Barley seedlings

Pitman, M.G., Lauchli, A. Stelzer (1981). Ion distribution in roots of barley seedlings as measured by electron probe X-ray micro-analysis. Plant Physiology, 66, 673-9. 

Dasgupta, J. Bewley, J.D. (1984). Variations in protein synthesis in different regions of greening leaves of barley seedlings and effects of imposed water stress. Journal of Experimental Botany, 35, 1450-9. 

Ramagopal, S. (1987). Salinity stress induced tissue-specific proteins in barley seedlings. Plant Physiology, 84, 324-31. 

Both H-thymidine incorporation and radiolabeled leucine incorporation techniques have been recently used to determine bacterial activity and growth in the rhizosphere of barley seedling (28), Bacteria were initially released from the rhizosphere using homogenization and centrifugation before adding the labeled substrates. The cell incorporation rate was twice as high in the rhizosphere than in bulk soil. In addition, both the leucine and thymidine incorporation rates increased with the distances from the root tip (28). 

Figure 3 Root fingerprints of Pseudomimets sp. associated with barley seedlings showing the production of siderophore by actively growing bacteria located in the zone of elongation behind the root tips. Root.s were pressed on to an iron-deficient minimal medium selective for Pseudomonas. After growth of the colonies, the production of siderophore was visualized by exposure of the agar plate to ultraviolet light, which causes the siderophore to Huoresce.

Plant uptake of chlordecone from the soil via the roots, and volatilization of chlordecone from soil with plant uptake via the leaves were found to be negligible in a closed laboratory system using barley seedlings. This indicates that bioaccumulation of chlordecone by plants (lowest on the terrestrial food chain) is very unlikely based on its log soil adsorption coefficient of almost 4.0 (Topp et al. 1986). No information on the uptake of chlordecone by plants under field conditions was located. 

Alius, M.A., Brereton, R.G., and Nickless, G. (1989), The Use of Experimental Design, Multilinear Regression, ANOVA, Confidence Bands and Leverge in a Study of the Influence of Metals on the Growth of Barley Seedlings, Chemom. Intel. Lab. Sys., 6, 65-80. 

Table II. Effect of Micro-organisnvs cind Bieir Metabolites Formed During 14 Days Deconposition of Plant Residues on Longest Root Length (mm) of Barley Seedlings...

Effect of water stress on susceptibility of barley to aphids. Barley seedlings were subjected to water stress. These plants accumulated among other compounds proline and glycine-betaine (Table IV). Also, the more stressed plants were the most susceptible to aphids. The cultivar used in this experiment lacked gramine. However, when a gramine-containing cultivar was used gramine concentration was not affected by water stress. 

HV006 Mendez, J. Indole auxins in barley seedlings. Phytochemistry 1967 6 313-315. 

Vassilev, G. N., and N. P. Mashev. Synthesis, chemical structure and cy-tokinin-like activity of some derivatives of N-Phenyl N -alk-yl or arylt thiourea and their influence on the nitrogen metabolism in barley seedlings. Biochem Physiol Pflanz 1974 165 467. 

Another type of test using young barley seedlings was developed by Green (7). This test is more quantitative for certain oil and hydrocarbon toxicity studies than those tests previously mentioned. Tests of hydrocarbons on barley seedlings were in general agreement with the evaluations obtained in the other tests. 

Pea and barley seedlings were grown in the greenhouse at 60 to 70 F. The plants were placed in chambers at temperatures of 5 intervals from 40 to 85 F. After one day in the temperature chambers, the plants were sprayed at the rate of 100 gallons per acre with a 50-50 mixture of Varsol No. 1 and n-tetradecane. Injury ratings made 3 days afer the treatment showed only a very slight tendency for toxicity to increase with a rise in temperature (correlation coefficient = 0.426, regression coefficient = 0.029). 

Shewry, P.R. Miflin, B.J. Properties and regulation of aspartate kinase from barley seedlings (Hordeum vulgare L.). Plant Physiol., 59, 69-73 (1977)... 

Ward, M.R., Tischner, R. Huffaker, R.C. (1988). Inhibition of nitrate transport by anti-nitrate reductase IgG fragments and the identification of plasma membrane associated nitrate reductase in roots of barley seedlings. Plant Physiology 88, 1141-5. 

Warner, R.L. Huffaker, R.C. (1989). Nitrate transport is independent of NADH and NAD(P)H nitrate reductases in barley seedlings. Plant Physiology 91, 947-53. 

Concerning nitrate uptake and assimilation (Albuzio et al., 1986) in barley seedlings incubated with HS from a grassland soil and their fractions—nitrate reductase (NR), glutamate dehydrogenase (GDH),and glutamine synthetase (GS) activities— were analyzed together with the rate of nitrate uptake. The enzymatic activities turned out to be stimulated by the treatment of unfractioned humus extract with increases compared to controls of 65%, 35% and 45% respectively. 

Albuzio, A., Ferrari, G., and Nardi, S. (1986). Effects of humic substances on nitrate uptake and assimilation in barley seedlings. Can. J. Soil Sci. 66,731-736. 

Several enzymes involved in the biosynthesis of phenethylamines in plants have been studied. A tyrosine carboxy-lyase (decarboxylase) isolated from barley seedlings and barley roots has been studied in considerable detail (347-349). The enzyme is rather specific for L-tyrosine and meta-tyrosine ort/io-tyrosine and L-dopa are decarboxylated slowly. Tyrosine carboxylase activity was also demonstrated in wheat and maize (348). Cytisus scoparius contains dopa car-boxy-lyase which decarboxylates d- and L-dopa at about the same rate (350). Tyrosine is decarboxylated 15 times slower. A similar enzyme has been found in the alga Monostroma juscum (174). 

ALS was isolated from barley seedlings as a 0-33% Ammonium Sulfate precipitate and examined for inhibition by TP. It is apparent from Figure 5 that the enzyme is very sensitive to the compound. The 1(50) value (concentration required for 50% inhibition) was calculated to be 0.047 uM. This value is within the range reported for CS tested against ALS from different species (19). Imidazolinones are less potent with 1(50) values in the range 2-12 uM (26). ALS isolated from several species and their 1(50) values for TP is shown in Table I. 

SA in Table II - nmoles/hr/mg protein and N.D - not detectable. Tobacco, soy cultures and barley seedlings were the best source of ALS, both in terms of specific activity and total units. The enzyme preparations from all sources were unstable in buffer solutions in spite of protective thiol agents. The inactivation of ALS in the crude extract of tobacco showed a distinct biphasic kinetics, implying the presence of at least two isozymes (unpublished observations). The presence of two ALS genes in tobacco (29) and at least three in microorganisms (18) has also been noted by other workers. ALS from barley was most amenable to purification. Table III gives a profile for the rapid purification of this enzyme with high recovery. 

The variety of aldehyde oxidases discovered in other plants have similarities to the maize enzyme, but also have some very important differences. Enzymes contained in a cell wall fraction from barley seedlings were able to oxidize IAAld to form IAA at a pH optimum of 7 and Km of 5 pmol 1 1, which was very similar to the enzyme found in maize.113 Two aldehyde oxidases from potato have also been identified 101 they had a similar pH optimum (between 7 and 8), but preferred aliphatic aldehydes to aromatic aldehydes. Although oat and cucumber aldehyde oxidases have been shown to oxidize IAAld to produce IAA,102 114 the oat enzyme had a lower pH optimum and higher Km than the maize enzyme, and the cucumber enzyme was inhibited by synthetic auxin and activated by 2-mercaptoethanol, which was not true for the maize enzyme. The difference in the enzymes makes it difficult to envision a common evolutionary origin for the IAAld pathway in plants if these particular enzymes are involved in each case. 

Schiff s base (Illb), which is then degraded by a reverse Michael reaction to the protonated 3-methyleneindolenine (IIIc). Addition of ammonia then yields 3-aminomethylindole, which on methylation affords gramine (III). This attractive hypothesis finds support in the recent isolation from barley seedlings of both 3-aminomethylindole and 3-methyl-aminomethylindole (57b). It is also supported by the demonstration that 3-aminomethylindole can be methylated to 3-methylaminomethylindole... 

Two natural derivatives of 2-hydroxyputrescine have been found in wheat Ar-(4-coumaroyl)- and Ar-feruloyl-2-hydroxyputrescine (10 and 11, respectively). By acid-catalyzed hydrolysis (S)-(+)-2-hydroxyputrescine and ferulic acid and 4-coumaric acid were formed, respectively. By comparison to synthetic Ar-carbamoylputrescine (12), the structure of a compound isolated from barley seedlings was confirmed (39). 

Several agmatine (16) (Scheme 2) derivatives have been isolated from barley seedlings. All are conjugates of coumaric acid and possess antifungal activity. 

Recently, it has been shown that an enzyme present in extracts of the shoots of barley seedlings synthesizes both 4-coumaroylagmatine and the hordatines from 4-coumaroyl coenzyme A and [U-14C]agmatine (45). ... 

Shibko, S., and Edelman, J., 1957, Randomization of the carbon atoms in glucose and fructose during their metabolism in barley seedlings. Biochim. Biophys. Acta 25 642-644. 

Zhao FG., Qin P. Protective effect of exogenous polyamines on root tonoplast function against salt stress in barley seedlings. Plant Growth Regulation 2004 42(2) 97-103. 

The EB effects on cell ultrastructure were studied with the first leaf of 10-day-old barley seedlings (cv.Vingr) Leaf segments were prelnoubated In EB solution (10 °M), or water, for 2 h and were then Incubated In 0.5 M NaCl solution during 24 h In the presence or absence of EB. Cells of control leaves had the nuclei of nucleonema type with diffused and condensed chromatin (Figure 7 A) Chioroplasts revealed a well developed membrane system of... 

Scheumann V, Schoch S, Rudiger W (1999) Chlorophyll b Reduction During Senescence of Barley Seedlings. Planta 209 364... 

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