|HUFFAKER, ALISA - University Of California|
|SCHMELZ, ERIC - University Of California|
Submitted to: Plant Signaling and Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/26/2015
Publication Date: 2/1/2016
Citation: Christensen, S.A., Huffaker, A., Hunter III, C.T., Alborn, H.T., Schmelz, E. 2016. A maize death acid, 10-oxo-11-phytoenoic acid, is the predominant cyclopentenone signal present during multiple stress and developmental conditions. Plant Signaling and Behavior. 11(2):e1120395.
Interpretive Summary: Pathogen and insect attack on crop plants can be countered by potent defense molecules. In a recent study, we investigated the function of two lipoxygenase (LOX) derived compounds, namely10-oxo-11-phytoenoic acid (10-OPEA) and 10-oxo-11-phytodienoic acid (10-OPDA). 10-OPEA was found to be abundantly produced in response to fungal infection caused by Southern leaf blight (SLB - Cochliobolus heterostrophus) and displayed strong antimicrobial and growth inhibition activity against pathogens and insects, respectively. To further elucidate the function of 10-OPEA and to compare its abundance and distribution to 10-OPDA and the other well-studied structurally similar LOX derived cyclopentenone12-oxo-phytodienoic acid (12-OPDA), we carried out pathogen, insect, and wounding experiments. Our results demonstrate that 10-OPEA is the predominate LOX-derived plant defense cyclopentenone produced in SLB infected leaf tissues, damaged silks, and hydroponic roots.
Technical Abstract: Recently we investigated the function of the 9-lipoxygenase (LOX) derived cyclopentenones 10-oxo-11-phytoenoic acid (10-OPEA) and 10-oxo-11-phytodienoic acid (10-OPDA) and identified their C-14 and C-12 derivatives. 10-OPEA accumulation is elicited by fungal and insect attack and acts as a strong inhibitor of microbial and herbivore growth. Although structurally similar, comparative analyses between 10-OPEA and its 13-LOX analog 12-oxo-phytodienoic acid (12-OPDA) demonstrate specificity in transcript accumulation linked to detoxification, secondary metabolism, jasmonate regulation, and protease inhibition. As a potent cell death signal, 10-OPEA activates cysteine protease activity leading to ion leakage and apoptotic-like DNA fragmentation. In this study we further elucidate the distribution, abundance, and functional roles of 10-OPEA, 10-OPDA, and 12-OPDA, in diverse organs under pathogen- and insect-related stress.