An operon for production of bioactive gibberellin A(4) phytohormone with wide distribution in the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola

Autor(es)

Nagel, Raimund ; Turrini, Paula C. G. ; Nett, Ryan S. ; Leach, Jan E. ; Verdier, Valerie ; Van Sluys, Marie-Anne ; Peters, Reuben J.

• Tipo de documento: Artigo Científico
• Fonte: NEW PHYTOLOGIST; v. 214, n. 3, p. 7-pg., 2017-05-01.

Resumo

Phytopathogens have developed elaborate mechanisms to attenuate the defense response of their host plants, including convergent evolution of complex pathways for production of the GA phytohormones, which were actually first isolated from the rice fungal pathogen Gibberella fujikuroi. The rice bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc) has been demonstrated to contain a biosynthetic operon with cyclases capable of producing the universal GA precursor ent-kaurene. Genetic (knock-out) studies indicate that the derived diterpenoid serves as a virulence factor for this rice leaf streak pathogen, serving to reduce the jasmonic acid-mediated defense response. Here the functions of the remaining genes in the Xoc operon are elucidated and the distribution of the operon in X. oryzae is investigated in over 100 isolates. The Xoc operon leads to production of the bioactive GA(4), an additional step beyond production of the penultimate precursor GA(9) mediated by the homologous operons recently characterized from rhizobia. Moreover, this GA biosynthetic operon was found to be widespread in Xoc (> 90%), but absent in the other major X. oryzae pathovar. These results indicate selective pressure for production of GA(4) in the distinct lifestyle of Xoc, and the importance of GA to both fungal and bacterial pathogens of rice. (AU)

• Processo FAPESP: 08/52074-0 - Sugarcane genome sequence: plant transposable elements are active contributors to gene structure variation, regulation and function
• Beneficiário: Marie-Anne Van Sluys
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático
• Processo FAPESP: 12/24954-0 - Influência de elementos móveis em linhagens de Xanthomonas oryzae
• Beneficiário: Paula Cristina Gasperazzo Turrini
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 15/24956-1 - Influência de elementos móveis em linhagens de Xanthomonas oryzae
• Beneficiário: Paula Cristina Gasperazzo Turrini
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado