The hydroperoxide lyase branch of the oxylipin pathway protects against photoinhibition of photosynthesis

Abstract

This study describes a new role for hydroperoxide lyase branch of oxylipin biosynthesis pathway in protecting photosynthetic apparatus under high light conditions. Lipid-derived signaling molecules, oxylipins, produced by a multi-branch pathway are central in regulation of a wide range of functions. The two most known branches, allene oxide synthase (AOS) and 13-hydroperoxide lyase (HPL) pathways, are best recognized as producers of defense compounds against biotic challenges. In the present work, we examine the role of these two oxylipin branches in plant tolerance to the abiotic stress, namely excessive light. Towards this goal, we have analyzed variable chlorophyll fluorescence parameters of intact leaves of Arabidopsis thaliana genotypes with altered oxylipin profile, followed by examining the impact of exogenous application of selected oxylipins on functional activity of photosynthetic apparatus in intact leaves and isolated thylakoid membranes. Our findings unequivocally bridge the function of oxylipins to photosynthetic processes. Specifically, HPL overexpressing lines display enhanced adaptability in response to high light treatment as evidenced by lower rate constant of photosystem 2 (PS2) photoinhibition and higher rate constant of PS2 recovery after photoinhibition. In addition, exogenous application of linolenic acid, 13-hydroperoxy linolenic acid, 12-oxophytodienoic acid, and methyl jasmonate individually, suppresses photochemical activity of PS2 in intact plants and isolated thylakoid membranes, while application of HPL-branch metabolites-does not. Collectively these data implicate function of HPL branch of oxylipin biosynthesis pathway in guarding PS2 under high light conditions, potentially exerted through tight regulation of free linolenic acid and 13-hydroperoxy linolenic acid levels, as well as competition with production of metabolites by AOS-branch of the oxylipin pathway.

The Main Structural and Functional Characteristics of Photosystem-II-Enriched Membranes Isolated from Wild Type and cia3 Mutant Chlamydomonas reinhardtii

“…Both values were consistent with our previously published data [40]. Additionally, the maximum quantum yield of PSII (F v /F m ), which indicates the maximum photochemical efficiency of PSII [55,56], was estimated. The obtained F v /F m values were the same for PSII from both WT and cia3 (Figure 4B) and was near 0.65.…”

Identification of differentially expressed genes in flower, leaf and bulb scale of Lilium oriental hybrid ‘Sorbonne’ and putative control network for scent genes

“…All verified genes except HPL had higher expression level in flower than in leaf and scale. A very recent study revealed HPL involvement in protecting the photosynthetic apparatus [ 52 ]. We deduce that this gene may play an important role in lily leaf and further functional studies are required to understand its role in lily leaf and flower.…”

Overexpression of Arabidopsis OPR3 in Hexaploid Wheat (Triticum aestivum L.) Alters Plant Development and Freezing Tolerance

“…Unfavorable environmental conditions affect wheat crop yield globally [7]; therefore, the improvement of wheat tolerance to environmental stresses is of particular importance. The modification of individual steps of oxylipin biosynthesis pathway results in the alteration of plant tolerance to environmental challenges, as shown for Arabidopsis [8,9,10,11,12] and other species, including a few monocots [6,13,14]. For wheat, a protective effect of exogenously applied jasmonates under conditions of biotic and abiotic stresses was demonstrated in numerous studies [15,16,17], suggesting that the modulation of the activity of jasmonate-based signaling systems is a promising approach for the improvement of wheat tolerance to environmental stresses.…”