Differential gene expression, induced by salicylic acid and Fusarium oxysporum f. sp. lycopersici infection, in tomato

Abstract

-The objective of this work was to determine the transcript profi le of tomato plants (Lycopersicon esculentum Mill.), during Fusarium oxysporum f. sp. lycopersici infection and after foliar application of salicylic acid. The suppression subtractive hybridization (SSH) technique was used to generate a cDNA library enriched for transcripts differentially expressed. A total of 307 clones was identifi ed in two subtractive libraries, which allowed the isolation of several defense-related genes that play roles in different mechanisms of plant resistance to phytopathogens. Genes with unknown roles were also isolated from the two libraries, which indicates the possibility of identifying new genes not yet reported in studies of stress/defense response. The SSH technique is effective for identifi cation of resistance genes activated by salicylic acid and F. oxysporum f. sp. lycopersici infection. Not only the application of this technique enables a cost effective isolation of differentially expressed sequences, but also it allows the identifi cation of novel sequences in tomato from a relative small number of sequences.Index terms: Lycopersicon esculentum, cDNA libraries, complementary DNA, gene expression, salicylic acids, suppression subtractive hybridization. Expressão diferencial de genes induzida por ácido salicílico e por Fusarium oxysporum f. sp. lycopersici, em tomateiroResumo -O objetivo deste trabalho foi determinar o perfi l de transcritos em plantas de tomate (Lycopersicon esculentum Mill.), durante a infecção com Fusarium oxysporum f. sp. lycopersici e após a aplicação foliar de ácido salicílico. A técnica de hibridização subtrativa por supressão (SSH) foi utilizada para gerar uma biblioteca de cDNA enriquecida por transcritos diferencialmente expressos. Foram identifi cados 307 clones, em duas bibliotecas subtrativas, que permitiram o isolamento de diversos genes de defesa com função em diferentes processos relacionados à resistência vegetal contra patógenos. Também foram isolados, nas duas bibliotecas, genes com função desconhecida, o que indica a possibilidade de identifi cação de novos genes que ainda não tenham sido relatados em estudos anteriores de resposta a estresses e defesa, em plantas. A técnica SSH é efi ciente em identifi car genes de resistência, ativados pelo ácido salicílico e pela infecção com Fusarium oxysporum f. sp. lycopersici. A aplicação dessa técnica não apenas possibilita isolar seqüências diferencialmente expressas, a baixo custo, como também permite a identifi cação de novas seqüências, em tomate, a partir de um número relativamente pequeno de seqüências.Termos para indexação: Lycopersicon esculentum, bibliotecas de cDNA, DNA complementar, expressão gênica, ácido salicílico, hibridização subtrativa por supressão.

Isolation and Characterization of Chitinase from Tomato Infected by Fusarium oxysporum f. sp. lycopersici

“…These data corroborate with those found in the experiment of do Amaral et al. , which suggests that the gene found in the EST subtractive library is really involved in the response to fungus inoculation, that is, it is being differentially expressed after contact with the pathogen in BHRS genotype.…”

Transcriptional profiling of watermelon during its incompatible interaction with Fusarium oxysporum f. sp. niveum

“…It is well known that β-1, 3-glucanases and chitinases act either directly by degrading the fungal cell wall or indirectly by releasing oligosaccharide elicitors of defense reactions, and thus play important roles in defence response against fungal infection. Differential expression of chitinases and β-1, 3-glucanases has been observed during compatible plant-fungal interactions in other plant-fungus interaction systems (Cheong et al 2000;Bieri et al 2003;Amaral et al 2008). Therefore, it is likely that at this stage of infection, up-regulation of pathogenesisrelated proteins genes especially chitinases and β-1, 3-glucanases indicated that a comprehensive network of defence response was activated in watermelon plants upon FON1 infection.…”

“…Down-regulation of the aquaporins and drought-responsive genes may contribute to the development of wilt symptoms (Dowd et al 2004;Amaral et al 2008;Sade et al 2009;Zhou and Wu 2009). At this stage, several transcription factors were significantly induced, e.g., ERF-like proteins, Myb family transcription factors, ethylene-responsive transcriptional coactivator, and RING-H 2 finger protein precursor.…”

“…Genome-wide expression profiling of plants infected with Fusarium oxysporum has been reported in several crop plant species, including cotton (Dowd et al 2004), chickpea (Gupta et al 2010) and tomato (Amaral et al 2008). However, no similar study has been reported in watermelon.…”

Protein extraction method for the proteomic study of Zymomonas mobilis during production of ethanol and levans

“…The identification of genes has contributed to the understanding of the mechanism of modulation of microorganisms under different abiotic conditions (Amaral et al, 2008). However, transcriptional changes do not reflect the expression of proteins (Gygi et al, 1999) since post-transcriptional processes, which change the amount of active protein derived from synthesis, modification, and degradation of the protein, are not taken into consideration.…”