Washington State University

About: Washington State University is a education organization based out in Pullman, Washington, United States. It is known for research contribution in the topics: Population & Gene. The organization has 26947 authors who have published 57736 publications receiving 2341509 citations. The organization is also known as: WSU & Wazzu.

Contribution of phenazine antibiotic biosynthesis to the ecological competence of fluorescent pseudomonads in soil habitats.

Abstract: Phenazine antibiotics produced by Pseudomonas fluorescens 2-79 and Pseudomonas aureofaciens 30-84, previously shown to be the principal factors enabling these bacteria to suppress take-all of wheat caused by Gaeumannomyces graminis var. tritici, also contribute to the ecological competence of these strains in soil and in the rhizosphere of wheat. Strains 2-79 and 30-84, their Tn5 mutants defective in phenazine production (Phz-), or the mutant strains genetically restored for phenazine production (Phz+) were introduced into Thatuna silt loam (TSL) or TSL amended with G. graminis var. tritici. Soils were planted with three or five successive 20-day plant-harvest cycles of wheat. Population sizes of Phz- derivatives declined more rapidly than did population sizes of the corresponding parental or restored Phz+ strains. Antibiotic biosynthesis was particularly critical to survival of these strains during the fourth and fifth cycles of wheat in the presence of G. graminis var. tritici and during all five cycles of wheat in the absence of take-all. In pasteurized TSL, a Phz- derivative of strain 30-84 colonized the rhizosphere of wheat to the same extent that the parental strain did. The results indicate that production of phenazine antibiotics by strains 2-79 and 30-84 can contribute to the ecological competence of these strains and that the reduced survival of the Phz- strains is due to a diminished ability to compete with the resident microflora.

The sheep genome illuminates biology of the rumen and lipid metabolism

Abstract: Sheep (Ovis aries) are a major source of meat, milk, and fiber in the form of wool and represent a distinct class of animals that have a specialized digestive organ, the rumen, that carries out the initial digestion of plant material. We have developed and analyzed a high-quality reference sheep genome and transcriptomes from 40 different tissues. We identified highly expressed genes encoding keratin cross-linking proteins associated with rumen evolution. We also identified genes involved in lipid metabolism that had been amplified and/or had altered tissue expression patterns. This may be in response to changes in the barrier lipids of the skin, an interaction between lipid metabolism and wool synthesis, and an increased role of volatile fatty acids in ruminants compared with nonruminant animals.

Defensive resin biosynthesis in conifers

Abstract: Tree killing bark beetles and their vectored fungal pathogens are the most destructive agents of conifer forests worldwide. Conifers defend against attack by the constitutive and inducible production of oleoresin, a complex mixture of mono-, sesqui-, and diterpenoids that accumulates at the wound site to kill invaders and both flush and seal the injury. Although toxic to the bark beetle and fungal pathogen, oleoresin also plays a central role in the chemical ecology of these boring insects, from host selection to pheromone signaling and tritrophic level interactions. The biochemistry of oleoresin terpenoids is reviewed, and the regulation of production of this unusual plant secretion is described in the context of bark beetle infestation dynamics with respect to the function of the turpentine and rosin components. Recent advances in the molecular genetics of terpenoid biosynthesis provide evidence for the evolutionary origins of oleoresin and permit consideration of genetic engineering strategies to improve conifer defenses as a component of modern forest biotechnology.

RALF, a 5-kDa ubiquitous polypeptide in plants, arrests root growth and development.

Abstract: A 5-kDa polypeptide was isolated from tobacco leaves that induced a rapid alkalinization of the culture medium of tobacco suspension-cultured cells and a concomitant activation of an intracellular mitogen-activated protein kinase. An N-terminal sequence was obtained, and a cDNA coding for the 49-aa polypeptide was isolated from a tobacco cDNA library. The cDNA encoded a preproprotein of 115 amino acids that contained the polypeptide at its C terminus. A search among known expressed sequence tags revealed that genes encoding Rapid ALkalinization Factor (RALF) preproproteins were present in various tissues and organs from 16 species of plants representing 9 families. A tomato homolog of the polypeptide was synthesized and, when supplied to germinating tomato and Arabidopsis seeds, it caused an arrest of root growth and development. Although its specific role in growth has not been established, the polypeptide joins the ranks of the increasing number of polypeptide hormones that are known to regulate plant stress, growth, and development.