The <it<Ve</it<-mediated resistance response of the tomato to <it<Verticillium dahliae </it<involves H<sub<2</sub<O<sub<2</sub<, peroxidase and lignins and drives <it<PAL </it<gene expression

<p<Abstract</p< <p<Background</p< <p<<it<Verticillium dahliae </it<is a fungal pathogen that infects a wide range of hosts. The only known genes for resistance to <it<Verticillium </it<in the Solanaceae are found in the tomato (<it<Solanum...
Ausführliche Beschreibung

<p<Abstract</p< <p<Background</p< <p<<it<Verticillium dahliae </it<is a fungal pathogen that infects a wide range of hosts. The only known genes for resistance to <it<Verticillium </it<in the Solanaceae are found in the tomato (<it<Solanum lycopersicum</it<) <it<Ve </it<locus, formed by two linked genes, <it<Ve1 </it<and <it<Ve2</it<. To characterize the resistance response mediated by the tomato <it<Ve </it<gene, we inoculated two nearly isogenic tomato lines, LA3030 (<it<ve</it</<it<ve</it<) and LA3038 (<it<Ve</it</<it<Ve</it<), with <it<V. dahliae</it<.</p< <p<Results</p< <p<We found induction of H<sub<2</sub<O<sub<2 </sub<production in roots of inoculated plants, followed by an increase in peroxidase activity only in roots of inoculated resistant plants. Phenylalanine-ammonia lyase (PAL) activity was also increased in resistant roots 2 hours after inoculation, while induction of PAL activity in susceptible roots was not seen until 48 hours after inoculation. Phenylpropanoid metabolism was also affected, with increases in ferulic acid, <it<p</it<-coumaric acid, vanillin and <it<p</it<-hydroxybenzaldehyde contents in resistant roots after inoculation. Six tomato <it<PAL </it<cDNA sequences (<it<PAL1 </it<- <it<PAL6</it<) were found in the SolGenes tomato EST database. RT-PCR analysis showed that these genes were expressed in all organs of the plant, albeit at different levels. Real-time RT-PCR indicated distinct patterns of expression of the different <it<PAL </it<genes in <it<V. dahliae</it<-inoculated roots. Phylogenetic analysis of 48 partial <it<PAL </it<cDNAs corresponding to 19 plant species grouped angiosperm <it<PAL </it<sequences into four clusters, suggesting functional differences among the six tomato genes, with <it<PAL2 </it<and <it<PAL6 </it<presumably involved in lignification, and the remaining <it<PAL </it<genes implicated in other biological processes.</p< <p<An increase in the synthesis of lignins was found 16 and 28 days after inoculation in both lines; this increase was greater and faster to develop in the resistant line. In both resistant and susceptible inoculated plants, an increase in the ratio of guaiacyl/syringyl units was detected 16 days after inoculation, resulting from the lowered amount of syringyl units in the lignins of inoculated plants.</p< <p<Conclusions</p< <p<The interaction between the tomato and <it<V. dahliae </it<triggered a number of short- and long-term defensive mechanisms. Differences were found between compatible and incompatible interactions, including onset of H<sub<2</sub<O<sub<2 </sub<production and activities of peroxidase and PAL, and phenylpropanoid metabolism and synthesis of lignins.</p< Ausführliche Beschreibung

Autor*in:	Merino Fuencisla [verfasserIn] Novo-Uzal Esther [verfasserIn] Pomar Federico [verfasserIn] Gayoso Carmen [verfasserIn] Martínez de Ilárduya Óskar [verfasserIn]

Format:	E-Artikel
Sprache:	Englisch

Erschienen:	2010

Übergeordnetes Werk:	In: BMC Plant Biology - BMC, 2003, 10(2010), 1, p 232
Übergeordnetes Werk:	volume:10 ; year:2010 ; number:1, p 232

Links:	Link aufrufen Link aufrufen Link aufrufen Journal toc

DOI / URN:	10.1186/1471-2229-10-232

Katalog-ID:	DOAJ058857540