Global transcriptional response to heat shock and grapevine wood in Lasiodiplodia theobromae

PAOLINELLI MARCOS; VILLALOBOS-ESCOBEDO JOSE MANUEL; LÓPEZ-HERNÁNDEZ JOSÉ FABRICIO; RENDÓN-ANAYA MARTHA; HERRERA-ESTRELLA ALFREDO HERIBERTO; HERNÁNDEZ-MARTÍNEZ RUFINA

Pasadena

Congreso; APS annual meeting; 2015

Lasiodiplodia theobromae is Botryosphaeriaceae fungus that causes grapevine trunk disease, especially in regions with hot climate. To test for the hypothesis that heat shock (HS) triggers its pathogenicity, a transcriptomic study in the presence or absence of grapevine wood (GW) was performed. A total of 19860 de novo assembled transcripts were obtained with an average length of 658 bp and an N50=2472 bp. Fourty-nine per cent showed homology with other Botryosphaeriaceae fungi, such as Neofusicoccum parvum and Macrophomina phaseolina; functional annotation was obtained for 38% of them. In total, 1225 genes were up-regulated and 1114 down-regulated in all evaluated conditions (11%). Genes up-regulated in the presence of GW but down-regulated with HS, were found mainly involved in O-glycosyl hydrolysis, while genes induced by HS were enriched in oxido-reductase activity. One of the transcripts heavily induced in response to HS encodes a putative intradiol ring cleavage dioxygenase, a key enzyme in the benzoate (and phenolics) degradation metabolic pathway. L. theobromae grows well using only benzoate as carbon source, suggesting that its presence promotes mycelial growth during HS. The marked change in carbon-source utilization, from glucose-based to amino acid-based and oxido-reductive metabolism together with the induction of putatively secreted pathogenicity factors suggest that a change to a pathogenicity behavior occurs in response to HS.