Steven E Screen

The present invention relates to a corn plant and seed with enhanced levels of protein and amino acids. The invention also relates to DNA constructs that provide expression in transgenic corn cells of an asparagine synthetase enzyme. The DNA constructs are used in a method to produce transgenic corn plants and seeds and to select for plants and see...

Crop yield is a highly complex quantitative trait. Historically, successful breeding for improved grain yield has led to crop plants with improved source capacity, altered plant architecture, and increased resistance to abiotic and biotic stresses. To date, transgenic approaches towards improving crop grain yield have primarily focused on protectin...

Gene expression data for overexpression and miRNA targets described in this manuscript. (XLSX)

The single B-box clade in Arabidopsis thailana and Glycine max. The Arabidopsis thaliana genome contains seven single B-box domain genes while the paleopolyploid Glycine max genome contains thirteen single B-box genes. Phylogenetic analysis indicates that GmBBX52 and GmBBX53 are orthologs of the Arabidopsis thaliana BBX32 gene. (TIFF)

Overexpression of GmBBX52 (line 7) or GmBBX53 (line 2) in soybean affects the transcript abundance of central clock components near ZT 0. Levels of both central clock components GmLCL2 (A) and GmTOC1 (B) were assayed by quantigene RNA extraction and expression analysis from V2 leaf tissue harvested from soybean plants grown in a controlled environm...

Commercial varieties used in this study. (XLSX)

Changes observed in clock gene expression in the microarray experiment. (XLSX)

Phylogenetic analysis of the entire A. thaliana and G. max B-box gene family. (TIFF)

Primers used to quantitate transgene expression in this study. (XLSX)

BBX ID and the public gene IDs of the Arabidopsis and Soy Bbox genes described within the manuscript. (XLSX)

Maize (Zea mays) oil has high value but is only about 4% of the grain by weight. To increase kernel oil content, fungal diacylglycerol acyltransferase2 (DGAT2) genes from Umbelopsis (formerly Mortierella) ramanniana and Neurospora crassa were introduced into maize using an embryo-enhanced promoter. The protein encoded by the N. crassa gene was long...

Four distinct full-length cDNA clones encoding asparagine synthetase (AS; EC 6.3.5.4) were isolated from maize (Zea mays). Detailed analysis of two these genes suggested the previously published maize AsnS gene (gi 984262) is possibly a chimera. In silico analysis identified additional members of this new monocot-specific class in rice genomic DNA...

Fungi secrete subtilisin proteinases to acquire nutrients and breach host barriers. Here we sought a global characterization of the diversity of subtilisins in the insect pathogen Metarhizium anisopliae. Expressed sequence tag (EST) analyses showed that a broad host range strain of M. anisopliae sf. anisopliae (strain 2575) expressed 11 subtilisins...

Conidiobolus coronatus (Zygomycota) is a facultative saprobe that is a pathogen of many insect species. Almost 2000 expressed sequence tag (EST) cDNA clones were sequenced to analyse gene expression during growth on insect cuticle. Sixty percent of the ESTs that could be clustered into functional groups (E<or=10(-5)) had their best BLAST hits among...

Expressed sequence tag (EST) libraries for Metarhizium anisopliae, the causative agent of green muscardine disease, were developed from the broad host-range pathogen Metarhizium anisopliae sf. anisopliae and the specific grasshopper pathogen, M. anisopliae sf. acridum. Approximately 1,700 5' end sequences from each subspecies were generated from cD...

Extracellular chitinase activity has been implicated in the pathogenesis of several fungal infections. Following induction with chitin, the insect pathogens Metarhizium anisopliae sf. acridum ARSEF strain 324 and Metarhizium anisopliae sf. anisopliae ARSEF strain 2575 secrete 44-kDa basic and acidic isoforms of endochitinase, respectively. The gene...

Unlike trypsins, chymotrypsins have not until now been found in fungi. Expressed sequence tag analysis of the deuteromycete Metarhizium anisopliae identified two trypsins (family S1) and a novel chymotrypsin (CHY1). CHY1 resembles actinomycete (bacterial) chymotrypsins (family S2) rather than other eukaryote enzymes (family S1) in being synthesized...

Aspergillus fumigatus is saprotrophic with an unusual ability to colonize the respiratory tract. The mechanisms that permit pathogenicity may have evolved to adapt the fungus to life as a saprobe. To define the nature of these adaptations and identify common themes in fungal pathogenesis to vertebrates, insects and plants, we compared A. fumigatus...

Aspergillus spp. cause disease in a broad range of organisms, but it is unknown if strains are specialized for particular hosts. We evaluated isolates of Aspergillus flavus,Aspergillus fumigatus, and Aspergillus nidulansfor their ability to infect bean leaves, corn kernels, and insects (Galleria mellonella). Strains of A. flavus did not affect nonw...

Ambient pH regulates the expression of virulence genes of Metarhizium anisopliae, but it was unknown if M. anisopliae can regulate ambient pH. Mutants of M. anisopliae altered in production of oxalic acid were evaluated for the interrelationship of ambient pH, buffering capacity added to media, growth, and generation of extracellular proteases and...

Attempts to improve the effectiveness of entomopathogenic fungi as biological control agents require a clear understanding of the pathogenicity determinants at both the biochemical and molecular level. Proteases play a key role in entomopathogenicity, allowing the fungus to penetrate the insect cuticle and rapidly invade the host. The most extensiv...

The pr1 gene of the entomopathogenic fungus Metarhizium anisopliae encodes a serine protease that is highly active towards the insect cuticle and whose synthesis is subject to both carbon and nitrogen repression. The pr1 promoter region was sequenced revealing the presence of putative CREA- and AREA-binding sites. In vitro bandshift experiments dem...

Metarhizium anisophilae (Ma) secretes a range of proteases when grown in vitro on insect cuticle. A trypsin-like serine protease, PR2, was purified from culture filtrates by anion exchange chromatography and the N-terminal sequence determined. Using oligodeoxyribonucleotide probes based on this sequence and that of the highly conserved trypsin acti...

The NIFA protein from Rhizobium leguminosarum biovar trifolii (R. trifolii) strain ANU843 lacks an N-terminal domain present in homologous NIFA proteins from other diazotrophs. The R. trifolii nifA gene product is unstable when expressed in Escherichia coli under both aerobic and microaerobic conditions. Stability is increased by fusion of addition...