Competition by, and chemical control of, natural weed populations in spring-sown field beans (Vicia faba)

A field experiment was done in 1974 to determine the effect of the presence of weeds for different periods on the yield of field beans (Vicia faba cv. Maris Bead). A critical period of weed competition of 2 wk duration occurred from 3 to 5 wk after 50% crop emergence. When weeds were not controlled, seed yield was reduced by 46%, from 4–6 to 2–5 t/ha. In another experiment, in 1975, there was no evidence of a critical period. Seed yield was reduced by 48%, from 2–9 to 1–5 t/ha, when weeds were not controlled. Pre-emergence applications of simazine and of dimefuron, a new soil-residual herbicide, effectively controlled weeds and bean seed yields were similar to those of the regularly hand-weeded control. Dinoseb-acetate and early, but not late, post-emergence applications of dimefuron controlled weeds satisfactorily. Dimefuron is potentially useful in spring-sown field beans because it can be applied pre- or early post-emergence without damaging the crop.     

The chemical characterization of favin, a lectin isolated from Vicia faba.

We have determined the subunit structure of the glucose- and mannose-binding lectin favin, from Vicia faba. The molecule is composed of two nonidentical polypeptide chains held together by noncovalent interactions. We have determined the complete amino acid sequence of the smaller alpha chain (Mr = 5,571) and shown that it is homologous to the alpha chain of the lectins from lentil and pea and to residues 72 to 120 of concanavalin A (Con A). The larger beta chain (Mr = 20,000) contains carbohydrate and is homologous to the beta chain of lentil, pea, soybean, peanut, and red kidney bean lectins and is homologous to a portion of the Con A molecule beginning at residue 122. Favin also contains a minor component, beta' (Mr = 18,700), that closely resembles the beta chain but lacks carbohydrate and may, on the basis of apparent molecular weight, lack some part of the COOH-terminal region of the polypeptide chain. Although favin is similar to Con A, it, like the lentil and pea lectins, appears to lack residues corresponding to positions 1 to 71 of Con A. Because these residues contribute significantly to the carbohydrate binding site of Con A, the lack of this region in the otherwise homologous lectin favin suggests that the carbohydrate binding site of favin differs from that of Con A or that the region represented by residues 1 to 71 of Con A is located in a different portion (i.e. in the beta chain) of the favin molecule.     

Cytological studies on the antimetabolite action of 2, 6-diaminopurine in Vicia faba roots

At a concentration of 9.6 x 10(-5)M, 2,6-diaminopurine (DAP) completely inhibited cell enlargement, cell division, and DNA synthesis (determined by microphotometric measurement of Feulgen dye) in Vicia faba roots. Inhibition of cell enlargement was partially reversed by adenine, guanine, xanthine, adenosine, and desoxyadenosine. Guanine and the nucleosides gave the greatest reversal, suggesting that one point of DAP action upon cell enlargement is a disruption of nucleoside or nucleotide metabolism, possibly during pentosenucleic acid synthesis. DAP inhibited cell division by preventing onset of prophase. At the concentrations used it had no significant effect on the rate or appearance of mitoses in progress. Inhibition of entrance into prophase was not directly due to inhibition of DNA synthesis since approximately half of the inhibited nuclei had the doubled (4C) amount of DNA. Adenine competitively reversed DAP inhibition of cell division, giving an inhibition index of about 0.5. Guanine gave a slight reversal while xanthine, hypoxanthine, adenosine, and desoxyadenosine were inactive. A basic need for free adenine for the onset of mitosis was suggested by this reversal pattern. Meristems treated with DAP contained almost no nuclei with intermediate amounts of DNA, indicating that DAP prevented the onset of DNA synthesis while allowing that underway to reach completion. The inhibition of DNA synthesis was reversed by adenine, adenosine, and desoxyadenosine although synthesis appeared to proceed at a slower rate in reversals than in controls. Inhibition of DNA synthesis by DAP is probably through nucleoside or nucleotide metabolism. A small general depression of DNA content of nuclei in the reversal treatments was observed. This deviation from DNA "constancy" cannot be adequately explained at present although it may be a result of direct incorporation of DAP into DNA. The possible purine precursor, 4-amino-5-imidazolecarboxamide gave no reversal of DAP inhibition of cell elongation and cell division and only a slight possible reversal of inhibition of DNA synthesis.     

Absence of DNA repair replication after chemical mutagen damage in Vicia faba

Exposure of human (Hela) cells to the mutagens 4-nitroquinoline-1-oxide (4NQO) and N-methyl-N′-nitro-nitrosoguanidine (MNNG) produces damage in DNA that is repaired by a mechanism involving the insertion of new bases into DNA (repair replication). Vicia faba root tips, either from soaked seeds containing non-proliferating cells or from growing roots, do not perform detectable amounts of repair replication even though the mutagens inhibit DNA synthesis and cause chromosome aberrations. In view of similar failures to resolve excision in Chlamydomonas, Haplopappus, and Nicotiana after irradiation with UV light and in Vicia faba after X-irradiation it appears that plants in general might lack this repair process.     

Microdissection of M chromosome in Vicia faba and its library construction]

Microdissection and microcloning technique was employed to construct the library of M chromosome in Vicia faba. The M chromosomes were microdissected with a micromanipulator and were put into a 0.5 ml Eppendorf tube, then digested with Sau3A. Sau3A linker adaptors were ligated to the end of chromosome DNA fragments, and two rounds of PCR were carried out with one chain of linker adaptor as the primer. The PCR products ranged in size from 300 base pair (bp) to 3000 bp with predominant fragments from 500 bp to 1500 bp. Southern hybridization analysis confirmed that PCR products originated from Vicia faba genome. The second round PCR products were cloned and about 102,000 recombinants were obtained. 118 recombinants were selected randomly for analysis. The inserts ranged in size from 150 bp to 3000 bp with an average of 690 bp. Dot blot was carried out for 100 clones with DIG labeled Vicia faba genome DNA as probes. The result revealed that 51% were low and unique copy sequences, 49% were repetitive sequences. M chromosome DNA library has not been reported before.     

'Rinrei', a brassinosteroid-deficient dwarf mutant of faba bean (Vicia faba L.)

A dwarf mutant of broad bean ( Vicia faba L.), the variety Rinrei, has been created by γ -ray irradiation. Rinrei is characterized by dark green leaves and by reduced plant length, internode and petiole length, shoot weight, and number of branches. Genetic analysis of hybrids between Rinrei and two wild-type lines indicated that these characteristics are controlled by a single recessive gene. The phenotype of Rinrei was restored to that of the wild type by application of brassinolide, but not by GA₃. Qualitative and quantitative analysis by gas chromatography–mass spectrometry indicated that 24-methylenecholesterol and isofucosterol accumulated in Rinrei to levels more than 30 times higher than in the wild type. In contrast, Rinrei had lower than wild-type levels of campesterol, sitosterol and brassinosteroids. Therefore, Rinrei is a brassinosteroid-deficient mutant defective in sterol C-24 reduction. The gene was tentatively designated as brassinosteroid deficient dwarf 1 , bdd1 , which seems to be a homologue of Arabidopsis dwf1 ( dim , cbb1 ) and pea lkb .     

On the mechanism of cytoplasmic male sterility in the 447 line of Vicia faba

The trait of cytoplasmic male sterility, expressed in plants bearing the 447 cytoplasm of Vicia faba, is uniquely and positively correlated with the presence of a linear double-stranded RNA molecule (dsRNA) 16.7 kb in size. Restriction enzyme digestion profiles of mitochondrial DNA isolated from fertile and cytoplasmic malesterile (CMS) lines do show a limited number of specific differences in fragment intensities and mobilities. However, mitochondria isolated from the progeny of the cross CMS × Restorer line contain DNA with an identical restriction profile as the male-sterile parent: moreover, subsequent generations are completely and permanently fertile, even upon segregation of the nuclear restoration gene. Southern hybridizations, using cDNA clones as probes, reveal homology between the CMS-associated dsRNA and the nuclear genome of both sterile and fertile lines. The regions cloned, representing approximately 22% of the total dsRNA sequence, show no homology to organelle DNA. We have not been able to stably transmit the dsRNA to fertile lines of V. faba or any other plant species, using a variety of standard virological techniques.     

Changes in the Lipid and Fatty Acid Composition of Vicia faba Mesophyll Protoplasts Induced by Isolation

The lipid and fatty acid compositions of mesophyll protoplastsof Broad bean (Vicia faba) have been analysed by gas chromatography.The results indicate that protoplast isolation triggered therapid hydrolysis of several membrane lipids, notably phosphatidylcholineand monogalactosyldiacylglycerol. The decrease of these lipidswas compensated for by an increase in the amount of the neutrallipid fraction. Analyses of the fatty acid compositions suggestthat phosphatidylcholine from the microsomes and monogalactosyldiacylglycerolfrom the chloroplast were degraded to diacylglycerol and freefatty acids and used for the biosynthesis of triacylglycerols. (Received April 20, 1984; Accepted September 27, 1984)     

Floral display in Vicia faba, and the distribution of a flower thrips, Kakothrips pisivourus

The flower thrips Kakothrips pisivorus (Westwood) (Thysanoptera) breeds in flowers of Vicia faba L. (Leguminosae). The egg and larval stages combined outlast the flowers. Each larva must move between the flowers on a plant at least once. The presence of old larvae in buds demonstrates successful inter-floral movement by larvae. If thrips leaving a dying flower transfer to a new flower nearby, old larvae will accumulate at the end of a spatial sequence of adjacent short-lived flowers. The distribution of K. pisivorus on the plant was investigated. Old larvae did accumulate in flowers at the end of V. faba racemes, as predicted. The relationship between floral lifespan, floral display, and flower inhabitants is discussed. The distribution of the thrips is relevant to sampling procedures.

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Disposition des fleurs de Vicia faba et distribution de Kakothrips pisivorus

Résumé K. pisivorus Westwood (Thysanoptera) se développe dans les fleurs de Vicia faba L. (Leguminosae). Les durées combinées des stades embryonnaires et larvaires dépassent celles des fleurs. Chaque larve doit changer de fleur sur la plante au moins une fois. La présence de larves agées dans les bourgeons provient de l'existence de déplacements larvaires interfloraux réussis. Si les thrips quittant une fleur sénescente gagnent une nouvelle fleur voisine, les vieilles larves s'accumuleront à la fin d'une série de fleurs de courte durée de vie. La distribution de K. pisivorus sur la plante a été examinée; des fleurs du même âge ont été échantillonées dans 3 positions sur les inflorescences. Il n'y a pas eu d'effet significatif de la position des fleurs sur les oeufs et larves 1. Les adultes passent une partie de la journée sur les fleurs les plus proches peut-être parce qu'elles sont les plus hautes. A l'extrémité des inflorescences de V. faba, l'accumulation de larves agées était supérieure à celle prévue. La discussion porte sur les relations entre la durée de vie des fleurs, leur position et les insectes que les occupent. La distribution des thrips influe sur les techniques d'échantillonnage.

     

Isolation and purification of generative cells from fresh pollen of Vicia faba L.

A technique named two-step osmotic shock was developed for isolating generative cells (GCs): pollen grains were incubated in 20% sucrose solution and shocked by adding water. This caused the pollen grains to burst and release their contents including GCs. By subsequent filtration and centrifugation the isolated GCs were purified. The viability of GCs before and after purification was confirmed by fluorescein diacetate (FDA) test. This procedure offers a rapid and effective means to obtain living GCs in quantities.Abbreviations GC Generative cell - FDA Fluorescein diacetate     

Glutamine synthetase in the chloroplasts of Vicia faba

Summary A glutamine synthetase has been localised in the chloroplasts of Vicia faba. The enzyme has requirements for Mg²⁺ and ATP in the biosynthetic reaction and in addition will catalyse a -glutamyl transferase reaction in the presence of Mn²⁺ and arsenate. The enzyme is inhibited by AMP, CTP, glycine and alanine. These results are discussed in relation to the possible chloroplastic synthesis of nucleotide bases. Estimations of glutamine amide-2-oxoglutarate amino transferase (oxido-reductase) have demonstrated only low levels of activity in the chloroplast extracts. This enzyme is generally active in organisms where GS has an assimilary role. It is coneluded that glutamine synthetase has a biosynthetic and not an assimilatory role in the chloroplast.     

Growth Substances in the Roots of Vicia faba

An investigation has been made into the growth regulators presentin ethanol extracts of the seedling roots of Vicia faba afterseparation on paper partition chromatograms, using segmentsof Avena coleoptiles and mesocotyls and of Pisum sativum.rootsas biological assay material. Acetonitrile purification shows the presence of at least threeauxins running in isobutanol: methanol: water, at Rfs of 0–0·25,0·4–0·6, and 0·65–0·95;the latter may represent two different auxins. A similar, butclearer, picture is shown by the ether-soluble acid fraction.Here an auxin at Rf 0–0·25 also stimulates rootgrowth and could be ‘accelerator ’. A second atRf 0–0·25 is an indole compound which inhibitsroot growth and does not seem to be be IAA. A third at Rf 0·8–1·0is also a root-growth inhibitor and gives no indole reaction.The ‘inhibitor ß’ complex was demonstrated(Rf 0·65–0·85) together with a number ofother inhibitors at lower Rf value. The ether-soluble neutral component also contains auxins orauxin precursors. The water-soluble, ether-insoluble fraction contains four readilyinterconvertible substances with auxin properties. They allappear to inhibit root growth and give no indole reaction.     

Biosynthesis of the phytoalexin wyerone in Vicia faba

In contrast to earlier results [1-¹⁴C] acetate, [2-¹⁴C] malonate and [n 9,10-³H] oleate show significant incorporations into wyerone and related Vicia faba phytoalexins, following infection by Botrytis cinerea.     

Isolation and Purification of ABA Binding Protein from Abaxial Epiderm of Vicia faba Leaf

Abscisic acid (ABA) was efficiently cross-linked to Sepharose 4B (6 ~8 mmol ABA/L gel) by an ann of 10-atom carbon chain. Solubilized ABA-BP (ABA binding protein) was allowed to bind to the gel, while unrelated proteins were removed by washing with a gradient of NaC1 buffer. The ABA-BP was eluted with 1 mmol/L ABA. Since ABA at high concemration can interfere with both the binding activity assay and protein analysis, the fractions eluted with ABA were passed through a Sephadex G-25 column to remove the ABA. Fractions containing the binding activity were pooled, concentrated with uhm-fihration. The maximum binding capacity (BMAX) of the purified ABA-BP was 58.33 nmol/g protein, and the Kd was 21 nmol/L, with an approximately 112 folds increase of purity. SDS-PAGE identification of the purified ABA-BP revealed a major protein band with a molecular weight of about 44.2 kD, and a purity of approximately 90 %.