Fusarium verticillioides is responsible for Fusarium ear rot in maize and mycotoxin contamination of grain. Genomic regions and candidate genes for resistance to Fusarium were detected through the comparison of resistant (CO441) and susceptible (CO354) maize lines, by following three different approaches: Quantitative Trait Locus (QTL), transcriptomic (RNASeq) and metabolomic analyses. 184 F2:3 families (CO441xCO354) were evaluated in two different environments in 2011 and artificially infected with two side-needle inoculation methods (pin-bar and toothpick). Significant genotypic variation in response to infection was detected. On the basis of a genetic draft map containing 74 polymorphic SSRs markers, 8 common QTLs for Fusarium ear rot resistance and fumonisin contamination reduction were revealed. Candidate genes for resistance resulted from differentially expressed genes before and 72 hours post infection of CO441 kernels through RNASeq technology. Putative metabolites related to resistance were detected through high resolution LC-MS in both maize lines. Candidate genes and metabolites mapped in pathways involved in defense mechanism: phenylalanine, tyrosine and tryptophan biosynthesis, phenylpropanoid and flavonoid biosynthesis, linoleic and α-linolenic acid metabolism. Abundant genic transcripts derived from terpenoid and diterpenoid biosynthesis. Candidate genes will be screened for polymorphisms between the two maize lines in order to enrich the linkage map.
Fusarium verticillioides è responsabile della fusariosi della spiga in mais e della contaminazione della granella con micotossine. Sono state individuate le regioni geniche e i geni candidati per la resistenza a Fusarium dal confronto tra una linea di mais resistente (CO441) e una suscettibile (CO354), impiegando tre diversi approcci: analisi QTL, analisi trascrittomica (RNASeq) e analisi metabolomica. 184 famiglie F2:3 (CO441xCO354) sono state valutate in due diversi ambienti nell’anno 2011 e inoculate artificialmente con due diverse tecniche (forchetta e stuzzicadente). E’ stata rilevata una significativa variazione genotipica in risposta all’infezione. Sulla base di una mappa preliminare di linkage molecolare contenente 74 marcatori microsatelliti polimorfici, sono stati determinati 8 QTLs comuni alla resistenza alla fusariosi della spiga e alla riduzione della contaminazione da fumonisine. Sono stati considerati geni candidati per la resistenza i geni differenzialmente espressi, risultanti dall’ RNASeq, in semi di mais CO441 prima e 72 ore dopo l’infezione. I metaboliti putativi correlati alla resistenza sono stati rilevati tramite high resolution LC-MS in entrambe le linee di mais. I geni candidati e i metaboliti mappano in pathway coinvolti nei meccanismi di difesa: fenilalanina, tirosina e triptofano biosintesi, fenilpropanoidi e flavonoidi biosintesi, metabolismo dell’acido linoleico e α-linolenico. Abbondanti trascritti derivano dalla biosintesi dei terpenoidi e dei diterpenoidi. Nei geni candidati verranno ricercati polimorfismi fra le due linee di mais e che andranno ad arricchire la mappa di linkage molecolare.
Maschietto, V., Identification of genes, QTLs and metabolites for Fusarium aer rot resistance in maize, 2013-02-21 [https://hdl.handle.net/10807/285795]
Identification of genes, QTLs and metabolites for Fusarium aer rot resistance in maize
Maschietto, Valentina
2013
Abstract
Fusarium verticillioides is responsible for Fusarium ear rot in maize and mycotoxin contamination of grain. Genomic regions and candidate genes for resistance to Fusarium were detected through the comparison of resistant (CO441) and susceptible (CO354) maize lines, by following three different approaches: Quantitative Trait Locus (QTL), transcriptomic (RNASeq) and metabolomic analyses. 184 F2:3 families (CO441xCO354) were evaluated in two different environments in 2011 and artificially infected with two side-needle inoculation methods (pin-bar and toothpick). Significant genotypic variation in response to infection was detected. On the basis of a genetic draft map containing 74 polymorphic SSRs markers, 8 common QTLs for Fusarium ear rot resistance and fumonisin contamination reduction were revealed. Candidate genes for resistance resulted from differentially expressed genes before and 72 hours post infection of CO441 kernels through RNASeq technology. Putative metabolites related to resistance were detected through high resolution LC-MS in both maize lines. Candidate genes and metabolites mapped in pathways involved in defense mechanism: phenylalanine, tyrosine and tryptophan biosynthesis, phenylpropanoid and flavonoid biosynthesis, linoleic and α-linolenic acid metabolism. Abundant genic transcripts derived from terpenoid and diterpenoid biosynthesis. Candidate genes will be screened for polymorphisms between the two maize lines in order to enrich the linkage map.File | Dimensione | Formato | |
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