Bt Eggplant Project in Bangladesh: History, Present Status, and Future Direction.

The purpose of this article is to provide information on the history, accomplishments, and future direction of the Bt brinjal (eggplant) program in Bangladesh, formerly under the Agricultural Biotechnology Support Project II, now the South Asia Eggplant Improvement Partnership (SAEIP). The India-based Maharashtra Hybrid Seed Company (Mahyco) developed an eggplant expressing Cry1Ac (EE-1) for control of the eggplant fruit and shoot borer (EFSB). In a partnership among Mahyco, USAID, Sathguru Management Consultants and Cornell University EE-1 was provided to the Bangladesh Agricultural Research Institute (BARI) who bred it into local varieties. After regulatory approval, four varieties were distributed to 20 farmers who harvested Bt brinjal in 2014. Adoption in subsequent years has increased rapidly so that, in 2018, 27,012 farmers used this technology. This article provides background information on the process leading up to current adoption levels, the level of control of EFSB achieved and the economic benefits of Bt brinjal. Efforts on stewardship, farmer training and communication are discussed. In order to ensure the long-term future of the partnership, we discuss the need to enhance involvement of the private sector in the production and stewardship of Bt eggplant. Bt brinjal is the first genetically engineered crop to be commercially released in Bangladesh, and other GE crops are in the pipeline. Hence, success of the Bt brinjal partnership is likely to affect the future of other GE crops in Bangladesh, as well as other parts of the world where biotechnology is needed for food security and environmental safety.

Dual regulation of a chimeric plant serine/threonine kinase by calcium and calcium/calmodulin.

A chimeric Ca2+/calmodulin-dependent protein kinase (CCaMK) gene characterized by a catalytic domain, a calmodulin-binding domain, and a neural visinin-like Ca2+-binding domain was recently cloned from plants (Patil, S., Takezawa, D., and Poovaiah, B. W. (1995) Proc. Natl. Acad. Sci. U. S. A. 92, 4797-4801). The Escherichia coli-expressed CCaMK phosphorylates various protein and peptide substrates in a Ca2+/calmodulin-dependent manner. The calmodulin-binding region of CCaMK has similarity to the calmodulin-binding region of the alpha-subunit of multifunctional Ca2+/calmodulin-dependent protein kinase (CaMKII). CCaMK exhibits basal autophosphorylation at the threonine residue(s) (0.098 mol of 32P/mol) that is stimulated 3.4-fold by Ca2+ (0.339 mol of 32P/mol), while calmodulin inhibits Ca2+-stimulated autophosphorylation to the basal level. A deletion mutant lacking the visinin-like domain did not show Ca2+-stimulated autophosphorylation activity but retained Ca2+/calmodulin-dependent protein kinase activity at a reduced level. Ca2+-dependent mobility shift assays using E. coli-expressed protein from residues 358 520 revealed that Ca2+ binds to the visinin-like domain. Studies with site-directed mutants of the visinin-like domain indicated that EF-hands II and III are crucial for Ca2+-induced conformational changes in the visinin-like domain. Autophosphorylation of CCaMK increases Ca2+/calmodulin-dependent protein kinase activity by about 5-fold, whereas it did not affect its Ca2+-independent activity. This report provides evidence for the existence of a protein kinase in plants that is modulated by Ca2+ and Ca2+/calmodulin. The presence of a visinin-like Ca2+-binding domain in CCaMK adds an additional Ca2+-sensing mechanism not previously known to exist in the Ca2+/calmodulin-mediated signaling cascade in plants.

Overexpression of the actin gene is associated with the morphogenesis of Candida albicans.

A progressive increase in the synthesis of actin mRNA was observed by Northern blot analysis, when cells were induced to form germ tubes at 37 degrees C by N-acetyl-D-glucosamine. Presence of trifluoperazine, a calmodulin inhibitor, or incubation of cells at 25 degrees C, or by replacing N-acetyl-D-glucosamine with glucose which inhibited germ tube formation lowered this synthesis. Furthermore, in vitro translation of total RNA revealed an increase in the synthesis of actin (45 kDa) during germ tube formation. These results suggest for the first time that the expression of actin gene is regulated during morphogenesis of C. albicans.

Role of nutritional status of the cell in pH regulated dimorphism of Candida albicans.

Stationary phase cells of Candida albicans are under the control of glucose repression, as indicated by the inhibition of germ tube formation by glucose. This 'glucose effect' was absent in starved cells which were derived from similar stationary phase cells. Moreover, starved cells required glucose for germ tube formation, suggesting that it was depletion of energy reserves which was the main factor overriding the 'glucose repression machinery' during starvation. High concentration of phosphate in Lee's medium was the reason for the reduced ability of the starved cells to form germ tubes at pH 4.5 (20% of cells compared to 88% at pH 6.8). However, when phosphate was replaced or its concentration reduced, germ tube formation occurred as frequently at pH 4.5 as at pH 6.8. This 'phosphate effect' was not observed in stationary phase cells, as they were already repressed by glucose.

Involvement of calcium, calmodulin and protein phosphorylation in morphogenesis of Candida albicans.

N-Acetyl-D-glucosamine-induced germ tube formation in Candida albicans at 37 degrees C was accompanied by an increase in the rate of protein phosphorylation. The calmodulin antagonist trifluoperazine and the Ca2+ ionophore A23187, which inhibited germ tube formation, also reduced the rate of phosphorylation. The rate of phosphorylation was also reduced when cells were incubated at 25 degrees C, which favoured yeast-phase growth. Two-dimensional SDS-PAGE analysis of phosphoproteins from germ-tube-forming and yeast cells revealed two germ-tube-specific and three yeast-specific phosphoproteins. Germ tubes and hyphae had more calmodulin activity than yeast cells, irrespective of the germ-tube-inducing condition used. As a first step towards understanding the inhibitory effect of trifluoperazine on germ tube formation, calmodulin from C. albicans was purified to homogeneity. It was heat stable, and displayed a pronounced Ca2(+)-induced shift in electrophoretic mobility.

Aeromonas sobria in bubaline (water buffalo) abortion: growth requirement, biochemical characters, antibiotic susceptibility, experimental pathogenicity and serology.

A. sobria was isolated unexpectedly on Campylobacter selective medium from abortion specimens of 16 buffaloes. All strains (AS1-AS16) required Campylobacter growth supplement (sodium pyruvate, sodium metabisulphate and ferrous sulphate) and 10% C02 atmosphere on primary isolation. They were unusually sensitive to bile salt and failed to grow on MacConkey's agar. Biochemically, these strains were homogeneous but antibiogram profile and physiological/other characters revealed a moderate heterogeneity. In vitro antibiotic sensitivity pattern showed a number of antibiotics effective whereas only a few (penicillin and co-trimoxazole) ineffective against these strains. It took 9 days for 3 x 10(8) A. sobria organisms/ml in 5 ml quantity to terminate the pregnancy in an experimentally infected buffalo via iv route. Foetal and placental lesions were classical as that of field cases. The infection evoked serum antibody response. Apparently disease-free buffalo sera were devoid of such antibodies.

Serratia marcescens infection associated with early abortion in cows and buffaloes.

Serratia marcescens was isolated in pure culture from cases of septic abortion in 4 cows on one farm and 10 buffaloes on two other farms. A reddish vaginal discharge was observed after abortion in all animals and in the internal organs of the aborted fetuses. All but two of the isolates produced prodigiosin, and two of the isolates from buffaloes were atypical in that they fermented raffinose. O-serological, bacteriophage and bacteriocin typing revealed four different strains. All cows were infected by the same strain, and this strain was also isolated from the semen of a breeding bull on the same farm. In another farm a strain of serotype O 14 was isolated from 6 of 10 buffaloes, and two other distinct strains were isolated from the remainder. The strain from the cattle was sensitive to gentamicin and so were two of the buffalo isolates. The infected cows were treated with intra-uterine gentamicin and the organism disappeared from cervical mucus after 3 days. Each animal after abortion showed a raised titre of agglutinating antibody to their respective isolate. A survey of 1172 healthy buffaloes and cattle gave an incidence of 1.8% with raised titres towards S. marcescens.

Yersinia enterocolitica associated with third trimester abortion in buffaloes.

A group of buffaloes aborted at the third trimester of their gestational period. Yersinia enterocolitica was isolated from all cases. All aborted animal sera had high antibody titres against Y. enterocolitica antigen which crossreacted significantly with Brucella abortus antigen. All animals were culturally negative after intrauterine infusion of gentamycin sulphate (160 mg/day) for three consecutive days.

Lipid and haemoprotein oxidation in meat emulsions.

Emulsions of refined additive-free lard, egg albumin and water were designed to study the effect of haemoproteins, iron salts and sodium chloride on lipid oxidation. It was found that ferric haematin pigments (metmyoglobin, methaemoglobin and heat denatured myoglobin and haemoglobin) were all catalysts of lipid oxidation whereas the oxy and carboxy derivatives were not effective. Emulsions prepared using meat of high and low metmyoglobin contents supported these findings. At the levels present in meat products, both ferrous and ferric salts were only very weak catalysts of the lipid oxidation compared with the ferric haematin complexes. Sodium chloride (1·5%) also possessed little or no pro-oxidant activity in these systems. Emulsions prepared from fresh meat and fats from various sources and of different histories indicated that although, in model systems, peroxidising lipids can catalyse the oxidation of myoglobin, in meat and meat-based emulsions the effect is of minimal importance.