CarbBank: A Structural and Bibliographic Data Base. Progress Report

An IBM PC-compatible computerized database (CCSD, Complex Carbohydrate Structure Database) and database management system (CarbBank) for complex carbohydrates were created to provide a structure and citation information system to meet the needs of persons interested in carbohydrate science. The CarbBank staff will enter new structures into the database and correct present entries, under the guidance of approximately forty CarbBank curators. The CCSD has approximately 1400 records and is being verified by the curators at the present time, May 1989. We plan to have the database commercially available in September 1989, and we foresee a database containing about 10,000 records within three years. The CCSD exists as a flat file database. We propose to change a relational database format over the next two years to accommodate the large number of entries expected, to facilitate database maintenance, and to support a functional integration of data types, such as three-dimensional information, not presently included in the CCSD. We propose to develop CarbBank for other computer platforms and to enhance the features available in CarbBank

Structures and functions of oligosaccharins. Progress report, June 15, 1993--March 14, 1995

This research focuses on the following: Purification, characterization, and cell wall localization of an {alpha}-fucosidase that inactivates a xyloglucan oligosaccharin; Oligogalacturonides inhibit the formation of roots on tobacco explants; Activation of a tobacco glycine-rich protein gene by a fungal glucan preparation; Fusarium moniliforme secretes four endopolygalacturonases derived from a single gene product; Polygalacturonase-inhibiting protein accumulates in Phaseolus vulgaris L. in response to wounding, elicitors and fungal infection; Generation of {beta}-glucan elicitors by plant enzymes and inhibition of the enzymes by a fungal protein; Polygalacturonase inhibitor proteins from bean (Phaseolus vulgaris L.), pear (Pyrus communis L.) and tomato (Lycopersicon esculentum): Immunological relatedness and specificity of polygalacturonase inhibition; Fungi protect themselves against plant pathogenesis-related glycanases; Purification, cloning, and characterization of two xylanases from Magnaporthe grisea, the rice blast fungus; and Molecular cloning and expression pattern of an {alpha}-fucosidase gene from pea seedlings

Dynamics of intracellular mannan and cell wall folding in the drought responses of succulent <i>Aloe</i> species

Plants have evolved a multitude of adaptations to survive extreme conditions. Succulent plants have the capacity to tolerate periodically dry environments, due to their ability to retain water in a specialized tissue, termed hydrenchyma. Cell wall polysaccharides are important components of water storage in hydrenchyma cells. However, the role of the cell wall and its polysaccharide composition in relation to drought resistance of succulent plants are unknown. We investigate the drought response of leaf-succulent Aloe (Asphodelaceae) species using a combination of histological microscopy, quantification of water content, and comprehensive microarray polymer profiling. We observed a previously unreported mode of polysaccharide and cell wall structural dynamics triggered by water shortage. Microscopical analysis of the hydrenchyma cell walls revealed highly regular folding patterns indicative of predetermined cell wall mechanics in the remobilization of stored water and the possible role of homogalacturonan in this process. The in situ distribution of mannans in distinct intracellular compartments during drought, for storage, and apparent upregulation of pectins, imparting flexibility to the cell wall, facilitate elaborate cell wall folding during drought stress. We conclude that cell wall polysaccharide composition plays an important role in water storage and drought response in Aloe

Developmental features of cotton fibre middle lamellae in relation to cell adhesion and cell detachment in cultivars with distinct fibre qualities.

Background: Cotton fibre quality traits such as fibre length, strength, and degree of maturation are determined by genotype and environment during the sequential phases of cotton fibre development (cell elongation, transition to secondary cell wall construction and cellulose deposition). The cotton fibre middle lamella (CFML) is crucial for both cell adhesion and detachment processes occurring during fibre development. To explore the relationship between fibre quality and the pace at which cotton fibres develop, a structural and compositional analysis of the CFML was carried out in several cultivars with different fibre properties belonging to four commercial species: Gossypium hirsutum, G. barbadense, G. herbaceum and G. arboreum. Results: Cotton fibre cell adhesion, through the cotton fibre middle lamella (CFML), is a developmentally regulated process determined by genotype. The CFML is composed of de-esterified homogalacturonan, xyloglucan and arabinan in all four fibre-producing cotton species: G. hirsutum, G. barbadense, G. herbaceum and G. arboreum. Conspicuous paired cell wall bulges are a feature of the CFML of two G. hirsutum cultivars from the onset of fibre cell wall detachment to the start of secondary cell wall deposition. Xyloglucan is abundant in the cell wall bulges and in later stages pectic arabinan is absent from these regions. Conclusions: The CFML of cotton fibres is re-structured during the transition phase. Paired cell wall bulges, rich in xyloglucan, are significantly more evident in the G. hirsutum cultivars than in other cotton species