Proceedings of the XLVI Italian Society of Agricultural Genetics - SIGA Annual Congress

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Poster Abstract - 5.10

BOTRYTIS CINEREA INFECTION ACTIVATES ETHYLENE AND JASMONIC ACID-RELATED GENE EXPRESSION IN HARVESTED TOMATO FRUITS

De Martinis D.

ENEA, Ente Nazionale per le Nuove Tecnologie, Energia e Ambiente, UTS Biotecnologie, Protezione della Salute e degli Ecosistemi, Sezione di Genetica e Genomica Vegetale, C.R. Casccia, Via Anguillarese 301, 00060 Roma, Italy

plant-pathogen interactions, tomato, fruit, Botrytis cinerea, ethylene, jasmonic acid, gene expression

The aim of our study is to identify (new) genes related to (new) metabolic pathways or regulatory pathways that affect fruit spoilage, nutritional quality and marketability.

We are studying the mechanism of fruit spoilage derived from Botrytis cinerea (Botrytis) mould in tomato berry fruit. Botrytis is a plant pathogenic fungus that infects over 200 different plant species and provokes significant crop losses, particularly after harvest. Infection results in volatile compounds release from the tomato berry fruit; ethylene, ethanol, short chain aldehydes (hexenals) and carbon dioxide, that may be useful markers to monitor the physiological status of the infected fruits, as early signals of disease progression. We used a RT-PCR approach to monitor fruit (tomato) and fungus (Botrytis) gene expression related to the monitored volatile compounds in fruit in standard and infected conditions. We monitored gene related expression of ACCsynthase (ACS) and ACCoxidase (ACO) for ethylene biosynthesis, lipoxygenase (LOX), allene-oxide synthase (AOS) hydroperoxide lyase (HPL) for the biosynthetic pathway of potential natural pesticides (hexenals and jasmonic acid). Preliminary analysis in infected tomato fruits provided the expression profile of this gene pool during disease progression, clearly showing the activation of ACO and AOS genes and the Jasmonate/ethylene-dependent PDF1.2 gene. Our analysis based on the monitoring of specific metabolic compounds related to fruit ripening/spoilage/pathogenesis will indicate “key” time-point of physiological changes of the fruit. Those key points will be evaluated for cDNA library construction that will be used to study massive differential gene expression by serial analysis of gene expression (SAGE) and by cDNA-microarray technology. The expression profiling will enable the analysis of thousand of genes, thus enabling the isolation of cDNA clones whose expression is related to spoilage/pathogenesis maybe unravelling new metabolic pathway or differential regulation of described ones.