The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center [report]

P. Albersheim, A. Darvill
1991 unpublished
Paye 4 thru 7 intentiona]]y omitted OVERVIEW The ComplexCarbohydrate ResearchCenter (CCRC) was establishedin September 1985. In 1987, the CCRC ""as awarded a three-agency Plant Science Center grant for the study of the carbohydrates of plants and of microbes that interact with plants. This three-agency Plant Science Center grant has been of the utmost importance to the success of the CCRC and is, indeed, the backbone that holds tt;e CCRC together. During the first four years of funding, the
more » ... of funding, the Plant Science Center grant has supported the core of the CCRC, including personnel and the operation and maintenance of equipment. Without this funding, in ali likelihood the CCRC would probably collapse. The Plant Science Center grant funds are used to support basic research in carbohydrate science; training of graduate students, postdoctoral research associates, and visiting scientists; collaborative carbohydrate research projects with other institutions; service for carbohydrate analyses to other institutions; and a two.week training course for members of the scientific community in the methods used to analyze complex carbohydrates. We are particularly proud of the diversity of the carbohydrate science supported by this grant. The subjects extend from oligosaccharides that protect plants against viruses to oligosaccharides that induce explants to flower, from receptors for oligosaccharides that elicit phytoalexins to oligosaccharides that regulate ion transport across plasma membranes, from the structures of pectic and hemicellulosic polysaccharides to the ability of patl_ogenesis-relatedenzymes to release phytoalexin elicitors from fungal cell walls, from the cloning of carbohydrate-degrading enzymes to the cloning of glycanase inhibitors, from the identification of oligosaccharides that kill plant cells to the cloning of receptors that perceive those oligosaccharides that inhibit root formation and stimulate flower formation, from characterization of bacterial polysaccharides that have useful physical characteristics to characterization of complex carbohydrates involved in Rhizobium symbioses, and from developing analyt;cal methods to purify and characterize carbohydrates to the development of computer methods to reduce the time needed to structurally characterize carbohydrates. This diversity is enabled by the interplay of expertise that is possible in a center environment. . 1990. Expression of Rhizobium leguminosarurn CFN42 genes for IIpopolysaccharlde In strains derived from different R. legumlnosarum soil Isolates. J. BacterloL 172:.548-555. Two mutant derivatives of Rhizobium leguminosarum ANU843 defective in lipopolysaccharide(LPS) were isolated. The LPSsof both mutantslacked O antigen and some sugar residues of the LPS core oligosaccharides. Genetic regions previouslycloned from another Rhizobium leguminosarum wild-type isolate,strain CFN42, were used to complement these mutants. One mutant was complemented to give LPS that was apparently identicaJto the LPS strain ANU843 in antigenicity, electrophoreticmobility, and sugar composition. The other mutant was complemented by a second CFN42/ps genetic region, in this case, the resulting LPS contained O-antigen sugars characteristicof donor strain CFN42 and reacted weakly with antiserum against CFN42 cells, but did not react detectab_ with antiserum against ANU843 cells. Therefore, one of the CFN42 Ips genetic regions specifies a function that is conserved between the two R. leguminosarum wild-type isolates, whereas the other region, at least in part, specifies a strain-specific LPS structure. Transter of these two genetic regions into wiid-_ strains derived from R. leguminosarum ANU843 and 128C53 gave results consistent with this conclusion. The mutants derived from strain ANU843 elicited incompletely developed clover nodules that exhibited low bacterial populations and very low nitrogenase activity. Both mutants elicited normally developed, nitrogen-fixing clover nodules when they carded CFN42 /ps DNA that permitted synthesis of O-antigen-containing LPS, regardless of whether the O antigen was the one originally made by strain ANU843. Bhat, U.R., H. Mayer, A. Yokota, R.I. Holllngsworth, and R.W. Carlson. 1991. Occurrence of lipid A variants with 27-hydroxyoctacosanol¢ acid In lipopolysaccharides from the Rhlzoblaceae group. J. Bacterlol. 173:2155-2159. Upopolysaccharides (LPS_) isolated from several strains of Rhizobium, Bradyrhizobium, Agrobacterium, and Azorhizebiur_l were screened for the presence of 27-hydroxyoctacos2noic acid. The LPSs from ali strains, with the exception of Azorhizobium caulinodans, contained various amounts of this long-chain hydroxy fatty acid in the lipid A fractions. Analysis of the lipid A sugars revealed three types of backbones: those containing glucosamine (as found in Rhizobium meliloti and Rhizobium fredii), those containing glucosamine and galacturonic acid (as found in Rhizobium leguminosarum by. phaseoli, trifolil, and viciae), and those containing 2,3-diamino-2,3-dideoxyglucose either alone or in combination with glucosamine (as found in Bradyrhizobium japomcum and Bradyrhizobium sp. [Lupinus] strain DSM 30140). The distribution of 27-hydroxyoctacosanoic acid as wel/as analysis of lipid A backbone sugars revealed the taxonomic relatedness of various strains of Rhizobiaceae. t _ , i , Adve_sements for the courses were placed in the following publications: ASPP Bio/Technology
doi:10.2172/5229377 fatcat:elnvh43bo5gddfllcujviuw4ui