POSSIBLE ROLE IN LIPID SIGNALLING OF STRAWBERRY CLASS TAU GSTs EXPRESSED IN A BIOTIC INTERACTION

TONELLO, URSULA; CASTAGNARO, ATILIO P.; DIAZ RICCI, JUAN C

San Miguel de Tucumán

Congreso; 45º Reunión Anual de la Sociedad de Argentina de Bioquímica y Biología Molecular; 2009

Sociedad de Argentina de Bioquímica y Biología Molecular

In plants, Glutathione S-transferases (GSTs) belong to a family of proteins grouped into four main classes (tau, phi, theta and zeta), playing major roles in protection from biotic and abiotic stresses. We have isolated 17 GSTs class tau sharing high identity with other plant GSTs from strawberry leaves 48 hpi with the fungal strain M23. Proteins presented identities ranging from 29 to 99%, showing conservation in residues involved in GSH binding, and diversification in the H site at the C-terminal domain. Based in total sequence alignments and 3’UTR motifs, five different groups were found in FaGSTs. Comparative phylogenetic analyses among arabidopsis and strawberry tau class GSTs indicated that the proteins expressed in the biotic stress in leaves are orthologues of the AtGSTs induced by salicylic acid (SA) and in response to cyclopentenones. These results agree with the increased values of malondialdehyde assessed as TBARS in leaves extracts 36 hpi, indicating that the generation of lipoperoxide precedes the induction of Fagsts. We have also observed that total SA was increased in phloema exudates in challenged strawberry plants. The expression changes in Fagsts transcripts were confirmed using real time PCR. Different approaches for functional studies of these paralogous genes in strawberry will help to clarify the role of class tau GST members in biotic interactions.