Structure-function relations of carbohydrates by neoglycolipid arrays

Fabrication and application of carbohydrate microarray for analyzing human serum antibody-carbohydrate interaction

We introduced a strategy for preparing a carbohydrate microarray and demonstrated its utility for characterizing carbohydrate binding and activities. We isolated the lipopolysaccharide (LPS) components from different bacteria and explored the possibility of immobilizing these glycoconjugates on a high-binding polystyrene plate. Carbohydrate-specific combination was examined by observing the binding of the blood group B analogic LPS O-polysaccharide from Escherichia coli on the high-binding polystyrene plate and anti-B from a broad spectra antibody of human blood serum. Strong binding of antibodies was screened, as it was evident that relative response value is two times higher than control. The hybridization results indicated that this method is a reliable technique for the detection of human intestinal bacteria and is expected to be applied in diagnostics and seroepidemiology.

Toxins for transgenic resistance to hemipteran pests

The sap sucking insects (Hemiptera), which include aphids, whiteflies, plant bugs and stink bugs, have emerged as major agricultural pests. The Hemiptera cause direct damage by feeding on crops, and in some cases indirect damage by transmission of plant viruses. Current management relies almost exclusively on application of classical chemical insecticides. While the development of transgenic crops expressing toxins derived from the bacterium Bacillus thuringiensis (Bt) has provided effective plant protection against some insect pests, Bt toxins exhibit little toxicity against sap sucking insects. Indeed, the pest status of some Hemiptera on Bt-transgenic plants has increased in the absence of pesticide application. The increased pest status of numerous hemipteran species, combined with increased prevalence of resistance to chemical insecticides, provides impetus for the development of biologically based, alternative management strategies. Here, we provide an overview of approaches toward transgenic resistance to hemipteran pests.

Transgenic tobacco expressing Zephyranthes grandiflora agglutinin confers enhanced resistance to aphids

Plant lectins have been reported as transgenic resistance factors against a variety of insect pests. Herein, homologous analysis demonstrated that Zephyranthes grandiflora agglutinin (ZGA) exhibited high similarity with other monocot mannose-binding lectins (MBLs). Phylogenetic analysis revealed that it had taxonomical relationships with insecticidal MBLs. Subsequently, a plasmid expression vector pBI121 containing zga gene (pBIZGA) was constructed using the zga sequence, under the control of CaMV35S promoter and nos terminator. pBIZGA was then integrated into the genome of Nicotiana tabacum L. Polymerase chain reaction and Southern blot analysis demonstrated that this zga gene was integrated into the plant genome. Western blotting and agglutinating activity analysis also showed that transgenic tobacco plants expressed different levels of ZGA. Carbohydrate inhibition analysis indicated that recombinant ZGA and the native shared the same carbohydrate-binding specificity. Moreover, genetic analysis confirmed Mendelian segregation (3:1) of the transgenic in T1 progenies. In planta bioassays on T0 plants and their progenies indicated that expressed ZGA had an effect on reducing the survivability and fecundity of tobacco aphids (Myzus nicotianae). These findings demonstrate that the novel zga gene of ZGA can be expressed in crop plants susceptible to various sap-sucking insects.