The acceleration of yellow lupine flower abscission by jasmonates is accompanied by lipid-related events in abscission zone cells

• Published in: Plant science (Limerick) Vol. 316; p. 111173
• Main Authors: Kućko, Agata, de Dios Alché, Juan, Tranbarger, Timothy John, Wilmowicz, Emilia
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.03.2022; Elsevier
• Subjects: abscission zone; Acceleration; Cyclopentanes; flower abscission; Flowers; Gene Expression Regulation, Plant; jasmonates; Life Sciences; lipase; lipoxygenase; Lupinus; methyl jasmonate; Oxylipins; Vegetal Biology; PUFA; lipase; APX; PLD; methyl jasmonate; MDA; MeJA; GC-MS; flower abscission; lipoxygenase; LOX; JA; ROS; AZ; jasmonates; abscission zone
• DOI: 10.1016/j.plantsci.2021.111173
• ISSN: 0168-9452

•The process of natural flower separation in lupine involves extensive lipid changes in the abscission zone.•Specific upregulation of oxidative processes related to ascorbate peroxidase are initiated in the abscission zone during flower detachment.•The combined action of lipase and lipoxygenase is triggered during abscission zone activation.•Natural activation of abscission zone cells is closely correlated with the accumulation of jasmonates including methyl jasmonate, which is a stronger accelerator of abscission in lupine than free jasmonic acid. Yellow lupine is an economically important crop. This species has been used as a great model for abscission processes for several years due to extreme flower abortion, which takes place in the abscission zone (AZ). AZ activation involves modifications of cell walls, membranes, and cellular structure. In this paper, we applied physiological, molecular, biochemical, and instrumental methods to explore lipid-associated changes and the possible involvement of lipid-derived phytohormones – jasmonates (JAs) - in flower AZ activation. Our comprehensive analyses revealed that natural abscission is accompanied by the upregulation of peroxidase, which reflects a disruption of redox balance and/or lipids peroxidation in AZ cell membranes. Redox imbalance was confirmed by appearance of malondialdehyde. Lipid-related processes involved the specific localization and increased level and activity of lipase and LOX, enzymes associated with cell membrane rupture, and JA biosynthesis. Lipid-hydrolyzing phospholipase D, implicated previously in abscission, is also found in naturally active AZs. Observed changes are accompanied by the accumulation of jasmonates, both free jasmonic acid and its methyl ester. The JA derivative exhibited higher biological activity than the nonconjugated form. Overall, our study shed new light on the lipid and phytohormonal regulation of AZ functioning supporting a role of JAs during abscission-associated events.