HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hill-Ambroz, K. Articles by Fellers, J. P. Search for Related Content PubMed Articles by Hill-Ambroz, K. Articles by Fellers, J. P. Agricola Articles by Hill-Ambroz, K. Articles by Fellers, J. P.

ORIGINAL RESEARCH

Expression Analysis and Physical Mapping of a cDNA Library of Fusarium Head Blight Infected Wheat Spikes

K. Hill-Ambroz, A.R. Matthews, and J.P. Fellers, USDA-ARS Plant Science and Entomology Unit, 4008 Throckmorton Hall, Manhattan, KS 66506. C.A. Webb, USDA-APHIS-PPQ, 4031 Throckmorton Hall, Manhattan, KS 66506. W. Li and B.S. Gill, Dep. of Plant Pathology, Kansas State Univ., Manhattan, KS 66506. K. Hill-Ambroz current address: LI-COR, 4308 Progressive Ave., Lincoln, NE 68504. Joint contribution of the USDA-ARS and the Kansas Agric. Exp. Stn. Journal no. 01-94-J. Mention of a trademark of a proprietary product does not constitute a guarantee of warranty of the product by the USDA, and does not imply its approval to the exclusion of other products that may also be suitable

^* Corresponding author (jpf{at}pseru.ksu.edu).

	ABSTRACT

TOP NOTES ABSTRACT INTRODUCTION Materials and Methods Results Discussion REFERENCES

 
Resistance to Fusarium head blight (FHB) (caused mainly by Fusarium graminearum Schw.) is difficult to obtain because of the quantitative nature and the numerous types of resistance involved. cDNA expression arrays have become a rapidly growing area for the identification and characterization of genes involved in complex pathways. A cDNA library was made from wheat (Triticum aestivum L.) spikes of the variety ‘Sumai 3’, 24 h after inoculation with F. graminearum. Clones were sequenced and putative function assigned to each clone based on BLASTX alignments. Nylon membrane arrays were made from the 580 unigenes present in the library, of which 75 expressed clones were induced in the first 24 h after inoculation. Of these unigenes, 14 are involved in defense response, 9 in gene expression and regulation, 29 in other cell functions, and 24 are without a known function. The induced genes catalyze key steps in the formation of lignin, energy production, and production of phytoalexins suggesting that resistance in wheat to Fusarium is provided by a different pathway than that of the hypersensitive response. Two of the induced genes, BE585589 and BE585627, were physically mapped to regions of chromosomes 3AS and 6BL, respectively, known to contain major QTL for FHB resistance.

	INTRODUCTION

TOP NOTES ABSTRACT INTRODUCTION Materials and Methods Results Discussion REFERENCES

 
FUSARIUM HEAD BLIGHT has become a significant pathogen of both wheat and barley (Hordeum vulgare L.) in the world, including the USA. In 1993, this disease caused US$826 million in crop losses in the USA. (McMullen et al., 1997). The resulting crop damage is due to shriveled grain, poor germination, and contamination with mycotoxins that are toxic to animals and humans (Bai and Shaner, 1994). Finding natural resistance in wheat germplasm has proven elusive. The present levels of resistance in wheat to FHB are quantitative and may be due to either hindering the initial infection or slowing of the spread of the infection (Schroeder and Christensen, 1963). Resistance to FHB is separated into five categories: Type I, resistance to initial infection; Type II, resistance to spread of infection; Type III, resistance to kernel infection; Type IV, tolerance; and Type V, resistance to the mycotoxin deoxynivalenol (DON) (Schroeder and Christensen, 1963; Wang and Miller, 1988; Mesterhazy, 1995). No complete resistance is available, but Type II resistance is common, mostly limited to varieties from China and South America, and may be controlled by up to five minor genes (Singh et al., 1995; Van Ginkel et al., 1996; Bai et al., 2000).

Little is known about the early stages of infection. Fungal colonization of wheat spikes is limited to a window of 10 to 20 d, going from anthesis to the soft dough stage of seed development (Schroeder and Christensen, 1963). The germinated macroconidia of F. graminearum is evident on the surface of glumes 6 to 12 h after inoculation (hai), hyphae at 12 to 24 hai, and conidiophores at 48 to 76 hai (Pritsch et al., 2000). No direct penetration of the glumes is evident, but hyphae within the tissue are observed at 48 to 76 hai (Pritsch et al., 2000). Further investigation with the close relative F. culmorum, W.G. Smith demonstrate that at 48 hai hyphal networks are evident on the inner epidermal surfaces of spikelets, on hairs on the top of the ovary, or on the remaining anthers. However, penetration of the inner surface of the palea and lemma is only observed 48 hai (Kang and Buchenauer, 2000a.). In both of these cases there is no direct evidence for the mode of penetration.

Cytologically there is no evidence supporting a specific recognition by the host or specific point of entry into the host. There is molecular evidence, though, that the host recognizes an infection.

Type II resistance was initially believed to be based on an unknown physiological factor because F. graminearum was observed to grow faster in a susceptible than a resistant wheat cultivar (Schroeder and Christensen, 1963). Pritsch et al. (2000) found no differences in timing or development of symptoms on the glume between resistant and susceptible cultivars. However, cellular differences were evident. Lignin accumulates at a higher rate in resistant cultivar host cells. Deoxynivalenol accumulates more slowly in resistant lines as well (Kang and Buchenauer, 2000b). Cytologically there is no evidence supporting a specific recognition by the host or specific point of entry into the host. There is molecular evidence, though, that the host recognizes an infection. Pritsch et al. (2000) determined that transcripts for the defense response genes peroxidase, PR-1, PR-2, and PR-3 accumulate similarly in both resistant and susceptible cultivars. But, transcripts for PR-4 and PR-5 were significantly higher in resistant cultivars.

The advancement of automated sequence analysis and the use of randomly selected cDNA clones have advanced the understanding of genome expression in many organisms and tissues. End sequencing of cDNAs is sufficient to assign putative function to a given clone through amino acid similarity to other cloned genes. Expression arrays, made of large numbers of expressed sequence tags (ESTs), provide a global view of cell responses to defined stimuli. In wheat, genomics and gene expression were limited to ESTs because of its large genome size of 16.0 x 10⁹ bp (Arumuganathan and Earle, 1991), and until recently, wheat was not well represented in the public databases. Quantitative traits that are difficult to follow in subsequent generations, such as resistance to FHB, would significantly benefit from EST development. The study of induction of genes during FHB infection has been limited to small libraries (Han et al., 2005; Kong et al., 2005) and only a few of the induced genes have been mapped. The objectives for this research were to partially sequence, characterize, and assign possible function to the clones of a cDNA library from wheat spikes infected with FHB (Li et al., 2001). Second, we set out to profile unigene expression during the first 24 h after inoculation in a resistant cultivar and determine if induced genes are associated with loci associated with resistance. Although the number of genes represented in the expression array is small in comparison to commercial microarrays, key defense response pathways were identified in this study.

	Materials and Methods

TOP NOTES ABSTRACT INTRODUCTION Materials and Methods Results Discussion REFERENCES

 
Sequencing and Analysis of cDNA Library
Construction of the cDNA library is described in Li et al. (2001). Escherichia coli cultures were grown in 1 mL of Terrific Broth (Sigma-Aldrich, St. Louis, MO) containing 100 mg L^–1 of ampicillin for 20 h, at 250 rpm, and 37°C. Plasmids were isolated from colonies using a Qiagen Biorobot 3000 and Qiagen Turbo 96 isolation kits (Qiagen, Valencia, CA). Templates were 5' single pass sequenced using T7 primers (IDT, Coralville, IA) and the BigDye terminator kit (Applied Biosystems, Foster City, CA). Sequenced clones containing a poly-A⁺ tail were then resequenced using SP6 (IDT). Sequence reactions were precipitated with 60% (v/v) final concentration of isopropanol and washed with 70% ethanol (v/v). After being air dried, the pellets were resuspended in highly deionized formamide (Applied Biosystems). Sequence analysis was performed on an ABI 3700 DNA Analyzer (Applied Biosystems). Sequencing data was analyzed for quality and overlap using phred, phrap, and consed (Ewing et al., 1998; Ewing and Green, 1998; Gordon et al., 1998). Sequences were deposited in the public EST database dbEST with the accession numbers BE585476–BE586199.

Amplification of cDNA Inserts
The pGEM-T vector contained the SP6 and T7 priming sites flanking the insert. The 580 singletons were used for polymerase chain reaction (PCR). PCR reactions of 50 µL contained 10 to 20 ng of plasmid, 20 pmol of each primer, 0.25 mM of each nucleotide (New England Biolabs), 1x Taq polymerase buffer (Sigma-Aldrich), 4 µM MgCl₂, and one unit of Taq polymerase (Sigma-Aldrich). The reaction was performed as follows: 92°C for 1 min; 35 cycles of 92°C for 1 min, 60°C for 2 min, and 72°C for 2 min; 72°C for 10 min. After PCR, the products were precipitated by adding isopropanol to a final concentration of 60% (v/v) then washed with 70% ethanol. The pellets were allowed to air dry and dissolved in 10 mM Tris-HCl pH 8.5 at a final concentration of 100 ng µL^–1.

Reverse Northern Analysis
cDNAs were arrayed onto Hybond N nylon membranes (Amersham Pharmacia, Piscataway, NJ) using a 96-pin arrayer (V&P Scientific, San Diego, CA, Part Number VP408). Each cDNA clone was double spotted onto a single membrane and two copies of the membrane were made. After the blots were air dried overnight, they were treated for 5 min with denaturing solution (1.5 M NaCl, 0.5 M NaOH), 5 min with neutralization solution (1.5 M NaCl, 0.5 M Tris HCl pH 8.0), washed with 2x SSC (Sambrook et al., 1989), and then air dried again before hybridization. Each blot was probed four times using probes made from cDNA.

Reverse transcription reactions contained 200 ng of mRNA from spikes 0 and 24 h following inoculation, 0.5 µg of oligo dT, 1x first strand buffer (Gibco-BRL), 1 mM dNTPs, 0.01 M DTT, and 1 U of SuperScript RT (Gibco-BRL, Carlsbad, CA). cDNA probes were labeled with antifluorescein-AP by random priming 1/5 of the RT reaction (NEN, Wellesley, MA). Blots were hybridized overnight at 65°C and washed with 2x SSC 0.5% SDS for 15 min at 65°C and 0.2x SSC 0.1% SDS for 15 min at 65°C. Detection using antifluorescein-AP conjugate and nucleic acid chemiluminescence reagents was done according to NEN protocol.

Blots were exposed to autoradiography film for 30 min. Films were analyzed using Gel Expert software (NucleoTech, San Mateo, CA). Intensity values for a 60S ribosomal subunit were used as a control, while the pGEM-T vector was used as a negative control. Means of the square root of intensities within a blot were used to determine the ratio of expression of 24 hai versus 0 hai. Ratios of the controls were used as the divisor to normalize the ratio of expression. Herwig et al. (2001) have shown that membrane arrays can determine ratios of 1:1.5 accurately with adequate replication. Therefore, an induction ratio of 1.5 was used as a cutoff.

Bin Mapping
ESTs were assigned to chromosomal bins by either Southern hybridization or by BLASTN alignment to sequences of ESTs mapped to chromosomal bins (http://wheat.pw.usda.gov/, verified 16 June 2006). Southern hybridization procedures and the Chinese Spring wheat chromosomal deletion stocks that were used are described in Qi et al. (2004).

	Results

TOP NOTES ABSTRACT INTRODUCTION Materials and Methods Results Discussion REFERENCES

 
Sequence Analysis of the Sumai 3 cDNA Library
The construction of the cDNA library used in this work was previously described in Li et al. (2001). However, details about the quality of the library were not available. A total of 864 colonies were arrayed into 96 well plates. One 96-well plate was randomly selected for determination of insert size and percentage of plasmids with insert. Amplified products demonstrated that inserts ranged from 800 bp to 2.4 kbp, with an average size of 1.47 kbp. Also, 94 of the 96 colonies contained inserts. These results indicate that the library is of good quality and the total of number sequenceable clones was 799 (92%).

Using default settings, raw sequence data from the ABI 3700 were analyzed by the base calling program, phred (Ewing et al., 1998; Ewing and Green, 1998), which assigns quality scores to each callable base. The average length of sequence called by phred was 721 bases, with an average quality score of 32.1 per base. FASTA files were created and vector sequence was trimmed using cross_match with settings of minmatch 12 and minscore 20. After trimming, the average lengths of the reads were 621 bases. Cleaned ESTs were then subjected to a batch BLAST (Altschul et al., 1990) search using BLASTX with the database option of "nr" which searches all public protein databases associated with GenBank. Phrap (Ewing et al., 1998; Ewing and Green, 1998) analysis was used to identify reads containing overlaps and identical sequences. Phrap identified 475 clones having no matching sequences and 324 clones with at least one matching sequence within the group of 799. The 324 clones present in two or more copies could be combined into 105 contiguous unique unigenes with the number of overlapping members ranging from 2 to 24 per contig. Several of the contigs aligned with the same sequence (i.e., glyceraldehyde 3-phosphate dehydrogenase). However, phrap analysis still placed the reads in different contigs. Rubisco was represented 10 times, UDP-glucose gucosyltransferase, eight times; and S-adenosylmethionine decarboxylase, six times. One representative was selected from each contig and added to the unigene set totaling 580.

Categorized Clones
Unigenes were grouped into three major categories: (i) clones aligned with sequences of known function with probabilities of 1 x 10^–5 or better; (ii) clones aligned with sequence of unknown or hypothetical function with probabilities of 1 x 10^–5 or better; and (iii) clones with weak or no alignment with sequences in the database. Eighteen categories were identified (Fig. 1 ). There were 118 unigenes (Fig. 1) that had significant alignment to sequences in the database, but no functions were assigned to them. Of these, 76 aligned to unknown proteins from Arabidopsis, five from rice (Oryza sativa L.), and the remainder from various other organisms. The probability scores ranged from 1 x 10^–5 to 1 x 10^–94 with the majority of the values around 1 x 10^–50. Also in the unigene set were 116 (Fig. 1) with no similarities to sequences in the database or the alignment was weak, including 19 in which BLASTX returned no alignment results.

View larger version (18K): [in this window] [in a new window]   Fig. 1. Categorized singletons based on BLASTX alignments.

Of particular interest to this study were genes associated with resistance and plant response to pathogen infection. The 41 unigenes identified are listed in Table 1 and were categorized according to previous reports of induction during biotic stresses. On the basis of the total library, including clone redundancy, this category represented 77 (9.6%) of the 799 sequenceable clones. The number of similar sequences found in this and other Fusarium-inoculated wheat spike libraries are listed in Tables 1, 2, and 3 (Anderson et al. [unpublished data, 2000] and Ouellet et al. [unpublished data, 2002] deposited at www.ncbi.nlm.nih.gov/entrez, verified 16 June 2006). There were seven abiotic stress-induced singletons present. The signal transduction category contained 28 singletons of which several were serine/threonine kinases. Three copies of a 14–3-3 protein A homolog were present as well as chaperonins and a GTPase-activating protein. Also present were seven unigenes identified to have similarities to cloned resistance genes.

Infection of wheat spikelets also induced numerous genes involved in other cell pathways (Table 2). Argonaute, rab5B, and cytochrome P450 CYPL1 are involved in development, cell cycle, and secondary metabolism, respectively. Gene expression pathway genes included Zn-finger proteins, elongation factors, translation initiation factors, and regulatory complex subunits. Five different membrane associated proteins as well as six proteins involved in signal transduction were also induced. Primary metabolism included numerous amino acid modifying enzymes. Present were induced homologs of pyruvate kinase and phosphate/phosphoenolpyruvate, which are involved in energy production in the Krebs cycle. Twenty-four induced genes have no known function (Table 3).

Fungal Genes within the Library
It was expected that some of the ESTs would originate from Fusarium because of the manner in which the plants were inoculated and RNA isolated. Fourteen unigenes aligned with fungal sequences in the databases from Aspergillus, Neurospora, yeast, Magnaporthe, and Rhizopus. To further determine how many of the cDNAs were from Fusarium, we probed the cDNA library with chemiluminescent labeled DNA from the F. graminearum strain GZ3639 (provided by Dr. John Leslie, Department of Plant Pathology, Kansas State University). Fifty of the 799 clones in the library hybridized with the probe including the 14 clones with alignments to fungal sequences, thus supporting the computer alignments that these were of fungal origin. Several of the fungal unigenes were common housekeeping genes of ubiquitin, heat shock proteins, and ribosomal proteins. Most of the genes did not have an assigned function and represent uncharacterized Fusarium genes. Fusarium unigenes were included on the array membranes with wheat to evaluate induction of fungal genes during infection. Three of the 50 unigenes were found to be induced (Table 4). Alignments of the induced genes putatively assigned the functions in gene expression and protein assembly.

View larger version (58K): [in this window] [in a new window]   Fig. 2. Physical location of ESTs that are induced 24 h after inoculation. Also included are expressed clones that are involved with pathogen response, based on BLASTX alignments, but not induced.

	Discussion

TOP NOTES ABSTRACT INTRODUCTION Materials and Methods Results Discussion REFERENCES

In later stages of infection, a Type II resistant plant begins to build up layers of lignin and electron dense material along the cell wall in contact with the invading hyphae (Kang and Buchenauer, 2000b.). Expression analysis of the unigene set identified two genes in the pathway of lignin formation. The first, trans-cinnamate 4-monooxygenase (BE586095) is a cytochrome P450 that catalyzes the oxidative reaction of trans-cinnamic acid to p-coumaric acid (Ro et al., 2001). Second, cinnamoyl CoA-reductase 2 (BE585541) changes cinnamoyl CoA esters to cinnamyl aldehydes (reviewed by Vance et al., 1980). The induction of these two genes indicates that the plant is preparing for infection and would support the microscopy findings of Kang and Buchenauer (2000a, 2000b). The level of phenylalanine ammonia-lyase expression does not change in the first 24 hai, which has also been seen in cotton during infection by Verticillium dahlia Kleb (Cui et al., 2000). Phenylalanine ammonia-lyase provides substrates for several phenyl-propanoid pathways and a change in expression is unlikely.

In later stages of infection, a Type II resistant plant begins to build up layers of lignin and electron dense material along the cell wall in contact with the invading hyphae.

There are no previous data to support the involvement of plant phytohormones abscisic acid, salicylic acid, and jasmonic acid in plant response to Fusarium infection. The homologs of an immediate early salicylic acid–induced glucosyltransferase (BE585502) and putative betadidin-5-O-glucosyltransferase (BE586107) were induced significantly suggesting production of salicylic acid. UDP-glucose glucosyltransferase has been found to be induced on wounding in tubers (Moehs et al., 1997) and involved in conjugating salicylic acid during pathogen attack (Lee and Raskin, 1999). Induction of a 12-oxophytodienoate reductase (OPR2) homolog in wheat suggests involvement of jasmonic acid. Formation of jasmonic acid from its precursor 12-oxophytodienoic acid is driven by OPR. opr3 mutants in Arabidopsis are male sterile, and sterility can be restored by exogenous application of jasmonic acid (Stintzi and Browse, 2000). Application of abscisic acid and environmental stress have been shown to up-regulate PDR-like ABC transporters (BE585535; Smart and Fleming, 1996). These transporters are also involved in the eflux of cytotoxic compounds across a membrane and may be involved in detoxification of DON in the cells.

As infection starts, the cells may require an increased level of energy production as evident by induction of proteins gyceraldehyde 3-phoshate dehydrogenase, pyruvate kinase, and phosphate/phosphoenolpyruvate. Carbonic anhydrase precursor (BE585604) is induced, and in plants carbonic anhydrase facilitates the interchange of CO₂ and HCO₃^–, plays a key role in fixation of photosynthesis, and is affected by changes in the cytoplasmic pH (Hou et al., 1999; Hatch and Burnell, 1990).

Infection appears to be influencing transcription and the controlling mechanisms. Induction of an Argonaute-like protein (BE586111) suggests post-transcriptional control as Argonaute proteins have been shown to be involved in the RNA-induced silencing complex in Drosophila (Hammond et al., 2001). Induction of 14–3-3 proteins, along with induction of Zn finger–like proteins, also suggests that transcription is being controlled. 14–3-3 proteins (BE586006) have been shown to regulate the intracellular localization of bZIP transcriptional activators (Igarashi et al., 2001).

Wheat EST sequences in the public database contain several libraries from Fusarium-infected wheat spikes. Several of the pathogen response genes and clones with assigned function have numerous copies in the database and indicate high level of expression during infection. The low number of unknown genes indicate rare genes. Clones with high homology to Arabidopsis and rice proteins of unknown function present opportunities to study gene function. Mutations and complementation in Arabidopsis and rice will be useful methods of assigning a function to the unknown wheat genes found in the library.

Resistance to FHB is difficult to breed for in wheat because of the quantitative nature and the numerous types of resistance. For instance, one locus QTL analysis revealed seven QTL for Type I resistance (initial infection) on chromosome arms 2DS, 3AS, 3BS, 3BC, 4DL, 5AS and 6BS and four QTL for Type II (fungal spread) on chromosome arms 2DS, 3BS, 6BL, and 7BL (Yang et al., 2005). One QTL has been extensively mapped. Qfhs.ndsu.3BS, the major QTL for Type II resistance has been localized in deletion bin 3BS8 0.78–0.87 (Liu and Anderson, 2003a). Using rice chromosome 1S–wheat 3BS synteny, 27 wheat ESTs have been localized to this region, but expression analysis was not determined (Liu and Anderson, 2003b).

Expressed clones have been associated with FHB resistance QTL. Two clones from a ‘Frontana’ library are bin mapped to regions of QTL for Type II resistance on chromosomes 2AL, 3BL, and 3DL (Han et al., 2005). None of the expressed clones in our work share sequence homology with any of the clones mapped in previous reports. However, we determined that XBE585627(3BS) and XBE585589(6BL) mapped in the same deletion bins as major QTL on 3BS and 6BL (Yang et al., 2005). Close association of an expressed clone and a locus provides a strong tool in identifying the genes involved with FHB resistance QTL.

	ACKNOWLEDGMENTS

 
We wish to thank the Kansas Wheat Commission and the McKnight Foundation for their support in the sequencing of the library. We want to thank Jianmin Zhou and Subbarat Muthukrishnan for their input during manuscript preparation, and Jon Raupp for the design of the chromosome deletion figure.

	NOTES

TOP NOTES ABSTRACT INTRODUCTION Materials and Methods Results Discussion REFERENCES

 
Abbreviations: DON, deoxynivalenol; EST, expressed sequence tag; FHB, Fusarium head blight; hai, hours after inoculation; OPR, 12-oxophytodienoate reductase.

Received for publication July 15, 2006.

	REFERENCES

TOP NOTES ABSTRACT INTRODUCTION Materials and Methods Results Discussion REFERENCES

 

• Altschul, S.F., W. Gish, W. Miller, E.W. Myers, and D.J. Lipman. 1990. Basic local alignment search tool. J. Mol. Biol. 215:403–410.[CrossRef][ISI][Medline]
• Arumuganathan, K., and E.D. Earle. 1991. Nuclear DNA content of some important plant species. Plant Mol. Biol. Rep. 9:208–218.
• Bai, G.H., and G.E. Shaner. 1994. Wheat scab: Perspective and control. Plant Dis. 78:760–766.
• Bai, G.H., G. Shaner, and H. Ohm. 2000. Inheritance of resistance to Fusarium graminearum in wheat. Theor. Appl. Genet. 100:1–8.
• Cui, Y., A.A. Bell, O. Joost, and C. Magill. 2000. Expression of potential defense response genes in cotton. Physiol. Mol. Plant Pathol. 56:25–31.
• Ewing, B., and P. Green. 1998. Base-calling of automated sequencer traces using phred. II. Error probabilities. Genome Res. 8:186–194.[Abstract/Free Full Text]
• Ewing, B., L. Hillier, M.C. Wendl, and P. Green. 1998. Base-calling of automated sequencer traces using phred. I. Accuracy assessment. Genome Res. 8:175–185.[Abstract/Free Full Text]
• Gordon, D., C. Abajian, and P. Green. 1998. Consed: A graphical tool for sequence finishing. Genome Res. 8:195–202.[Abstract/Free Full Text]
• Hammond, S.M., S. Boettcher, A.A. Caudy, R. Kobayashi, and G. Hannon. 2001. Argonaute2, a link between genetic and biochemical analyses of RNAi. Science 293:1146–1150.[Abstract/Free Full Text]
• Han, F.P., G. Fedak, T. Ouellet, H. Dan, and D.J. Somers. 2005. Mapping of genes expressed in Fusarium graminearum-infected heads of wheat cultivar ‘Frontana’. Genome 48:88–96.[Medline]
• Hatch, M.D., and J.N. Burnell. 1990. Carbonic anhydrase activity in leaves and its role in the first step of C₄ photosynthesis. Plant Physiol. 93:380–383.
• Herwig, R., P. Aanstad, M. Clark, and H. Lehrach. 2001. Statistical evaluation of differential expression on cDNA nylon arrays with replicated experiments [Online]. Available at nar.oxfordjournals.org/cgi/content/full/29/23/e117; verified 16 June 2006. Nucleic Acids Res. 29:e117.[Abstract/Free Full Text]
• Hou, W.C., J.S. Liu, H.J. Chen, T.E. Chen, C.F. Chang, and Y.H. Lin. 1999. Dioscorin, the major tuber storage protein of yam (Dioscorea batatas Decne.) with carbonic anhydrase and trypsin inhibitor activities. J. Agric. Food Chem. 47:2168–2172.[CrossRef][ISI][Medline]
• Igarashi, D., S. Ishida, J. Fukazawa, and Y. Takahashi. 2001. 14–3-3 proteins regulate intracellular localization of the bZIP transcriptional activator RSG. Plant Cell 13:2483–2497.[Abstract/Free Full Text]
• Kang, Z., and H. Buchenauer. 1999. Immunocytochemical localization of Fusarium toxins in infected wheat spikes by Fusarium culmorum. Physiol Mol. Plant Pathol. 55:275–288.[CrossRef]
• Kang, Z., and H. Buchenauer. 2000a. Cytology and ultrastructure of the infection of wheat spikes by Fusarium culmorum. Mycol. Res. 104:1083–1093.[CrossRef]
• Kang, Z., and H. Buchenauer. 2000b. Ultrastructural and immunocytochemical investigation of pathogen development and host responses in resistance and susceptible wheat spikes infected by Fusarium culmorum. Physiol. Mol. Plant Pathol. 57:255–268.[CrossRef]
• Kong, L., J.M. Anderson, and H.W. Ohm. 2005. Induction of wheat defense and stress-related genes in response to Fusarium graminearum. Genome 48:29–40.[Medline]
• Lee, H., and I. Raskin. 1999. Purification, cloning, and expression of a pathogen inducible UDP-glucose:salicylic acid glucosyltransferase from tobacco. J. Biol. Chem. 274:36637–36642.[Abstract/Free Full Text]
• Li, W.L., J.D. Faris, S. Muthukrishnan, D.J. Liu, P.D. Chen, and B.S. Gill. 2001. Isolation and characterization of novel cDNA clones of acidic chitinases and ß-1,3-glucanases from wheat spikes infected by Fusarium graminearum. Theor. Appl. Gen. 102:353–362.[CrossRef]
• Liu, S., and J.A. Anderson. 2003a. Marker assisted evaluation of Fusarium head blight resistant wheat germplasm. Crop Sci. 43:760–766.[Abstract/Free Full Text]
• Liu, S., and J.A. Anderson. 2003b. Targeted molecular mapping of a major wheat QTL for Fusarium head blight resistance using wheat ESTs and synteny with rice. Genome 46:817–823.[Medline]
• McMullen, M., R. Jones, and D. Gallenberg. 1997. Scab of wheat and barley: A re-emerging disease of devastating impact. Plant Dis. 81:1340–1348.
• Mesterhazy, A. 1995. Types and components of resistance to Fusarium head blight of wheat. Plant Breed. 114:377–386.[CrossRef]
• Moehs, C.P., P.V. Allen, M. Friedman, and W.R. Belknap. 1997. Cloning and expression of solanidine UDP-glucose glucosyltransferase from potato. Plant J. 11:227–236.[CrossRef][ISI][Medline]
• Pritsch, C., G.J. Muehlbauer, W.R. Bushnell, D.A. Somers, and C.P. Vance. 2000. Fungal development and induction of defense response genes during infection of wheat spikes by Fusarium graminearum. Mol. Plant Microbe Interact. 13:159–169.[ISI][Medline]
• Pugh, G.W., H. Johan, and J.G. Dickson. 1933. Factors affecting infection of wheat heads by Gibberella saubinetti. J. Agric. Res. 46:771–797.
• Qi, L.L, B. Echalier, S. Chao, G.R. Lazo, G.E. Butler, O.D. Anderson, E.D. Akhunov, J. Dvorak, A.M. Linkiewicz, A. Ratnasiri, J. Dubcovsky, C.E. Bermudez-Kandianis, R. A. Greene, R. Kantety, C.M. La Rota, J.D. Munkvold, S.F. Sorrells, M. E. Sorrells, M. Dilbirligi, D. Sidhu, M. Erayman, H.S. Randhawa, D. Sandhu, S.N. Bondareva, K.S. Gill, A.A. Mahmoud, X.-F. Ma, Miftahudin, J.P. Gustafson, E.J. Conley, V. Nduati, J.L. Gonzalez-Hernandez, J.A. Anderson, J.H. Peng, N.L.V. Lapitan, K.G. Hossain, V. Kalavacharla, S.F. Kianian, M.S. Pathan, D.S. Zhang, H.T. Nguyen, D.-W. Choi, R.D. Fenton, T.J. Close, P.E. McGuire, C.O. Qualset, and B. S. Gill. 2004. A chromosome bin map of 16,000 expressed sequence tag loci and distribution of genes among the three genomes of polyploid wheat. Genetics. 168:701–712[Abstract/Free Full Text]
• Ro, D.K., N. Mah, B.E. Ellis, and C.J. Douglas. 2001. Functional characterization and subcellular localization of poplar (Populus trichocarpa x Populus deltoides) cinnamate 4-hydroxylase. Plant Physiol. 126:317–329.[Abstract/Free Full Text]
• Sambrook, J., E.F. Fritsch, and T. Maniatis. 1989. Molecular cloning: A laboratory manual. 2nd ed. Cold Spring Harbor Laboratory Press, New York.
• Schroeder, H.W., and J.J. Christensen. 1963. Factors affecting resistance of wheat to scab caused by Gibberella zeae. Phytopathology 53:831–838.[ISI]
• Singh, R.P., H. Ma, and S. Rajaram. 1995. Genetic analysis of resistance to scab in spring wheat cultivar Frontana. Plant Dis. 79:238–240.
• Smart, C.C., and A.J. Fleming. 1996. Hormonal and environmental regulation of a plant PDR5-like ABC transporter. J. Biol. Chem. 271:19351–19357.[Abstract/Free Full Text]
• Stintzi, A., and J. Browse. 2000. The Arabidopsis male-steril mutant, opr3, lacks the 12-oxophytodienoic acid reductase reqruied for jasmonate synthesis. Proc. Natl. Acad. Sci. USA 97:10625–10630.[Abstract/Free Full Text]
• Vance, C.P., T.K. Kirk, and R.T. Sherwood. 1980. Lignification as a mechanism of disease resistance. Ann. Rev. Phytopathol. 18:259–288.[CrossRef][ISI]
• Van Ginkel, M., W. Van Der Schaar, Z.P. Yang, and S. Rajaram. 1996. Inheritance of resistance to Fusarium head blight in two wheat cultivars from Brazil and China. Plant Dis. 80:863–867.
• Wang, Y.Z., and J.D. Miller. 1988. Screening techniques and sources of resistance to Fusarium head blight. p. 239–250. In A.R. Klatt (ed.) Wheat production constraints in tropical environments. CIMMYT, Lisboa, Mexico.
• Yang, Z., J. Gilbert, G. Fedak, and D.J. Somers. 2005. Genetic characterization of QTL associated with resisance to Fusarium head blight in a doubled-haploid spring wheat population. Genome 48:187–196.[Medline]

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hill-Ambroz, K. Articles by Fellers, J. P. Search for Related Content PubMed Articles by Hill-Ambroz, K. Articles by Fellers, J. P. Agricola Articles by Hill-Ambroz, K. Articles by Fellers, J. P.