Jasmonate-Dependent Response of the Flower Abscission Zone Cells to Drought in Yellow Lupine

Abstract

Lipid membranes, as primary places of the perception of environmental stimuli, are a source of various oxygenated polyunsaturated fatty acids—oxylipins—functioning as modulators of many signal transduction pathways, e.g., phytohormonal. Among exogenous factors acting on plant cells, special attention is given to drought, especially in highly sensitive crop species, such as yellow lupine. Here, we used this species to analyze the contribution of lipid-related enzymes and lipid-derived plant hormones in drought-evoked events taking place in a specialized group of cells—the flower abscission zone (AZ)—which is responsible for organ detachment from the plant body. We revealed that water deficits in the soil causes lipid peroxidation in these cells and the upregulation of phospholipase D, lipoxygenase, and, concomitantly, jasmonic acid (JA) strongly accumulates in AZ tissue. Furthermore, we followed key steps in JA conjugation and signaling under stressful conditions by monitoring the level and tissue localization of enzyme providing JA derivatives (JASMONATE RESISTANT1) and the JA receptor (CORONATINE INSENSITIVE1). Collectively, drought-triggered AZ activation during the process of flower abscission is closely associated with the lipid modifications, leading to the formation of JA, its conjugation, and induction of signaling pathways.

Specific Roles of Lipoxygenases in Development and Responses to Stress in Plants

“…The map-based cloning studies disclose that tomato lipoxygenase D ( TomLoxD ), which is a 13-lipoxygenase, catalyzes the biosynthesis of JA [ 21 , 64 , 65 , 66 ]. According to the study of Kućko, et al [ 67 ], oxidative stress-induced lipid peroxidation and subsequent LOX reaction resulted in JA formation in the flower abscission zone cells. Climacteric fruit ripening is a well-regulated (genetically and developmentally) process characterized by several physio-biochemical alterations, including the enhanced rate of ET production, respiration, fruit texture, aroma, flavor, and color [ 68 ].…”

Thidiazuron combined with cyclanilide modulates hormone pathways and ROS systems in cotton, increasing defoliation at low temperatures

“…In this study, compared with the TDZ treatment alone, TDZ combined with CYC increased the expression level of most of the upregulated RBOH genes at 144 h and significantly promoted the accumulation of H 2 O 2 and MDA in the AZs at low temperatures. H 2 O 2 is responsible for maintaining the proper ROS balance in AZs ( Kucko et al., 2022b ), and it regulates cell wall-degrading enzyme gene expression ( Sakamoto et al., 2008a ) and loosens the cell wall in the abscission process. In this study, cell wall hydrolase (PG) genes in AZs were activated by TDZ combined with CYC at the early stage at low temperatures.…”

“…The malondialdehyde (MDA) content was determined using the thiobarbituric acid method (Kucko et al, 2022b). The determination of H 2 O 2 content was determined as described by Li et al (2021).…”