Peroxisomal polyamine oxidation in the Arabidopsis-Botrytis interaction

ALVARADO-GUITRON, P; JASSO ROBLES, FI; GONZALEZ, ME; PIECKENSTAIN, FL; GUERRERO-GONZÁLEZ, ML; JIMÉNEZ-BREMONT, JF; DE DIEGO, N; RODRÍGUEZ-KESSLER, M

Congreso; XX National Plant Biochemistry and Molecular Biology Congress, 3rd Meeting of the Mexico Section of the American Society of Plant Biologists, 13th Mexico-USA Plant Biology Symposium; 2023

Regulation of polyamine levels during plant infection through their catabolism has aparticular impact depending on the pathogen´s lifestyle. Polyamines such as spermidine and spermine are catabolized by FAD-dependent polyamine oxidases. This study aims to understand the role of peroxisomal spermidine and spermine oxidation during the Arabidopsis thaliana - Botrytis cinerea interaction. In A. thaliana plants of the wild-type Col-0 ecotype, an increase in PAO activity for the substrates spermidine and spermine was observed 24 hours post-inoculation with the fungus. Furthermore, the lesion size caused by B. cinerea was determined in A. thaliana leaves treated with the PAO inhibitor1,8- diaminooctane and with polyamines (spermidine and spermine), or with combined treatments. Expression levels of the Arabidopsis AtPAO gene family were determined,showing that the AtPAO3 gene expression increased 72 hpi. Little is known about theparticipation of the AtPAO3 gene encoding a peroxisomal enzyme in plant defense, for thispurpose, a T-DNA insertional mutant line and two 35S::AtPAO3 overexpression lines were used. Both mutant and 35SS::AtPAO3 overexpression lines showed smaller lesion sizes compared to the parental Col-0 ecotype. The role of reactive oxygen species and polyamine oxidation mediated by the AtPAO3 gene in plant defense is discussed.