Arabidopsis lipoxygenase 2 is essential for formation of green leaf volatiles and five‐carbon volatiles

Abstract

Plants biosynthesize a variety of bioactive lipid derivatives, such as green leaf volatiles (GLVs) and jasmonates (JAs). Here we identify a lipoxygenase 2 (LOX2) involved in GLV biosynthesis in Arabidopsis using mutant lines for each of the six LOX isoforms present in Arabidopsis. We found that formation of five carbon volatiles was also dependent on LOX2. LOX2 is known to be involved in formation of JA; thus, LOX2 is apparently versatile in function. The results in this study suggested that LOX2 activity is suppressed in intact cells but activated upon tissue damage to support the rapid GLV‐burst observed in wounded leaves.

Green leaf volatile production by plants: a meta‐analysis

“…As stated by Mochizuki et al . () there are two ways to accomplish this. First, by a distinct spatiotemporal expression of HPL and AOS (Mwenda et al ., ), and, second, by expression of pathway‐specific LOXs.…”

“…First, by a distinct spatiotemporal expression of HPL and AOS (Mwenda et al ., ), and, second, by expression of pathway‐specific LOXs. While some plant species possess pathway‐specific LOXs that feed 13‐HPs either into the AOS branch alone, leading to the formation of JA, or into the HPL branch, leading to the formation of GLVs (Allmann et al ., ; Christensen et al ., ), other plant species have LOXs that can supply substrate to both pathways (Wang et al ., ; Mochizuki et al ., ). Competitive substrate flux into the AOS and HP branches has already been reported for several plant species by silencing or overexpression of the HPL/AOS pathways (Halitschke et al ., ; Liu et al ., ; Tong et al ., ; Xin et al ., ).…”

“…Because of the shared substrate, plants need to distinctly regulate GLV and JA biosynthesis. As stated by Mochizuki et al (2016) there are two ways to accomplish this. First, by a distinct spatiotemporal expression of HPL and AOS (Mwenda et al, 2015), and, second, by expression of pathway-specific LOXs.…”

The activity of HYDROPEROXIDE LYASE 1 regulates accumulation of galactolipids containing 12-oxo-phytodienoic acid in Arabidopsis

“…Interestingly, the authors could detect significant amounts of MGDG containing 7-OH-dinortraumatin and/or 9-OH-traumatin after tissue disruption in several plant species that are reportedly unable to synthesize arabidopsides. Furthermore, synthesis of the majority of the six carbon volatiles via HPL in Arabidopsis have been shown to be dependent on LOX2 activity (Mochizuki et al , 2016). Taken together, this and other studies provide strong evidence that HPL can access lipid-bound hydroperoxides fatty acids in a number of plant species.…”

Transcriptomic response in symptomless roots of clubroot infected kohlrabi (Brassica oleracea var. gongylodes) mirrors resistant plants

“…Among JA-543 metabolism genes HPL, and LOX2 expression were up-regulated in the galls. LOX2 is 544 essential for the formation of oxylipin volatiles (Mochizuki et al, 2016). The HPL 545 protein competes with substrates essential for JA-synthesis, producing volatile and non-546 volatile oxylipins (Wasternack and Hause, 2013).…”