Pepper 9- and 13-lipoxygenase genes are differentially activated by two tobamoviruses and by hormone treatments

• DOI: 10.1016/j.pmpp.2015.08.004
• Publication Date: 2015-08-13T18:31:18Z
• Authors: Csilla Juhász; István Tóbiás; Attila L. Ádám; György Kátay; Gábor Gullner
• Keywords: 0303 health sciences; 03 medical and health sciences; QK10 Plant physiology / növényélettan; 3. Good health

Abstract Two novel pepper 13-lipoxygenase ( LOX ) genes were cloned and their expressions were compared with those of three 9- LOX genes in pepper leaves inoculated with two different tobamoviruses. Obuda pepper virus (ObPV) inoculation led to a massive induction of pathogenesis-related genes and to the development of hypersensitive reaction (incompatible interaction), while Pepper mild mottle virus (PMMoV) inoculation resulted in a compatible interaction. Both virus infections markedly activated the expression of the two novel 13-LOX s. The magnitudes of induction of 13- LOXs did not differ substantially between the ObPV- and PMMoV-inoculated leaves. The induction of three 9-LOX s was markedly more robust and rapid in ObPV-inoculated leaves than in PMMoV-inoculated ones. LOX s were very differentially activated in pepper leaves treated with defense hormones. A large number of hormone-related cis -regulatory elements were identified in the promoter regions of LOXs . ObPV inoculation resulted also in the substantial up-regulation of an omega-6-fatty acid desaturase gene. Our results suggest that 9-LOX-dependent pathways are more probably involved in the suppression of virus replication than 13-LOX-dependent plant responses.