An improved transformation protocol for studying gene expression in hairy roots of sugar beet (Beta vulgaris L.)

A transformation protocol, based on co-inoculation with two strains of Agrobacterium, Agrobacterium tumefaciens LBA4404 and A. rhizogenes 15834 containing a binary vector with the GUS gene, was established for the induction of transgenic hairy roots from sugar beet (Beta vulgaris L.) explants. It resulted in marked improvement in the formation of hairy roots and the integration of the binary vector T-DNA into the host genome. Of 250 inoculated sugar beet hypocotyls, 84% yielded hairy roots 5–7 days after inoculation, of which 70% were co-transformed with the binary vector T-DNA. To determine stable expression of alien genes in hairy roots, the nematode resistance gene Hs1 ^pro-1 was used as a reporter gene. In addition, molecular marker analysis was applied to monitor stable incorporation of a translocation from the wild beet B. procumbens. The molecular analysis and the nematode (Heterodera schachtii) resistance test in vitro demonstrated that the genomic structure and the expression of the Hs1 ^pro-1 -mediated nematode resistance were well-maintained in all hairy root cultures even after repeated sub-culture. Received: 25 November 1997 / Revision received: 26 May 1998 / Accepted: 15 June 1998     

An extracellular enzyme from Fusarium solani f. sp. phaseoli which catalyses hydration of the isoflavonoid phytoalexin, phaseollidin

Among the antimicrobial phytoalexins produced by Phaseolus vulgaris (French bean) are the prenylated isoflavonoids kievitone and phaseollidin. Two enzyme activities, kievitone hydratase and phaseollidin hydratase, occur in culture filtrates of the bean pathogen, Fusarium solani f. sp. phaseoli, and catalyse similar hydration reactions on the dimethylallyl moieties of the phytoalexins. The enzymes nearly co-purified during hydroxyapatite chromatography followed by preparative native gel electrophoresis. Eluates from successive slices taken from the native gel were assayed for both activities. Although they were not completely separated in the native gel, the activity profiles indicated that the two activities were distinct. The Km of phaseollidin hydratase for phaseollidin was approximately 7 microM.     

Multigenerational experimental simulation of climate change on an economically important insect pest

Long‐term multigenerational experimental simulations of climate change on insect pests of economically and socially important crops are crucial to anticipate challenges for feeding humanity in the not‐so‐far future. Mexican bean weevil Zabrotes subfasciatus, is a worldwide pest that attacks the common bean Phaseolus vulgaris seeds, in crops and storage. We designed a long term (i.e., over 10 generations), experimental simulation of climate change by increasing temperature and CO₂ air concentration in controlled conditions according to model predictions for 2100. Higher temperature and CO₂ concentrations favored pest''s egg‐to‐adult development survival, even at high female fecundity. It also induced a reduction of fat storage and increase of protein content but did not alter body size. After 10 generations of simulation, genetic adaptation was detected for total lipid content only, however, other traits showed signs of such process. Future experimental designs and methods similar to ours, are key for studying long‐term effects of climate change through multigenerational experimental designs.     

Lectin-like proteins accumulate as fragmentation products in bean seed protein bodies

The gene sequence of the Phaseolus vulgaris L. seed lectin-like protein (LLP) and its precursor ( 40 kDa) which is associated with the endoplasmic reticulum has been described, while the molecular characteristics of the mature protein and its cellular localization are still unknown. Our data, obtained using antibodies raised against a fusion protein, which was produced in Escherichia coli and contained most of the LLP sequence, indicate that mature LLP accumulates in the protein bodies of cotyledon cells. LLP consists of several polypeptides in the M_r range 15 000 to 20 000, which are a result of proteolytic fragmentation of the protein precursor.     

Hydrogen evolution by co-immobilized Chlorella vulgaris and Clostridium butyricum cells

Whole cells of Chlorella vulgaris and Clostridium butyricum were co-immobilized in 2% agar gel. NADP was suitable as an electron carrier. The rate of hydrogen evolution increased with increasing NADP concentration. The optimum conditions for hydrogen evolution were pH 7.0 and 37°C. The immobilized C. vulgaris-NADP-immobilized Cl. butyricum system continuously evolved hydrogen at a rate of 0.29–1.34 μmol/h per mg Chl for 6 days. On the other hand, the system without NADP evolved only a trace amount of hydrogen.     

A numerical model of seasonal foraging characteristics of successful underground colonies of Vespula vulgaris (Hymenoptera,Vespidae) in England

Summary. A numerical model has been developed to calculate the total number of transits in each worker foraging category for the 170 days of development of a successful colony. Seven categories of workers are considered: two of outgoers (earth carriers and non-earth outgoers), and five of incomers (pulp, flesh, full fluid, and partial fluid carriers, and empty incomers). The model allows for variation in the length of the foraging day and for hypothetical smaller and larger colonies. Estimates of each category are given for the queen, smaller and larger worker colony. Estimates of 1.3–4.5 million, for smaller and larger colonies, each of incomer and outgoer transits are calculated from the model. The slight excess of outgoer over incomer transits could be accounted for, in part, by the mortality of workers away from the nest. Percentages of each worker category are given for the pre-exponential small-cell, exponential small-cell and large-cell colonies. It is hypothesized that there is a balance between fluid and solid transits for efficient brood rearing. There may be restraints in the social wasp system that restrict brood rearing. Estimates which are independent of the foraging model are calculated for the number of loads to create the nest cavity and build the pulp nest which broadly agree with the model outputs.Received 15 July 2004; revised 15 December 2004; accepted 23 December 2004.     

Growth,photosynthesis, and metabolism of sugar beet at an early stage of exposure to elevated CO<Subscript>2</Subscript>

The effects of CO₂ concentration (C _a) on growth, photosynthesis, and the activity of enzymes associated with the translocation and assimilation of CO₂ were studied in sugar beet (Beta vulgaris L. subsp. saccharifera, cv. Ramonskaya) plants. The plants were grown in controlled-climate chamber to the stage of 3–4 leaves and then used in experiments. Experimental plants were exposed in boxes to doubled C _a (700 µl/l, 2C plants), whereas control plants were kept in a chamber with ambient atmosphere (350 µl/l, 1C plants). As compared with 1C plants, in 3 and 8 days, the leaf area of 2C plants increased by 14 and 26%, respectively. The rate of their photosynthesis (P _n) measured in 3, 6, and 8 days increased by 85, 47, and 52%, respectively, whereas in normal air, the values of P _n in 2C plants were by 12, 19, and 15% lower than in 1C plants. After 8-day growth, the content of soluble carbohydrates in the leaves of 2C plants attained 7.2%, being by 80% greater than in 1C plants; the content of starch did not exceed 3%. The total content of chlorophylls a and b in the leaves of 2C plants was by 14% greater than in 1C plants, but their ratio was essentially the same. The level of protein in 2C plants was by 13.4% lower than in 1C plants. The activity and content of Rubisco in 1C and 2C plants were similar. As compared with 1C plants, in 2C plants the activity of soluble carbonic anhydrase (sCA) was lower by 34% in 3 days and by 18% in 8 days; the activity of carbonic anhydrase of membrane preparations (mCA), was lower by 24 and 77%, respectively. Catalase activity in 2C plants became by 8% lower than in 1C plants only after 8 days. A reduction in the photosynthetic ability of 2C plants in ambient atmosphere, a decrease in activity of sCA and, especially, of mCA observed together with invariable activity and content of Rubisco in the leaf extracts are interpreted as early symptoms of acclimation of young plants of sugar beet to elevated CO₂.Translated from Fiziologiya Rastenii, Vol. 52, No. 2, 2005, pp. 184–190.Original Russian Text Copyright © 2005 by Ignatova, Novichkova, Mudrik, Lyubimov, Ivanov, Romanova.This revised version was published online in April 2005 with a corrected cover date.     

Variation in the quality of Vespula vulgaris (L.) queens (Hymenoptera: Vespidae) and its significance in wasp population dynamics

Abstract

Density‐related variation in queen quality has been proposed as a possible mechanism regulating population fluctuations in Vespula species. We investigated annual variation in the quality (size, weight, and fat content) of adult V. vulgaris queens representing four stages of their life cycle (spring, founding, developing, and emerged) taken from six sites in beech forest, South Island, New Zealand. For each queen the dry weight, head width, and thorax length was measured. For a subsample of queens, the fat content was determined by ether extraction. The size of queen cells was measured from a subsample of nests. Size, weight, and fat content of queens varied between wasp colonies and sites. The smallest juvenile queens were under‐represented in the reproductive population. There was no direct link between body size and food supply. Size and weight of developing queens increased as the number of cells in the nest increased. The size of the queen cells varied significantly among layers in a nest and among nests. The under‐representation of small queens in the reproductive population suggests that queen quality may affect survival and/or competitive ability by increasing winter fat storage, nest building activity, and/or success in usurpation disputes.     

Interaction between Meloidogyne incognita and Pochonia chlamydosporia and their effects on the growth of Phaseolus vulgaris

An experiment was conducted to test the effect of different doses of 2, 4 and 8?g/2?kg of soil of Pochonia chlamydosporia against the root-knot nematode (Meloidogyne incognita) on Phaseolus vulgaris. It was observed that inoculation of plant with the nematode alone, and 15?days prior to fungal inoculation, reduced the plant growth when compared with the plant with fungal application followed by the nematode. Plant length, fresh and dry weight, chlorophyll, carotenoid, protein contents and nitrate reductase activity decreased in nematode-infested plants. Application of higher dose of 8?g/2?kg of soil of P. chlamydosporia increased all the plant growth parameters as well as biochemical parameters. Highest number of galls per root system was recorded on the plants infested with nematode but not treated with the fungus. However, application of fungus prior to nematode inoculation improved the plant growth and reduced the number of galls and the number of egg masses per root system.