Global transcriptional analysis suggests Lasiodiplodia theobromae pathogenicity factors involved in modulation of grapevine defensive response. (December 2016)

• Record Type: Journal Article
• Authors: Paolinelli-Alfonso, Marcos; Villalobos-Escobedo, José; Rolshausen, Philippe; Herrera-Estrella, Alfredo; Galindo-Sánchez, Clara; López-Hernández, José; Hernandez-Martinez, Rufina
• Is Part Of: BMC genomics. Volume 17:Number 1(2016)
• Page Start: 1
• Page End: 20
• Publication Date: 2016-12
• Subjects: Fungal gene expression -- Botryosphaeria dieback -- Vitis vinifera -- RT-qPCR -- Graevine vascular diseases -- RNA-seq -- Transcriptome -- Melanin; Genomes -- Periodicals; Gene mapping -- Periodicals; Genomics -- Periodicals; Base Sequence -- Periodicals; Chromosome Mapping -- Periodicals; Genetic Techniques -- Periodicals; Sequence Analysis, DNA -- Periodicals; 572.8605
• DOI: 10.1186/s12864-016-2952-3
• Languages: English
• ISSNs: 1471-2164

Abstract

Abstract Background Lasiodiplodia theobromae is a fungus of the Botryosphaeriaceae that causes grapevine vascular disease, especially in regions with hot climates. Fungi in this group often remain latent within their host and become virulent under abiotic stress. Transcriptional regulation analysis ofL. theobromae exposed to heat stress (HS) was first carried out in vitro in the presence of grapevine wood (GW) to identify potential pathogenicity genes that were later evaluated forin planta expression. Results A total of 19, 860de novo assembled transcripts were obtained, forty-nine per cent of which showed homology to the Botryosphaeriaceae fungi, Neofusicoccum parvum orMacrophomina phaseolina . Three hundred ninety-nine have homology with genes involved in pathogenic processes and several belonged to expanded gene families in others fungal grapevine vascular pathogens. Gene expression analysis showed changes in fungal metabolism of phenolic compounds; where genes encoding for enzymes, with the ability to degrade salicylic acid (SA) and plant phenylpropanoid precursors, were up-regulated during in vitro HS response, in the presence of GW. These results suggest that the fungal L-tyrosine catabolism pathway could help the fungus to remove phenylpropanoid precursors thereby evading the host defense response. Thein planta up-regulation of salicylate hydroxylase, intradiol ring cleavage dioxygenase and fumarylacetoacetase encoding genes, further supported this hypothesis. Those genes were even more up-regulated in HS-stressed plants, suggesting that fungus takes advantage of the increased phenylpropanoid precursors produced under stress. Pectate lyase was up-regulated while a putative amylase was down-regulatedin planta, this could be associated with an intercellular growth strategy during the first stages of colonization. Conclusions L. theobromae transcriptome was established and validated. Its usefulness was demonstrated through the identification of genes expressed during the infection process. Our results support the hypothesis that heat stress facilitates fungal colonization, because of the fungus ability to use the phenylpropanoid precursors and SA, both compounds known to control host defense.