Cloning and characterization of a novel animal lectin expressed in the rat sublingual gland.

We cloned a rat gene that is expressed primarily in the sublingual gland and named the predicted 503 amino-acid protein SLAMP (sublingual acinar membrane protein). SLAMP has 63% homology with human ERGIC-53-like protein, a member of the family of animal L-type lectins. Using a cDNA probe for SLAMP mRNA and rabbit antisera against SLAMP, we examined the expression and localization of SLAMP in major rat organs and tissues. With both Northern and Western blot analyses, abundant expression of SLAMP was demonstrated predominantly in the sublingual gland, with single sizes of the mRNA and protein 1.8 kb and 50 kDa, respectively, but not in other organs or tissues, including the parotid and submandibular glands. With immunohistochemistry, SLAMP was localized to the mucous acinar cells, but not to the serous demilunes or the duct system. With immunoelectron microscopy, SLAMP was localized predominantly to regions corresponding to the ER-Golgi intermediate compartment. Besides the sublingual gland, SLAMP immunoreactivity was also demonstrated in mucous cells of the minor salivary glands in oral cavity and of Brunner's glands in the duodenum. These results suggested that rat SLAMP plays a specific role in the early secretory pathway of glycoproteins in specific types of mucous cells.     

Effect of Salicylic Acid Formulations on Induced Plant Defense against Cassava Anthracnose Disease

This study was to investigate defense mechanisms on cassava induced by salicylic acid formulation (SA) against anthracnose disease. Our results indicated that the SA could reduce anthracnose severity in cassava plants up to 33.3% under the greenhouse condition. The β-1,3-glucanase and chitinase enzyme activities were significantly increased at 24 hours after inoculation (HAI) and decrease at 48 HAI after Colletotrichum gloeosporioides challenge inoculation, respectively, for cassava treated with SA formulation. Synchrotron radiation–based Fourier-transform infrared microspectroscopy spectra revealed changes of the C=H stretching vibration (3,000–2,800 cm⁻¹), pectin (1,740–1,700 cm⁻¹), amide I protein (1,700–1,600 cm⁻¹), amide II protein (1,600–1,500 cm⁻¹), lignin (1,515 cm⁻¹) as well as mainly C–O–C of polysaccharides (1,300–1,100 cm⁻¹) in the leaf epidermal and mesophyll tissues treated with SA formulations, compared to those treated with fungicide carbendazim and distilled water after the challenged inoculation with C. gloeosporioides. The results indicate that biochemical changes in cassava leaf treated with SA played an important role in the enhancement of structural and chemical defense mechanisms leading to reduced anthracnose severity.     

Effects of metal ion and solute conformation change on hydration of small amino acid

The effects of metal ion and solute conformation change on the structures, energetic and dynamics of water molecules in the first hydration shell of amino acid were studied, using three forms of alanine (Ala) and Li(+)/Ala as model molecules. The theoretical investigations were started with construction of the test-particle model (T-model) potentials for all molecules involved and followed by molecular dynamics (MD) simulations of [Ala](aq) and [Li(+)/Ala](aq) at 298 K. The MD results showed that the hydrogen bond (H-bond) networks of water at the functional groups of Ala are strengthened by the metal ion binding, whereas the rotation of the N-C(alpha) bond from the angle phi=0 degrees to 180 degrees brings about smaller effects which cannot be generalized. It was also shown that the dynamics of water molecule in the first hydration shell of amino acid could be estimated from the total-average potential energy landscapes and the water exchange diagrams. The MD results suggested inclusion of an additional dynamic step in the water exchange process, in which water molecule moves inside a channel within the first hydration shell of solute, before leaving the channel at some point. The theoretical results reported in the present work iterated the necessity to include explicit water molecules in the model calculations.     

Priming,signaling, and protein production associated with induced resistance by <Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis> KPS46

Bacillus amyloliquefaciens KPS46 is a rhizobacterium that induces systemic protection in soybean (Glycine max L.) against several diseases and enhances plant growth. In this study, treatment of soybean seed with KPS46 provided protection to leaves from bacterial pustule, caused by Xanthomonas axonopodis pv. glycines (Xag). KPS46 treatment also increased phenolic content and β-1,3-glucanase and peroxidase activity levels in leaves over non-treated plants. Differential expression of these traits was more rapid and pronounced when KPS46 treated plants were infected with Xag, this pattern indicating priming. Also associated with induced resistance by KPS46 was increased production of salicylic acid (SA) and jasmonic acid (JA) in soybean leaves, suggesting both SA- and JA-dependent signaling pathways are systemically triggered by KPS46 seed treatment. When KPS46 was applied to Arabidopsis roots, however, resistance against Pseudomonas syringae pv. tomato (Pst) was induced only in host genotypes with intact jasmonate, ethylene, and auxin sensitivity. Thus, induced resistance against Pst by KPS46 was SA independent and JA/ethylene dependent. Proteins induced in soybean leaves by KPS46 seed treatment and by the seed treatment in combination with pathogen inoculation were determined by proteomic analysis. Among 20 proteins upregulated in KPS46-treated plants, compared with non-treated plants, only three were defense related. In plants that received both KPS46 treatment and inoculation with Xag, nine of the 20 upregulated protein, as compared with proteins produced Xag inoculated plants having no KPS46 treatment, were defense related. This pattern of increased induction of defense-related proteins following pathogen infection of KPS46 treated plants supported priming by KPS46. Aside from proteins with defense-related function, most of the proteins induced by KPS46 were involved in metabolism and energy conversion, reflecting the strong direct positive effect that KPS46 has on soybean growth.     

Morphological and molecular identification of Colletotrichum species associated with cassava anthracnose in Thailand

The objective of this study was to identify the causal agent of anthracnose disease of cassava in Thailand. The study was carried out by collecting cassava samples with anthracnose symptoms from various planting areas including 10 districts of eight provinces in Thailand. One hundred and thirty‐six Colletotrichum samples were isolated from cassava anthracnose lesions on leaves, petioles and stems. Thirty‐eight single‐spore isolates were subsequently obtained and cultured on half potato dextrose agar for morphological and molecular characterizations. All 38 isolates were pathogenic with varying degrees of virulence when tested on detached leaves of Kasetsart 50, a susceptible cassava cultivar. Based on their growth habit, colony morphology, conidial morphology and the internal transcribed spacer sequences similarity to that of Colletotrichum accessions in the GenBank, one isolate was identified as C. capsici, one as C. lindemuthianum, two as C. aeschynomene, four as C. boninense and 28 C. gloeosporioides species complex. Geographically, the cosmopolitan C. gloeosporioides species complex was found in all regions, but other species were found only in particular regions. This is, so far, the first report of Colletotrichum complex species associated with cassava anthracnose in Thailand.