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

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

“…This is reflected by the tissue localization of LOX (Figure 3G,H). We recently observed a similar correlation following the natural activation of lupine AZ [22]. However, in this case, the accumulation of three isoforms (~98, ~100, and ~100 kDa) was noted.…”

“…So, we analyzed the influence of soil drought on the expression, protein level, and localization of LOX in lupine flowers' AZ (Figure 3). The mRNA content of LlLOX2, which was identified recently by us and shown to be involved in AZ functioning [22], increased under water deficit conditions in flower AZ cells (Figure 3A). At the same time, we detected the isoform of LOX protein of ~98 kDa, accumulated strongly in the AZ under drought (Figure 3B,C).…”

“…The involvement of JAs in organ abscission has been already documented in the scientific literature, however, the changes mediated by these phytohormones directly in AZ have not been described so far. The first data regarding this issue in L. luteus, published recently, indicate that JAs are important components of the AZ cells' functioning during the natural processes of flower abscission [22]. In turn, the presented paper is the first to investigate JAs-related events taking place in flower AZ under soil drought stress.…”

“…JA presented in the AZ cells of lupine flowers (Figure 4) might be responsible for the activation of abscission and flower separation, leading to increased water accessibility for other, developing organs. This hypothesis is highly possible given our recent findings suggesting that exogenous JAs applied directly to lupine flower AZ stimulates their abortion, and that the natural abscission of flowers is accompanied by a remarkable accumulation of JA in AZ cells [22].…”

“…Water deficit causes organ AZ activation, leading to extensive, and more importantly, preliminary abortion [19][20][21]. It has been recently pointed out that flower abscission in Lupinus luteus, economically important Fabaceae, is accelerated by JAs and is accompanied by lipid modification specifically in AZ cells [22]. Given that JAs participate in the response of a plant to water deficit, in this paper, we answer a question: whether the soil drought stress can affect the JAs-related events taking place in extremely sensitive tissue-that being flower AZ.…”