percent extensibility (both plastic and elastic) using a tensiometer, ... | 1988 | 24220869 |
| genomic instability in wheat induced by chromosome 6b(s) of triticum speltoides. | a massive restructuring of chromosomes was observed during the production of a substitution of chromosome 6b(s) from triticum speltoides (tausch) gren. ex richter for chromosome 6b of chinese spring wheat (triticum aestivum l.). deletions, translocations, ring chromosomes, dicentric chromosomes and a paracentric inversion were observed. chromosome rearrangements occurred in both euchromatic and heterochromatic regions. chromosome rearrangements were not observed either in the amphiploid between ... | 1988 | 17246485 |
| root formation in deteriorated (aged) wheat embryos. | inability of aged seeds to grow into successful plants in the field is primarily due to their age-associated loss of rooting ability. the present work describes an attempt to initiate roots in nonrooting aged embryos of wheat (triticum aestivum l.). data presented give a comparative study of root formation and seedling growth on different culture media. such studies indicate that sucrose alone is enough to bring about root development in nonrooting aged embryos. | 1988 | 16666491 |
| kinetic studies of the form of substrate bound by phosphoenolpyruvate carboxylase. | phosphoenolpyruvate carboxylase isolated from maize (zea mays l.) leaves was assayed with varying concentrations of free phosphoenolpyruvate at several fixed-varying concentrations of free magnesium higher than required to saturate the enzyme reaction. these assays produced velocity data which were found to form a family of individual lines when plotted against free phosphoenolpyruvate or against total phosphoenolpyruvate, but not when plotted against the concentration of the complex of phosphoe ... | 1988 | 16666489 |
| isolation of viable wheat male gametophytes of different stages of development and variations in their protein patterns. | procedures have been designed to isolate viable immature male gametophytes from wheat (triticum aestivum l.) anthers of different stages of development. maceration of anthers by a micro-blender allowed for the release of numerous intact vacuolate microspores. tris-buffered media prevented tricellular pollen grains from bursting during the isolation procedure. proteins from the undamaged male gametophytes have been analyzed by isoelectric focusing and sodium dodecyl sulfate-polyacryl-amide gel el ... | 1988 | 16666487 |
| the regulation of photosynthesis in leaves of field-grown spring wheat (triticum aestivum l., cv albis) at different levels of ozone in ambient air. | wheat (triticum aestivum l. cv albis) was grown in open-top chambers in the field and fumigated daily with charcoal-filtered air (0.015 microliters per liter o(3)), nonfiltered air (0.03 microliters per liter o(3)), and air enriched with either 0.07 or 0.10 microliters per liter ozone (seasonal 8 hour/day [9 am-5 pm] mean ozone concentration from june 1 until july 10, 1987). photosynthetic (14)co(2) uptake was measured in situ. net photosynthesis, dark respiration, and co(2) compensation concent ... | 1988 | 16666430 |
| polymorphism and inheritance of gliadin components controlled by chromosome 6a of spring durum wheat. | the gliadin composition of 78 spring durum wheat varieties has been studied by one-dimensional (al-lactate, ph 3.1) and two-dimensional (first dimension, al-lactate, ph 3.1; second dimension, sodium dodecyl sulfate-polyacrylamide gel) electrophoresis. analysis of hybrids has shown that all components of the alpha zone of gliadin spectra are inherited together as blocks and are, probably, coded for by a cluster of tightly linked genes located on chromosome 6a. fourteen variants of gliadin blocks ... | 1988 | 3242490 |
| chromosomal location by f1 monosomic analysis of endosperm proteins in bread wheat : 1. one-dimensional electrophoresis of glutenins and gliadins. | a new methodology to determine the chromosomal location and allelic differences of endosperm proteins in common wheat cultivars by analysis of monosomic intervarietal hybrids is reported. endosperm proteins from the common wheats chinese spring, capelle desprez, holdfast and pane 247 are studied using monosomic f1 for the chromosomes of homoeologous groups 1 and 6. the proteins were fractionated by two electrophoretical techniques, sds- and a-page. the use of monosomic offers a remarkable advant ... | 1988 | 24232358 |
| abscisic acid is not the only stomatal inhibitor in the transpiration stream of wheat plants. | xylem sap was collected from the transpiration stream of wheat (triticum aestivum l.) plants and assayed for the presence of an inhibitor of transpiration using leaves detached from well-watered plants. transpiration of detached leaves was reduced by nearly 60% by sap collected from plants in drying soil, and to a lesser extent (about 25%) by sap from plants in well-watered soil. as the soil dried the abscisic acid (aba) concentration in the sap increased by about 50 times to 5 x 10(-8) molar. h ... | 1988 | 16666371 |
| wheat protoplast culture: embryogenic colony formation from protoplasts. | wheat (triticum aestivum l. cv chinese spring) protoplasts were isolated from immature embryos or embryogenic calli (3-4 weeks of culture on ms medium with 32 mg/1 dicamba) and cultured in r2 medium containing 2 mg/1 2,4-d by the nurse culture methods originally developed for rice protoplasts (kyozuka et al. 1987). protoplasts isolated from embryogenic calli started to divide within 3-5 days and formed colonies at frequencies up to 2% after 3-4 weeks of culture, while protoplasts isolated from i ... | 1988 | 24240258 |
| identification of a kinase in wheat germ that phosphorylates the large subunit of initiation factor 4f. | a kinase has been isolated from wheat (triticum aestivum) germ that phosphorylates the 220 kilodaltons (kd) subunit of wheat germ initiation factor (eif) 4f, the 80 kd subunit of eif-4b (an isozyme form of eif-4f) and eif-4g (the functional equivalent to mammalian eif-4b). the kinase elutes from sephacryl s-200 slightly in front of ovalbumin. the kinase phosphorylates casein and histone iia to a small extent, but does not phosphorylate phosvitin. of the wheat germ initiation factors, elongation ... | 1988 | 16666331 |
| bicarbonate inhibits ribulose-1,5-bisphosphate carboxylase. | ribulose-1,5-bisphosphate carboxylase/oxygenase (rubpco) rapidly extracted from leaves of wheat (triticum aestivum) and purified activated rubpco were incubated in the presence and absence of 20 millimolar hco(3) (-) and changes in activation state were followed. rapid inactivation occurred in the presence, but not in the absence, of hco(3) (-). effects of co(2) concentration and ph during preincubation before assay on activation state of rubpco were investigated in equilibrium studies. twenty p ... | 1988 | 16666327 |
| identification of l-tryptophan as an endogenous inhibitor of embryo germination in white wheat. | an endogenous germination inhibitor(s) in wheat (triticum aestivum l.) grain has been implicated in seed dormancy and germination, but its identity and mode of action have not been elucidated. we isolated and identified an endogenous germination inhibitor in white wheat grain and compared its activity with that of known compounds. a water extract of wheat bran chromatographed on sephadex lh-20 yielded an inhibitory fraction that was detected by bioassay on embryos excised from dormant wheat seed ... | 1988 | 16666322 |
| proton extrusion by wheat roots exhibiting severe aluminum toxicity symptoms. | the mechanisms of al rhizotoxicity are not known, but disruption of membrane function has been a persistent hypothesis. the objective of this study was to establish whether cells of al-cultured wheat roots (triticum aestivum l. cv tyler) exhibiting severe al toxicity symptoms were capable of vigorous proton extrusion. the membrane electrical potential difference (e(m)) was measured in individual cells throughout the first centimeter of root tips during perfusion with al solutions similar to or m ... | 1988 | 16666319 |
| long-term in vitro culture of wheat grains. | wheat (triticum aestivum, triticum durum) grains were excised immediately following fertilization and cultured until maturity. a rachis fragment attached to the grain was required to ensure an increase in grain size for the first 10 days following fertilization. a (14)c-labeling study revealed that 8-day-old grains accumulated more dry matter into the ethanol-insoluble fraction when grown on agar rather than when immersed in liquid medium. light enhanced the absorption of sucrose from the medium ... | 1988 | 16666317 |
| identification of a complete set of isogenic wheat/rye d-genome substitution lines by means of giemsa c-banding. | a complete set of isogenic wheat/rye d-genome substitutions were produced by crossing an inbred line of spring rye secale cereale l. cv. "prolific" to a tetraploid wheat, the a-and b-genomes of which had previously been extracted from hexaploid wheat, triticum aestivum l. em thell. cv. "thatcher". after chromosome doubling, the derived hexaploid triticale (x triticosecale wittmack) was backcrossed to 6x "thatcher" and selection for wheat/rye substitution lines was carried out in bcf3 to bcf6 fam ... | 1988 | 24232217 |
| gene differences in heading date, height, seed weight and seed yield between two pure line varieties of triticum aestivum l. | reciprocal sets of homozygous inbred backcross lines were developed by crossing two pure line varieties (baart 46 and ramona) of triticum aestivum l., followed by two backcrosses to each of the two parent varieties, and six to eight generations of selfing. data on each inbred backcross line was obtained from twelve plots (from replications in three years). five genes were responsible for over 95% of the genetic variation for heading date. these genes had pleiotropic effects on plant height that ... | 1988 | 24232197 |
| diversity and evolution of chloroplast dna in triticum and aegilops as revealed by restriction fragment analysis. | restriction fragment analysis of chloroplast (cp) dnas from 35 wheat (triticum) and aegilops species, including their 42 accessions, was carried out with the use of 13 restriction enzymes to clarify variation in their cpdnas. fourteen fragment size mutations (deletions/insertions) and 33 recognition site changes were detected among 209 restriction sites sampled. based on these results, the 42 accessions of wheat-aegilops could be classified into 16 chloroplast genome types. most polyploids and t ... | 1988 | 24232195 |
| improved somatic embryogenesis in wheat by partial simulation of the in-ovulo oxygen, growth-regulator and desiccation environments. | the effects of o2, growth-regulators and desiccation on callus growth and somatic embryo (embryoid) development were investigated in cultures of immature embryos of two lines of triticum aestivum l. callus and embryoid formation were induced on media that contained n(6)-furfurylamin-opurine (kinetin) and either 2,4-dichlorophenoxyacetic acid or 3,6-dichloro-o-anisic acid, either with or without abscisic acid (aba). cultures containing differentiated embryoids were then exposed to high concentrat ... | 1988 | 24221880 |
| callus formation and plantlet regeneration from protoplasts derived from suspension cultures of wheat (triticum aestivum l.). | protoplasts were isolated from anther-derived suspension cultures of commercial wheat (triticum aestivum l. cv. chris). the protoplasts were released enzymatically and isolated by centrifugation on a sucrose cushion. the isolated protoplasts were initially cultured in a liquid medium in the dark. numerous microcalli were produced under these conditions, some of which differentiated into globular embryos. upon transfer to a solid medium and exposure to 16h/8h light/dark cycle, the protocalli prol ... | 1988 | 24241878 |
| influence of manganese deficiency and toxicity on isoprenoid syntheses. | twenty-eight day old wheat (triticum aestivum l. cv stacy) response to varying mn concentration (10.1-10,000 micromolar) in nutrient solution was measured. manganese concentrations in the most recently matured leaves (blade 1) were 0.21 to 19.03 mmol mn per kilogram dry weight, respectively. fresh and dry weights increased to a maximum at the 5 micromolar mn nutritional level (0.37 millimole mn per kilogram dry weight) and were decreased at mn above and below this concentration. blade 1 chloropl ... | 1988 | 16666235 |
| biochemical data bearing on the relationship between the genome of triticum urartu and the a and b genomes of the polyploid wheats. | to determine whether the triticum urartu genome is more closely related to the a or b genome of the polyploid wheats, the amino acid sequence of its purothionin was compared to the amino acid sequences of the purothionins in triticum monococcum, triticum turgidum, and triticum aestivum. the residue sequence of the purothionin from t. urartu differs by five and six amino acid substitutions respectively from the alpha 1 and alpha 2 forms coded for by genes in the b and d genomes, and is identical ... | 1988 | 3209062 |
| estimating position-time relationships in steady-state, one-dimensional growth zones. | two methods are described for estimating position-time relationships (pathlines) in steady, one-dimensional growth zones. pathlines can be used to provide a time base for spatial data in developmental studies. the methods apply within extension-only zones (zones of growth without cell division) and require data for cell-number densities, or cumulative cell numbers, or mean cell lengths, and for the overall elongation rate of an organ. the first method ("continuous-pathline" method) can be used t ... | 1988 | 24221636 |
| starch synthesis by isolated amyloplasts from wheat endosperm. | the aim of this work was to discover which compound(s) cross the amyloplast envelope to supply the carbon for starch synthesis in grains of triticum aestivum l. amyloplasts were isolated, on a continuous gradient of nycodenz, from lysates of protoplasts of endosperm of developing grains, and then incubated in solutions of (14)c-labelled: glucose, glucose 1-phosphate, glucose 6-phosphate, fructose 6-phosphate, fructose-1,6-bisphosphate, dihydroxyacetone phosphate and glycerol 3-phosphate. only gl ... | 1988 | 24221626 |
| adaptive potential of wheat ribosomes toward heat depends on the large ribosomal subunit and ribosomal protein phosphorylation. | in a study of the translational efficiency of ribosomal subunits as a function of an in vivo temperature pretreatment, ribosomes were isolated from heat-pretreated (36 degrees c) and reference (20 degrees c) wheat seedlings (triticum aestivum l.). the efficiency of recombined subunits in translating polyuridylic acid was assessed. a threefold increase in the rate of incorporation of phenylalanine by ribosomes from heat-pretreated plants was due to the large ribosomal subunit. this adaptive tempe ... | 1988 | 16666185 |
| effects of an intercultivaral chromosome substitution on winterhardiness and vernalization in wheat. | during a study on the genetic control of winterhardiness in winter wheat (triticum aestivum l. group aestivum), a gene that affected vernalization was found on chromosome 3b in the winter wheat cultivar ;wichita.' when chromosome 3b from wichita was substituted into the winter wheat cultivar ;cheyenne,' the resultant substitution line exhibited a spring growth habit. this is unusual since a cross between the cultivars wichita and cheyenne results in progeny that exhibit the winter growth habit. ... | 1988 | 17246432 |
| stress and activity of molybdenum-containing complex (molybdenum cofactor) in winter wheat seeds. | molybdenum, applied in vivo, restored the damage from low temperature with winter wheat (triticum aestivum, var "sadovo 1") grown on acid soil and, in addition, sharply increased productivity (g salcheva, d georgieva, 1982; g salcheva et al., 1977, 1979). two fractions with molybdenum-cofactor activity in seeds were detected. one of them has a molecular weight of about 230 kilodaltons corresponding to xanthine oxidase activity and leaf nitrate reductase activity. the other has a molecular weight ... | 1988 | 16666178 |
| carbon dioxide fixation by detached cereal caryopses. | immature detached cereal caryopses from barley (hordeum vulgare l. var distichum cv midas) and wheat (triticum aestivum l. cv sicco) were shown to be capable of fixing externally supplied (14)co(2) in the light or dark. green cross cells and the testa contained the majority of the (14)c-labeled material. some (14)c-labeled material was also found in the outer, or transparent, layer and in the endosperm/embryo fraction. more (14)c was recovered from caryopses when they were incubated in (14)co(2) ... | 1988 | 16666172 |
| response of two wheat cultivars to co(2) enrichment under subambient oxygen conditions. | two cultivars of wheat (triticum aestivum l. cvs sonoita and yecora rojo) were grown to maturity in a growth chamber within four sub-chambers under two co(2) levels (350 or 1000 microliters per liter) at either ambient (21%) or low o(2) (5%). growth analysis was used to characterize changes in plant carbon budgets imposed by the gas regimes. large increases in leaf areas were seen in the low o(2) treatments, due primarily to a stimulation of tillering. roots developed normally at 5% o(2). seed d ... | 1988 | 16666145 |
| starch biosynthesis in developing wheat grain : evidence against the direct involvement of triose phosphates in the metabolic pathway. | we have used (13)c-labeled sugars and nuclear magnetic resonance (nmr) spectrometry to study the metabolic pathway of starch biosynthesis in developing wheat grain (triticum aestivum cv mardler). our aim was to examine the extent of redistribution of (13)c between carbons atoms 1 and 6 of [1-(13)c] or [6-(13)c]glucose (or fructose) incorporated into starch, and hence provide evidence for or against the involvement of triose phosphates in the metabolic pathway. starch synthesis in the endosperm t ... | 1988 | 16666140 |
| chromosomal location of genes encoding barley (1-->3, 1-->4)-beta-glucan 4-glucanohydrolases. | preparations of dna from wheat (triticum aestivum, cv chinese spring), barley (hordeum vulgare, cv betzes) and six euplasmic wheat-barley addition lines were digested to completion with restriction endonucleases and the products probed by southern blot analysis using a cdna-encoding barley (1-->3, 1-->4)-beta-glucanase isoenzyme ii. it is shown that one of the barley (1-->3, 1-->4)-beta-glucanase genes is located on chromosome 1. | 1988 | 16666137 |
| on the evolution of the adaptation of lophopyrum elongatum to growth in saline environments. | most species of the genus lophopyrum löve (agropyron geartn.) grow in saline environments and are more tolerant of saline stress than the species of the related genus triticum l. a 56-chromosome amphiploid from the cross triticum aestivum cv. chinese spring x lophopyrum elongatum exceeded chinese spring in salt tolerance, measured as plant dry-matter production and seed yield in solution cultures with 250 mm nacl. thus, the adaptation of lophopyrum to saline environments is expressed in the whea ... | 1988 | 16593932 |
| regulation of photosynthesis in nitrogen deficient wheat seedlings. | nitrogen effects on the regulation of photosynthesis in wheat (triticum aestivum l., cv remia) seedlings were examined. ribulose 1,5-bisphosphate carboxylase/oxygenase was rapidly extracted and tested for initial activity and for activity after incubation in presence of co(2) and mg(2+). freeze clamped leaf segments were extracted for determinations of foliar steady state levels of ribulose 1,5-bisphosphate, triose phosphate, 3-phosphoglycerate, atp, and adp. nitrogen deficient leaves showed inc ... | 1988 | 16666124 |
| dark respiration during photosynthesis in wheat leaf slices. | the metabolism of [(14)c]succinate and acetate was examined in leaf slices of winter wheat (triticum aestivum l. cv frederick) in the dark and in the light (1000 micromoles per second per square meter photosynthetically active radiation). in the dark [1,4-(14)c]succinate was rapidly taken up and metabolized into other organic acids, amino acids, and co(2). an accumulation of radioactivity in the tricarboxylic acid cycle intermediates after (14)co(2) production became constant indicates that orga ... | 1988 | 16666093 |
| the role of calcium ions in phytochrome-controlled swelling of etiolated wheat (triticum aestivum l.) protoplasts. | protoplasts from dark-grown wheat (triticum aestivum l.) maintained at a constant osmotic potential at 22°c, were found to swell upon red irradiation (r) and the effect was negated by subsequent far-red light (fr), indicating phytochrome involvement. swelling only occurred when ca(2+) ions were present in the surrounding medium, or were added within 10 min after r. furthermore, mg(2+), ba(2+) or k(+) could not replace this requirement for ca(2+). the presence of k(+) did not enhance the ca(2+)-d ... | 1988 | 24221423 |
| the integration of whole-root and cellular hydraulic conductivities in cereal roots. | the hydraulic conductivities of excised whole root systems of wheat (triticum aestivum l. cv. atou) and of single excised roots of wheat and maize (zea mays l. cv. passat) were measured using an osmotically induced back-flow technique. ninety minutes after excision the values for single excised roots ranged from 1.6·10(-8) to 5.5·10(-8) m·s(-1)·mpa(-1) in wheat and from 0.9·10(-8) to 4.8·10(-8) m·s(-1)·mpa(-1) in maize. the main source of variation was a decrease in the value as root length incr ... | 1988 | 24221410 |
| linked sucrose synthase genes in group-7 chromosomes in hexaploid wheat (triticum aestivum l.). | a cdna library from developing wheat endosperm was screened for sucrose-synthase clones using a maize cdna probe corresponding to the sh1 locus under non-stringent conditions. five positive clones were isolated and initially classified into two types on the basis of their relative ability to hybridize with the probe and of their partial restriction maps. determination of the nucleotide sequences indicated homology between the two types of wheat clones, with type 1 showing higher homology to the ... | 1988 | 2838390 |
| substitution analysis of callus induction and plant regeneration from anther culture in wheat (triticum aestivum l.). | the genetic determination of callus induction, total plant regeneration and green plant regeneration from anther culture were studied using a "chinese spring"/"cheyenne" substitution series. all the three characteristics were found to be polygenically determined, but their inheritance was independent from one another. the 7a and 18 chromosomes had a considerable effect on callus induction. in the case of total plant regeneration the most influential chromosome "as the 3a while the 2d chromosome ... | 1988 | 24241549 |
| ice-encasement injury to microsomal membranes isolated from winter wheat crowns : ii. changes in membrane lipids during ice encasement. | the physical properties and chemical composition of microsomal membranes were examined during a 7 day period of ice encasement in crown tissue of winter wheat (triticum aestivum l. cv norstar). membrane damage, detected as an increase in microviscosity and electrolyte leakage, began between 1 and 3 days of icing, and was associated with a reduction in the recovery of microsomal membranes from stressed tissue, an increase in the microsomal free fatty acid:total fatty acid ratio, and a decrease in ... | 1988 | 16665979 |
| a novel method for increasing the frequency of somatic embryogenesis in wheat tissue culture by nacl and kcl supplementation. | the effect of nacl, kcl and licl on the growth and morphogeneis of tissue cultures originating from immature embryos of four wheat (triticum aestivum l.) and one triticale (triticosecale)varieties was investigated. the morphogenetic pathway to plant regeneration in chinese spring wheat was determined as incomplete somatic embryogenesis because the differentiation and subsequent germination of the shoot apices happened in the early phase of embryo development. culture medium supplemented by nacl ... | 1988 | 24241416 |
| determination of endogenous abscisic acid levels in immature cereal embryos during in vitro culture. | levels of endogenous abscisic acid (aba) in immature wheat (triticum aestivum cv. timmo) and barley (hordeum vulgare cv. golden promise) embryos have been determined by enzyme-linked immunosorbent assay. embryos of both cereal species showed an increase in aba content during development on the parent plant. immature embryos were excised and cultured in vitro on nutrient media that led to precocious germination or on media containing 9% (w/v) mannitol that maintained their developmental arrest. b ... | 1988 | 24226187 |
| effects of soil strength on the relation of water-use efficiency and growth to carbon isotope discrimination in wheat seedlings. | the ratio of carbon accumulation to transpiration, w, of wheat (triticum aestivum l.) seedlings increased with increasing soil strength, measured as soil penetrometer resistance, and this was already apparent at the two leaf stage. the ratio was negatively correlated with carbon isotope discrimination, in accord with theory. this means that decrease in intercellular partial pressure of co(2) accounted for an important part of the increase in w with increasing soil strength. despite a lower co(2) ... | 1988 | 16665888 |
| nitrogen uptake by wheat seedlings, interactive effects of four nitrogen sources: no3-, no2-, nh4+, and urea. | the net influx (uptake) rates of no3-, nh4+, no2-, and urea into roots of wheat (triticum aestivum cv yecora rojo) seedlings from complete nutrient solutions containing all four compounds were monitored simultaneously. although urea uptake was too slow to monitor, its presence had major inhibitory effects on the uptake of each of the other compounds. rates of no3-, nh4+, and no2- uptake depended in a complex fashion on the concentration of all four n compounds. equations were developed which des ... | 1988 | 11538231 |
| exploring the limits of crop productivity. i. photosynthetic efficiency of wheat in high irradiance environments. | the long-term vegetative and reproductive growth rates of a wheat crop (triticum aestivum l.) were determined in three separate studies (24, 45, and 79 days) in response to a wide range of photosynthetic photon fluxes (ppf, 400-2080 micromoles per square meter per second; 22-150 moles per square meter per day; 16-20 hour photoperiod) in a near-optimum, controlled-environment. the co2 concentration was elevated to 1200 micromoles per mole, and water and nutrients were supplied by liquid hydroponi ... | 1988 | 11537442 |
| influence of edta on the atpase activities of plasma membranes from winter wheat roots. | plasma membrane vesicles were purified from roots of winter wheat seedlings (triticum aestivum l. cv. marton-vásári-8) by aqueous polymer two-phase partitioning. the atpase activity of vesicles in the presence of ca was independent of but in the presence of mg depended on the edta concentration in the atpase assay. the potassium stimulation and vanadate inhibition of the mgatpase also depended on the edta concentration. consequences of these results are briefly discussed. | 1988 | 2976563 |
| gibberellin modulation of phosphatidyl-choline turnover in wheat aleurone tissue. | phosphatidyl choline (pc) is synthesised in wheat (triticum aestivum l. cv. flanders) aleurone tissue during early germination when new endomembranes are being formed. although gibberellic acid does not ostensibly affect pc levels, it inhibits the incorporation of choline and differentially and specifically modulates the turnover of the n-methyl and methylene carbons of the choline headgroup of pc. gibberellic acid has no effect on turnover of the phosphate moiety of either pc or the other major ... | 1987 | 24226069 |
| ice encasement injury to microsomal membranes from winter wheat crowns : i. comparison of membrane properties after lethal ice encasement and during a post-thaw period. | the functional and physical properties of cellular membranes isolated from triticum aestivum, cvs norstar and fredrick, were altered coincident with changes in composition after a lethal ice-encasement stress and further during a 6 hour post-thaw period. crowns encased in ice for a duration which inhibited regrowth, exhibited enhanced rates of electrolyte leakage. furthermore, the recovery of total microsomal protein and phospholipid declined, suggesting that some membrane degradation had been i ... | 1987 | 16665805 |
| genetic control of nadh dehydrogenase-1 and aromatic alcohol dehydrogenase-2 in hexaploid wheat. | the genetic control of nadh dehydrogenase-1 (ndh-1) and aromatic alcohol dehydrogenase-2 (aadh-2) was investigated in triticum aestivum cv. chinese spring. evidence was obtained that ndh-1 is active as a monomer and is encoded by genes located in the p arms of the homoeologous group 4 chromosomes. the ndh-1 gene loci located in 4ap, 4bp, and 4dp were designated ndh-a1, ndh-b1, and ndh-d1, respectively. aadh-a2 was previously reported to be located in 6aq; in this study, aadh-b2 and aadh-d2 were ... | 1987 | 3329906 |
| a reverse transcriptase-like activity of wheat (triticum aestivum) embryo microsomal fraction. | a reverse transcriptase-like activity was isolated from germinating wheat (triticum aestivum) embryos. the activity was found to be associated with a microsomal fraction (70,000 g pellet) of the embryo homogenate. the microsome-associated enzyme prefers homologous polyadenylated rna to any other polynucleotides as template and requires all four deoxyribonucleoside triphosphates for maximal activity. the reaction product appears in the incubation mixture in the form of an rna-dna hybrid, which ca ... | 1987 | 2449165 |