Effects of medicinal herbs "Plantago asiatica", "Houttuynia cordata" and "Mentha haplocalyx" on non-specific immune responses of cobia (Rachycentron canadum).

This study investigated the effects of orally administered Plantago asiatica, Houttuynia cordata, and Mentha haplocalyx on the growth and nonspecific immune responses of cobia (Rachycentron canadum). The nonspecific immune parameters assessed were weight gain, feed conversion ratio, superoxide anion (O) production, superoxide dismutase (SOD) activity, phagocytic rate, phagocytic index, lysozyme activity, serum albumin and globulin, and albumin:globulin (A/G) ratio. The growth experiment indicated that 6-week dietary treatments did not significantly affect on the growth of cobia.

Resistance to Cucumber mosaic virus in Gladiolus plants transformed with either a defective replicase or coat protein subgroup II gene from Cucumber mosaic virus.

Transgenic Gladiolus plants that contain either Cucumber mosaic virus (CMV) subgroup I coat protein, CMV subgroup II coat protein, CMV replicase, a combination of the CMV subgroups I and II coat proteins, or a combination of the CMV subgroup II coat protein and replicase genes were developed. These plants were multiplied in vitro and challenged with purified CMV isolated from Gladiolus using a hand-held gene gun. Three out of 19 independently transformed plants expressing the replicase gene under control of the duplicated CaMV 35S promoter were found to be resistant to CMV subgroup I.

Foci of stagonospora nodorum blotch in winter wheat before canopy development.

ABSTRACT Stagonospora nodorum blotch (SNB) often develops explosively on upper leaves and glumes of wheat. Inoculum for late season infections may arise from early disease foci in the lower canopy or from recent immigration of wind-dispersed ascospores. Research was conducted to determine if foci of SNB are present and secondary spread has occurred in fields before tiller elongation.

Diversity of the trifunctional histidine biosynthesis gene (his) in cereal Phaeosphaeria species.

Phaeosphaeria species are important causal agents of Stagonospora leaf blotch diseases in cereals. In this study, the nucleotide sequence and deduced polypeptide of the trifunctional histidine biosynthesis gene (his) are used to investigate the phylogenetic relationships and provide molecular identification among cereal Phaeosphaeria species. The full-length sequences of the his gene were obtained by PCR amplification and compared among cereal Phaeosphaeria species.

The Cercospora nicotianae gene encoding dual O-methyltransferase and FAD-dependent monooxygenase domains mediates cercosporin toxin biosynthesis.

Cercosporin, a photo-activated, non-host-selective phytotoxin produced by many species of the plant pathogenic fungus Cercospora, causes peroxidation of plant cell membranes by generating reactive oxygen species and is an important virulence determinant. Here we report a new gene, CTB3 that is involved in cercosporin biosynthesis in Cercospora nicotianae. CTB3 is adjacent to a previously identified CTB1 encoding a polyketide synthase which is also required for cercosporin production.

RNA polymerase II gene (RPB2) encoding the second largest protein subunit in Phaeosphaeria nodorum and P. avenaria.

A 5586 bp sequence (accession no. DQ278491), which includes the RNA polymerase II gene (RPB2) encoding the second largest protein subunit (RPB2), was obtained from the wheat biotype Phaeosphaeria nodorum (PN-w) by PCR amplification. The 3841 bp full length RPB2 gene contains two exons and a 52 bp intron, and encodes a complete 1262 amino acid protein.

A New Biotype of Phaeosphaeria sp. of Uncertain Affinity Causing Stagonospora Leaf Blotch Disease in Cereals in Poland.

A new Phaeosphaeria sp. biotype was isolated from winter ryes in Poland during 1995. Two isolates, Sn23-1 and Sn48-1, were obtained from diseased leaves of cvs.

Sequence diversity of beta-tubulin (tubA) gene in Phaeosphaeria nodorum and P. avenaria.

Full-length coding sequences of the beta-tubulin gene (tubA) were PCR-amplified and sequenced from 42 Phaeosphaeria isolates, including 16 P. nodorum and 23 P. avenaria species from cereals, two Polish isolates from rye (Secale cereale L.

The CTB1 gene encoding a fungal polyketide synthase is required for cercosporin biosynthesis and fungal virulence of Cercospora nicotianae.

Cercosporin is a light-activated, non-host-selective toxin produced by many Cercospora fungal species. In this study, a polyketide synthase gene (CTB1) was functionally identified and molecularly characterized to play a key role in cercosporin biosynthesis by Cercospora nicotianae. We also provide conclusive evidence to confirm the crucial role of cercosporin in fungal pathogenesis.

Induction of phytohormones and differential gene expression in citrus flowers infected by the fungus Colletotrichum acutatum.

Colletotrichum acutatum infects citrus petals and induces premature fruit drop and the formation of persistent calyces. The accumulation of hormones and other growth regulators, and differential gene expression in affected flowers and young fruit, was examined following fungal infection. Ethylene evolution increased threefold and indole-3-acetic acid (IAA) accumulation was as much as 140 times.

Indole derivatives produced by the fungus Colletotrichum acutatum causing lime anthracnose and postbloom fruit drop of citrus.

Postbloom fruit drop (PFD) of citrus and Key lime anthracnose (KLA) are caused by Colletotrichum acutatum. Both fungal isolates can infect flower petals, induce young fruit abscission and result in severe yield loss on many citrus cultivars. Previous studies revealed that infection of citrus flowers by C.

QTL mapping of partial resistance in winter wheat to Stagonospora nodorum blotch.

Stagonospora nodorum blotch is an important foliar and glume disease in cereals. Inheritance of resistance in wheat appears to be quantitative. To date, breeding of partially resistant cultivars has been the only effective way to combat this pathogen.

Sequence diversity of mating-type genes in Phaeosphaeria avenaria.

Phaeosphaeria avenaria, one of the causal agents of stagonospora leaf blotch diseases in cereals, is composed of two subspecies, P. avenaria f. sp.

TAXONOMY AND IDENTIFICATION OF SEPTORIA AND STAGONOSPORA SPECIES ON SMALL-GRAIN CEREALS.

Numerous significant changes have been made in the taxonomy of both the anamorphs and teleomorphs of the Septoria group of leaf spot pathogens on small grain cereals during the past 30 years. The pathogens fall into two related but distinct groups, with anamorphic genera now placed in Septoria and Stagonospora of the Sphaeropsidales. Each of these genera has distinct teleomorphs in the Loculoascomycetes in Mycosphaerella and Phaeosphaeria.

Molecular analyses of a repetitive DNA sequence in wheat (Triticum aestivum L.).

A repetitive sequence designated WE35 was isolated from wheat genomic DNA. This sequence consists of a 320-bp repeat unit and represents approximately 0.002% of the total wheat DNA.

Isolation of a zeta class wheat glutathione S-transferase gene.

A new Zeta class glutathione S-transferases (GST) gene, pGST, has been cloned from wheat for the first time by the differential display PCR (DD-PCR) method. The genomic sequence of pGST, TA-GSTZ1, contains nine exons that encode a polypeptide of 213 amino acids and eight introns. The deduced amino acid sequence of TA-GSTZ1 as well as the exon:intron placement are more similar to the GSTs of the Zeta class than to the two wheat GSTs reported earlier.

Isolation of two differentially expressed wheat ACC synthase cDNAs and the characterization of one of their genes with root-predominant expression.

Two partial 1-aminocyclopropane-1-carboxylic acid (ACC) synthase cDNA clones (pWAS1, 1089 bp; and pWAS3, 779 bp) were isolated by polymerase chain reaction (PCR) using cDNA to total mRNA purified from etiolated wheat seedlings as template and degenerate oligonucleotides synthesized based on the regions of the ACC synthase amino acid sequence that are highly conserved among different plants. Northern analysis showed that the expression of the corresponding genes are differentially regulated. While the transcripts of pWAS1 were found in all the tissues of wheat that were tested with a maximum level at the early stages of spike development, pWAS3 mRNA was present almost exclusively in the root.

Nucleotide sequence analysis of the genomes of the MAV-PS1 and P-PAV isolates of barley yellow dwarf virus.

The MAV-PS1 and P-PAV isolates of barley yellow dwarf virus (BYDV) are serologically related, but not identical. Both are transmitted by the aphid Macrosiphum avenae, but P-PAV is also transmitted by Rhopalosiphum padi. To evaluate the basis for these and other differences, overlapping clones from cDNA libraries representing the genome of each isolate were characterized by restriction enzyme digestion and by hybridization, and subsequently sequenced.

Nucleotide sequences of coat protein genes for three isolates of barley yellow dwarf virus and their relationships to other luteovirus coat protein sequences.

Barley yellow dwarf virus (BYDV) can be separated into two groups based on, among other criteria, serological relationships that are presumably governed by the viral capsid structure. Nucleotide sequences for the coding regions of coat proteins of approximately 22 K were identified for the MAV-PS1, P-PAV (group 1) and NY-RPV (group 2) isolates of BYDV. The MAV-PS1 and P-PAV coat protein sequences shared 71% deduced amino acid similarity whereas that of the NY-RPV isolate shared no more than 51% similarity with either the MAV-PS1 or the P-PAV sequence.

Expression of a maize storage protein gene in petunia plants is not restricted to seeds.

Genes encoding maize seed storage proteins, zeins, are expressed in developing endosperm tissue. To determine whether the DNA sequences controlling the developmental expression of these genes are recognized in dicots, we introduced a gene encoding a M(r) 19,000 zein protein into petunia by Agrobacterium tumefaciens mediated transformation. Southern blot analysis of DNA from regenerated transgenic plants showed that between 1 and 12 copies of the zein gene were integrated at various locations in the petunia genome.

Conversion of pentoses by yeasts.

The utilization and conversion of D-xylose, D-xylulose, L-arabinose, and xylitol by yeast strains have been investigated with the following results: (1) The majority of yeasts tested utilize D-xylose and produce polyols, ethanol, and organic acids. The type and amount of products formed varies with the yeast strains used. The most commonly detected product is xylitol.

Sequential utilization of mixed monosaccharides by yeasts.

Four yeasts (Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida utilus, and Rhodotorula toruloides) were tested for their ability to grow and consume D-glucose, D-xylose, D-xylulose, and D-xylitol. Sequential utilization of substrates was observed when D-glucose as mixed with D-xylulose as the carbon source. Catabolite inhibition was tentatively concluded to be responsible for this regulatory mechanism.

Enzymatic and Microbial Preparation of d-Xylulose from d-Xylose.

A high-d-xylulose mixture (d-xylose-d-xylulose = 33:67) was prepared from the cold ethanol extract of preisomerized d-xylose solution (d-xylose-d-xylulose = 77:23). Fusarium oxysporum f. sp.