EPIP-Evoked Modifications of Redox, Lipid, and Pectin Homeostasis in the Abscission Zone of Lupine Flowers

• Published in: International journal of molecular sciences Vol. 22; no. 6; p. 3001
• Main Authors: Wilmowicz, Emilia, Kućko, Agata, Pokora, Wojciech, Kapusta, Małgorzata, Jasieniecka-Gazarkiewicz, Katarzyna, Tranbarger, Timothy John, Wolska, Magdalena, Panek, Katarzyna
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 16.03.2021; MDPI
• Subjects: Abortion; Abscission; Antioxidants; Ascorbic acid; Catalase; cell wall; Cell Wall - drug effects; Cell Wall - metabolism; Cell walls; crops; Cytoplasm; Demethylation; Experiments; fatty acids; flower abscission zone; Flowers; Flowers & plants; Flowers - drug effects; Flowers - growth & development; Gene expression; Homeostasis; Homeostasis - drug effects; Hydrogen peroxide; Hydrogen Peroxide - metabolism; Kinases; L-Ascorbate peroxidase; Lipid metabolism; Lipids; Lipids - chemistry; Lupinus - drug effects; Lupinus - growth & development; Oxidation-Reduction; Oxidative stress; Pectin; Pectins - metabolism; Peptides; Peptides - pharmacology; Peroxidase; Phosphatidic acid; Physiology; Plant Proteins - genetics; Plant Proteins - metabolism; Signal transduction; Signal Transduction - drug effects; Superoxide dismutase; Superoxide Dismutase - metabolism; yellow lupine; crops; fatty acids; cell wall; oxidative stress; yellow lupine; flower abscission zone
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22063001

Yellow lupine is a great model for abscission-related research given that excessive flower abortion reduces its yield. It has been previously shown that the EPIP peptide, a fragment of LlIDL (INFLORESCENCE DEFICIENT IN ABSCISSION) amino-acid sequence, is a sufficient molecule to induce flower abortion, however, the question remains: What are the exact changes evoked by this peptide locally in abscission zone (AZ) cells? Therefore, we used EPIP peptide to monitor specific modifications accompanied by early steps of flower abscission directly in the AZ. EPIP stimulates the downstream elements of the pathway- and MITOGEN-ACTIVATED PROTEIN KINASE6 and induces cellular symptoms indicating AZ activation. The EPIP treatment disrupts redox homeostasis, involving the accumulation of H O and upregulation of the enzymatic antioxidant system including superoxide dismutase, catalase, and ascorbate peroxidase. A weakening of the cell wall structure in response to EPIP is reflected by pectin demethylation, while a changing pattern of fatty acids and acyl lipids composition suggests a modification of lipid metabolism. Notably, the formation of a signaling molecule-phosphatidic acid is induced locally in EPIP-treated AZ. Collectively, all these changes indicate the switching of several metabolic and signaling pathways directly in the AZ in response to EPIP, which inevitably leads to flower abscission.