Dwarf French Bean Research Articles

The effect of nitrogenous fertilizer on the seed yield, and yield components ofPhaseolus vulgaris

Phaseolus vulgarisis grown in the U.K. primarily for its edible immature pods (dwarf French beans). The possibility of also using this species as a combinable break crop in south-east England was investigated during 1972–80 when trials were undertaken on the nitrogen fertilizer requirement for commercial seed production.

Influence of rhizosphere on the nutrient status of dwarf French beans

French bean seedlings grown on choline, ammoniacal and nitrate forms of nitrogen together with equivalent basal application of P as KH2PO4 were tested for nutrient uptake from the rhizosphere. Statistical tests on soil (rhizosphere and non-rhizosphere) and plant (root and shoot) revealed that with the exception of P, levels of all other estimated macro-(Na+, K+, Ca2+, Mg2+) and micro-nutrients (Fe2+, Mn2+, Zn2+) were significantly changed after 42 days growth as compared to 21 days growth period. The higher uptake into shoots of Na+, K+, Fe2+, Mn2+, Zn2+ and H2PO4− and higher biomass accumulation in the rhizosphere were associated with lower rhizosphere pH. The uptake of Ca2+ and Mg2+ increased with higher rhizosphere pH. While ammoniacal and choline forms decreased rhizosphere pH and increased the P uptake, nitrate form reversed the trend showing significant inverse relationship between shoot phosphate and rhizosphere pH. Calcium and iron were associated with an inhibition of the translocation of P from root to shoot. However, no causal relationships could be established. Both shoot weight and shoot P content were closely associated with a number of rhizosphere soil parameters.

Effect of rhizosphere pH on the availability and uptake of Fe, Mn and Zn

In pot experiments the relationships between rhizosphere pH, the extractable levels of Fe, Mn and Zn in the soil and their uptake into the roots and shoots of dwarf French beans have been studied. Variations in rhizosphere pH were induced by applying three different sources of nitrogencholine phosphate, ammonium phosphate and calcium nitrate-to an initially homogenised soil (preadjusted to either pH 7 or 8). The rhizosphere pH was found to be significantly lower following the application of either ammonium or choline phosphates and to be increased by calcium nitrate treatment. The Fe and Zn contents of both shoot and root were inversely proportional to rhizosphere pH. The Mn contents also increased with decreasing pH but a sharp increase was apparent below pH 5.5. The shoot Fe, Zn and Mn content were significantly correlated with the extractable levels determined in the rhizosphere and non-rhizosphere soil.

The Effect of Pod Removal on the Translocation of14C Photosynthate from Leaves inPhaseolus VulgarisL. cv Lochness

SummaryTrifoliate leaves of the dwarf French bean cv Lochness were exposed under field conditions to 14C during reproductive development. Labelled photosynthate was mainly retained within each nodal unit, the branch pods acting as the main sinks. Sink removal 48 h before exposing the leaves to 14C enhanced translocation to pods above and below the fed node.

Elicitor modulation of the turnover of l-phenylalanine ammonia-lyase in French bean cell suspension cultures

1. (1) The mechanisms underlying the trasient increase in phenylalanine ammonia-lyase activity during phaseollin accumulation in cell suspension cultures of Dwarf French bean ( Phaseolus volgaris) have been investigated using density labelling with 2H from 2H 2O coupled with residual analysis of the equilibrium distribution of enzyme activity in high-resolution KBr denstiy gradients. 2. (2) The resolution achieved in this system is sufficient to allow quantitative analysis of the relative proportions of light, unlabelled, pre-existing enzynes and heavy, labelled, newly synthesised enzyme. 3. (3) Elicitor released by heat treatment of cell walls of Colletotrichum lindemuthainum, the causal agent of anthracnose disease of French bean, caused a marked but transient increase in phenylalanine ammonia-lyase activity concomitant with the onset of phaseolllin accumulation in the bean cultures. The induction of enzyme activity was highly dependent on elicitor concentration, with maximum induction occurring in two discrete concentration ranges; at an instermediate elicitor concentration, or at supra-optimal elicitor concentrations, no enzyme induction was observed. 4. (4) At low concentrations of elicitor the induction of enzyme was entirely a result of elicitor stimulation of the rate of de novo enzyme production. In contrast, at higher elicitor concentrations the increase in enzyme activity was accompanied by a marked apparent stabilization of the enzyme in vivo, and the rapid but transient increase in enzyme activity was achieved by a programme of reciprocal changes in the rate constant for de novo enzyme production and the rate constant for removal of enzyme activit. Such reciprocal control of the rates of enzyme production and removal may be crucial in determing the magnitude and duration of the phytoalexin defence response. 5. (5) Information on the specific activity of 2H label in the amino acid pools was obtained from analysis of the equilibrium distribution of residual, labelled activity. This showed directly that the turnover of the amino acids pools was fast relative to the turnover of phenylalanine ammonia-lyase and, hence, the rate of enzyme labelling was not limited by the rate of labelling of the amino acid pools. Elicitor treatment had no effect on the specific activity of label in the amino acid pools from which phenylalanine ammonia-lyase is synthesised.

Modulation of L-phenylalanine ammonia-lyase by pathway intermediates in cell suspension cultures of dwarf French bean (Phaseolus vulgaris L.)

The increase in extractable phenylalanine ammonia-lyase (PAL;EC 4.3.1.5.) activity induced in French bean cell suspension cultures in response to treatment with autoclaved ribonuclease A was inhibited by addition of the phenylpropanoid pathway intermediates cinnamic acid, 4-coumaric acid or ferulic acid. The effectiveness of inhibition was in the order cinnamic acid>4-coumaric acid>ferulic acid. Cinnamic acid also inhibited the PAL activity increase induced by dilution of the suspensions into an excess of fresh culture medium. Addition of low concentrations (<10(-5)M) of the pathway intermediates to cultures at the time of application of ribonuclease gave variable responses ranging from inhibition to 30-40% stimulation of the PAL activity measured at 8 h. Following addition of pathway intermediates to cultures 4-5 h after ribonuclease treatment, rapid increases followed by equally rapid declines in PAL activity were observed. The cinnamic acid-stimulated increase in enzyme activity was unaffected by treatment with cycloheximide at a concentration which gave complete inhibition of the ribonuclease-induced response. However, cycloheximide completely abolished the subsequent decline in enzyme activity. Treatment of induced cultures with α-aminooxy-β-phenylpropionic acid (AOPPA) resulted in increased but delayed rates of enzyme appearance when compared to controls not treated with the phenylalanine analogue. The results are discussed in relation to current views on the regulation of enzyme levels in higher plants.

Effects of combined nitrogen on anapleurotic carbon assimilation and bleeding sap composition in Phaseolus vulgaris L.

Dwarf french beans, Phaseolus vulgaris L., were grown with or without inoculation with rhizobia (strain 3644), and with or without a combined nitrogen source (nitrate or ammonium ions). The distribution of radioactivity into products of dark (14)CO2 assimilation was studied in roots or nodules from these plants. A detailed study was also made of the distribution and rates of excretion of nitrogen in xylem bleeding sap in 28 day old plants grown on the various sources of nitrogen. Whereas detached nodules accumulated radioactive glycine, serine and glutamate when incubated with (14)CO2, bleeding sap from plants root fed (14)CO2 contained low levels of radioactivity in these compounds but higher levels in allantoin. Chemical analysis showed allantoin to be the major compound transported in the xylem of nodulated plants, whether or not they were fed on combined nitrogen. In contrast uninoculated plants accumulated mainly amino acids in the bleeding sap, the amount and chemical composition of which depended on the combined nitrogen source.

Methylation analysis of cell-wall material from parenchymatous tissues of phaseolus vulgaris and phaseolus coccineus

Cell-wall material (CWM) from parenchymatous tissues of pods of dwarf french and runner beans was prepared by sequentially extracting the wet ball-milled tissues with 1% aqueous sodium deoxycholate, phenol-acetic acid-water, and 90% aqueous dimethyl sulphoxide. The overall monosaccharide compositions of the preparations were similar, and each contained small but significant amounts of hydroxyprolinerich glycoproteins. Methylation analysis of the CWM revealed the following main glycosidic linkages in descending order of concentration: 4-linked galacturonic acid, 4-linked glucose, 4-linked galactose, 5-linked arabinose, 2-linked rhamnose, and 4-linked xylose. The major branch-points were those through C-6 of glucose, C-3 of arabinose, and C-4 of rhamnose. Arabinose, xylose, and galactose constituted the non-reducing end-groups. The general structural features of the CWM are discussed.

Stimulation of de novo synthesis of l-phenylalanine ammonia-lyase in relation to phyto alexin accumulation in colletotrichum lindemuthianum elicitor-treated cell suspension cultures of french bean ( phaseolus vulgaris)

1. (1) The regulation of the accumulation of the isoflavonoid-derived phytoalexin phaseollin in cell suspension cultures of Dwarf French Bean ( Phaseolus vulgaris) has been investigated. 2. (2) An elicitor preparation from cell walls of Colletotrichum lindemuthianum, the causal agent of anthracnose disease of French bean, caused a marked accumulation of phaseollin in the cultures. The elicitor induced phaseollin accumulation to a level of 60% that obtained with the artificial elicitor autoclaved ribonoclease A and was maximally active at a concentration (weight basis) of at least 50 times lower than required for maximall response to ribonuclease. 3. (3) Elicitor preparations from cell walls of Phytophthora megasperma var. sojae, a fungal pathogen of soybean, and Botrytis cinerea, the common grey mould, were much less effective than the C. lindemuthianum wall-released elicitor. 4. (4) There was a marked but transient increase in the extractable activity of phenylalanine ammonia-lyase, the enzyme catalysing the first reaction in the biosynthesis of phaseollin from l-phenylalanine, in response to the elicitor from C. lindemuthianum. 5. (5) Comparative density labelling with 2H from 2H 2O indicated that the elicitor stimulates de novo synthesis of phenylalanine ammonia-lyase, and that this is an early event in the phytoalexin defence response. 6. (6) These findings provide the basis of a scheme for elicitor induction of phytoalexin accumulation.

Endogenous Estradiol-17 β in Phaseolus vulgaris

Evidence based on chromatographic (TLC, Lipidex, GLC), mass spectrometric (GC-MS, selective current ion monitoring) and radioimmunoassay procedures is presented for the occurrence of estradiol-17β (E 2 ) in the dwarf French bean Phaseolus vulgaris . Methods for the isolation of such compounds from plant extracts are detailed and problems of the quantification of E 2 in phenolic extracts are discussed.

Studies on plant growth‐regulating substances. XLIII. 2 ‐Chloro ‐3 ‐phenoxypropionitriles

SUMMARYA number of ring substituted 2‐chloro‐3‐phenoxypropionitriles have been prepared and their plant growth‐regulating activity has been assessed in the wheat coleoptile, pea segment and pea curvature tests, and also by spray treatments on tomato and dwarf French bean plants. The activities of these compounds are compared with those of previously studied 2‐chloro‐3‐phenylpropionitriles and the results are discussed in terms of chemical structure/biological activity relationships and mode of action.

Growth of Plants in Different Oxygen Concentrations

Growth of Plants in Different Oxygen Concentrations

Adaptive Responses to Temperature in Dwarf French Beans, Phaseolus vulgaris L.

Adaptive Responses to Temperature in Dwarf French Beans, Phaseolus vulgaris L.

Auxins and cytokinins exuded during formation of roots by detached primary leaves and stems of dwarf French bean (Phaseolus vulgaris L.)

Hypocotyls of detached stems standing in culture solution produced adventitious roots sooner than did petioles of detached primary leaves. An auxin, probably indol-3-ylacetic acid, appeared in the solutions before the hypocotyls or petioles produced roots. After attaining a maximum, the amounts of auxin in the solutions decreased as fewer roots were formed. Two cytokinins were found in the culture solutions; one had a similar Rf to zeatin, the other ran more slowly on chromatograms. The amounts of cytokinin in the solutions were associated with root formation. Stems soon died unless their hypocotyls formed roots, but the primary leaves survived without roots forming provided a callus formed on the petiole. Hence adventitious roots, or callus tissues, may have produced cytokinins that replaced those produced by the original roots, found in sap exuded from the stem stumps, and were essential for survival of the stems and leaves.

Effect of CCC and glycine betaine on growth and growth‐substance content of primary leaves of dwarf Frenchbean (Phaseolus vulgaris L.)

SUMMARYCCC (2‐chloroethyltrimethylammonium chloride) decreased growth of primary leaves and stem internodes above the hypocotyl of dwarf French bean, probably because it decreased the amount of auxin produced by interaction between tryptophan and phenolic esters in the primary leaves. Growth of leaves was less affected than that of stems, and the gibberellin content of the primary leaves, previously shown to be associated with their expansion, was unaffected by CCC. CCC delayed death of the primary leaves, the breakdown of chlorophyll, and the increase in auxin associated with death of bean leaves. CCC had less effect on the growth of leaf discs, probably because they are not sites of growth‐substance production. Glycine betaine, a quaternary ammonium compound similar to CCC, did not affect growth of bean plants, their metabolism of growth substances or the longevity of their primary leaves, but inhibited growth of leaf discs, probably directly.

Conversion of tryptophan to auxin by phenolic esters from leaves of dwarf french bean ( Phaseolus vulgaris L.)

Macerated bean leaves ( Phaseolus vulgaris) produced more auxin when incubated at pH 7·5 in the presence of toluene for 2 days with tryptophan than without. Boiled or autoclaved leaves did not produce auxin when incubated alone, but did so after adding tryptophan. Conversion of tryptophan to auxin during incubation of macerated leaves was attributed to phenols, later identified as esters of caffeic, ferulic and p-coumaric acids. The phenolic esters extracted from bean leaves promoted growth of wheat coleoptile sections only when assayed with tryptophan, and produced auxin only when incubated or hydrolysed with tryptophan. Caffeic acid reacted with tryptophan like the bean phenols but ferulic and p-coumaric acids were less effective. Phosphate buffer, pH 7·5, removed phenolic esters, but not auxins, from the surface of bean leaves, and like the extracted bean phenols they produced auxin when incubated with tryptophan.

Changes in Auxins in Expanding and Senescent Primary Leaves of Dwarf French Bean (Phaseolus vulgaris)

A bound, unextractable auxin, or auxin precursor, in the primary leaves of dwarf French bean was converted to a form, probably indol-3yl-acetic acid, extractable in ethyl acetate, by macerating leaves in pH 7 5 phosphate buffer and incubating them at 37—38° C for 2 days in the presence of toluene or hibitane. Boiling the leaves before macerating and incubating them prevented the release of bound auxin. This bound auxin was also released when macerated leaves were hydrolysed with normal potassium hydroxide at ioo° C for 2 hours. The amounts of free auxin and tryptophan in senescent primary leaves increased as their bound auxin and chlorophyll decreased. Removing the apical growing region immediately above the node bearing the primary leaves delayed their senescence and the con version of their bound to free auxin.

Effect of Removing Cotyledons, Apical Growing Region, or Trifoliate Leaves on the Growth and Growth-substance Content of Dwarf French Bean (Phaseolus vulgaris)

The growth of the primary leaf on intact plants was compared with that on plants from which the cotyledons, apical growing region, or trifoliate leaves had been removed. Removing the cotyledons early decreased the final area of the primary leaves, this response being partially accounted for by a decrease in their cell number, and increased the concentration (but not the quantity) of gibberellin and auxin in them. This response was not altered by applying any of several growth substances. Early removal of the apical growing region increased the final area of the primary leaves; it also increased the gibberellin content and concentration at Day 10 but did not influence the auxin content and concentra tion. Primary leaf expansion was affected less by detaching young trifoliate leaves than by removing the entire apical growing region.

Inhibition of Chlorophyll Synthesis by High Concentrations of Carbon Dioxide

High concentrations of carbon dioxide inhibit the greening of etiolated plants. In the presence of 20% oxygen, concentrations of carbon dioxide of 10% and above inhibited the production of chlorophyll in etiolated leaves of barley, wheat, and dwarf French bean. On return to air, recovery from this inhibition took place rapidly. High concentrations of carbon dioxide were also inhibitory when illumination was discontinuous (2-msecond flash separated by 3-minute dark period) during which photosynthetic activity was adjudged to be negligible. The inhibition was alleviated by feeding with delta-amino levulinic aid, implying that the site of inhibition was early in the sequence of chlorophyll synthesis. 15 references, 3 figures, 1 table.

Effect of Seed Treatment on Growth and Growth-substance Content of Dwarf French Beans (Phaseolus vulgaris)

The longer the seeds of dwarf French bean (Phaseolus vulgaris) were soaked in water before sowing, the smaller were the seedlings they produced. Soaking for 24 hours removed only little dry matter, but detectable amounts of a gibberellin and a betaine. The amounts of these two removed increased with increased time of soaking. Long soaking of seeds decreased the amounts of gibberelin and auxin in the cotyledons, and of gibberellin, auxin, and betaine in the primary leaves of seedlings. Aerating, cooling, or increasing the volume of water in which the seeds were soaked also retarded the growth of the seedlings, but did not affect the amount of growth substance removed from the seeds or contained in the cotyledons. The deleterious effect of soaking seeds was not alleviated by treating the seeds or seedlings with gibberellic acid or glycine betaine. Although larger seedlings were produced by heavy than by light seeds, their cotyledons and primary leaves contained similar concentrations of growth substances.