Scholarly Work - Plant Sciences & Plant Pathology
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/8870
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Item Enhanced Rice Growth is Conferred by Increased Leaf ADP-Glucose Pyrophosphorylase Activity(2014-10) Schlosser, Alanna J.; Martin, John M.; Beecher, Brian S.; Giroux, Michael J.Modification of leaf starch levels may be employed in attempts to increase cereal yield. Few studies have examined leaf starch as a plant biomass limiting factor. Here we test the hypothesis that rice plant productivity may be increased by increasing leaf starch. Starch biosynthesis is controlled by the heterotetrameric rate-limiting enzyme ADP-glucose pyrophosphorylase (AGPase). Rice variety Nipponbare was transformed with a modified form of the maize endosperm AGPase large subunit gene, Sh2r6hs, as well as with the small subunit gene, Bt2, under control of a rice RuBisCO small subunit promoter. RNA sequencing results indicated that Sh2r6hs and Bt2 transcript levels were each greater than 20 times that of the native genes. Increased total AGPase activity was correlated with higher leaf starch accumulation at the end of the day. Yield trials of T1 derived homozygous plants indicate that increased leaf AGPase leads to a 29% increase in plant biomass under the conditions tested without changing the rate of photosynthesis while significantly reducing leaf transpiration and conductance. Additionally, functional annotation clustering of significantly up and down regulated transcripts reveals areas of protein metabolism, specifically protein biosynthesis, transport, and localization, that were altered in response to increased leaf starch. Together, these findings indicate plant growth is limited by native levels of leaf starch and that it is possible to increase plant yield via the starch biosynthesis pathway.Item 3-Carbamoylquinoxalin-1-ium chloride(2011-12) Harper, James K.; Strobel, Gary A.; Arif, Atta M.The title compound, C9H8N3O+·Cl-, was isolated from a liquid culture of streptomyces sp. In the cation, the ring system makes a dihedral angle of 0.2 (2)° with the amide group. The protonation creating the cation occurs at ome of the N atoms in the quinoxaline ring system. In the crystal, the ions are linked through N-H...O and N-H...Cl hydrogen bonds, forming a two-dimensional network parallel to (10\overline{3}).Item Evaluation of cellulose as a substrate for hydrocarbon fuel production by Ascocoryne sarcoides (NRRL 50072)(2014-02) Mallette, Natasha D.; Pankrantz, E. M.; Busse, S.; Strobel, Gary A.; Carlson, Ross P.; Peyton, Brent M.The fungal endophyte, Ascocoryne sarcoides, produced aviation, gasoline and diesel-relevant hydrocarbons when grown on multiple substrates including cellulose as the sole carbon source. Substrate, growth stage, culturing pH, temperature and medium composition were statistically significant factors for the type and quantity of hydrocarbons produced. Gasoline range (C5-C12), aviation range (C8-C16) and diesel range (C9-C36) organics were detected in all cultured media. Numerous non-oxygenated hydrocarbons were produced such as isopentane, 3,3-dimethyl hexane and d-limonene during exponential growth phase. Growth on cellulose at 23˚C and pH 5.8 produced the highest overall yield of fuel range organics (105 mg * g·biomass−1). A change in metabolism was seen in late stationary phase from catabolism of cellulose to potential oxidation of hydrocarbons resulting in the production of more oxygenated compounds with longer carbon chain length and fewer fuel-related compounds. The results outline rational strategies for controlling the composition of the fuel-like compounds by changing culturing parameters.