Leaf oil bodies are subcellular factories producing antifungal oxylipins

Shimada, Takashi; Hara‐Nishimura, Ikuko

doi:10.1016/j.pbi.2015.05.019

Cited by 47 publications

(19 citation statements)

References 49 publications

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“…Infection with C.higginsianum induces 2-HOT production and promotes formation of AtCLO3 and α-DOX1-positive OBs in the area around the site of infection. This study provides evidence of leaf OB function in plant defense via production of a phytoalexin under pathological conditions (Shimada et al, 2014;Shimada and Hara-Nishimura, 2015). Thus, the peroxygenase activities of these proteins were involved in the oxylipin signaling pathway and plant defense responses.…”

Section: The Putative Role Of Caleosins In Stress Responsesmentioning

confidence: 65%

New Insights Into the Role of Seed Oil Body Proteins in Metabolism and Plant Development

Shao

Liu

et al. 2019

Front. Plant Sci.

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Oil bodies (OBs) are ubiquitous dynamic organelles found in plant seeds. They have attracted increasing attention recently because of their important roles in plant physiology. First, the neutral lipids stored within these organelles serve as an initial, essential source of energy and carbon for seed germination and post-germinative growth of the seedlings. Secondly, they are involved in many other cellular processes such as stress responses, lipid metabolism, organ development, and hormone signaling. The biological functions of seed OBs are dependent on structural proteins, principally oleosins, caleosins, and steroleosins, which are embedded in the OB phospholipid monolayer. Oleosin and caleosin proteins are specific to plants and mainly act as OB structural proteins and are important for the biogenesis, stability, and dynamics of the organelle; whereas steroleosin proteins are also present in mammals and play an important role in steroid hormone metabolism and signaling. Significant progress using new genetic, biochemical, and imaging technologies has uncovered the roles of these proteins. Here, we review recent work on the structural or metabolic roles of these proteins in OB biogenesis, stabilization and degradation, lipid homeostasis and mobilization, hormone signal transduction, stress defenses, and various aspects of plant growth and development.

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Section: The Putative Role Of Caleosins In Stress Responsesmentioning

confidence: 65%

New Insights Into the Role of Seed Oil Body Proteins in Metabolism and Plant Development

Shao

Liu

et al. 2019

Front. Plant Sci.

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“…Increased PL biosynthesis may be driven by hydrolysis of TG to generate DG and FA, which can then be used as precursors for membrane PL synthesis. The released FA could also provide a source for oxylipin production, as leaf oil bodies have been proposed as subcellular factories for their synthesis (Shimada & Hara‐Nishimura, ). This is supported by the high amount of oxylipin‐related transcripts in EBC, which were highly responsive to salinity (Figure b).…”

Section: Discussionmentioning

confidence: 99%

Single cell‐type analysis of cellular lipid remodelling in response to salinity in the epidermal bladder cells of the model halophyte Mesembryanthemum crystallinum

Barkla

Garibay-Hernández

Melzer

et al. 2018

Plant Cell & Environment

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Salt stress causes dramatic changes in the organization and dynamic properties of membranes, however, little is known about the underlying mechanisms involved. Modified trichomes, known as epidermal bladder cells (EBC), on the leaves and stems of the halophyte Mesembryanthemum crystallinum can be successfully exploited as a single-cell-type system to investigate salt-induced changes to cellular lipid composition. In this study, alterations in key molecular species from different lipid classes highlighted an increase in phospholipid species, particularly those from phosphatidylcholine and phosphatidic acid (PA), where the latter is central to the synthesis of membrane lipids. Triacylglycerol (TG) species decreased during salinity, while there was little change in plastidic galactolipids. EBC transcriptomic and proteomic data mining revealed changes in genes and proteins involved in lipid metabolism and the upregulation of transcripts for PIPKIB, PI5PII, PIPKIII, and phospholipase D delta suggested the induction of signalling processes mediated by phosphoinositides and PA. TEM and flow cytometry showed the dynamic nature of lipid droplets in these cells under salt stress. Altogether, this work indicates that the metabolism of TG might play an important role in EBC response to salinity as either an energy reserve for sodium accumulation and/or driving membrane biosynthesis for EBC expansion.

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“…In fact, diverse proteomic approaches of seed LDs identified proteins involved in lipid metabolism, in particular in TAG mobilization during seed germination, as well as in stress response, intracellular transport, and protein biosynthesis (reviewed in Jolivet et al, 2013). In contrast to the seed LDs, the comprehensive protein composition of leaf LDs remains unresolved and only a few proteins have been described to localize at these compartments (Aubert et al, 2010; Shimada and Hara-Nishimura, 2015). Shimada et al (2014) showed that the caleosin AtCLO3/RD20/PGX3 (At2g33380—thereafter simplified in AtCLO3) interacts with an α-dioxygenase (α-DOX1—At3g01420) in Arabidopsis leaf lipid droplets.…”

Section: Introductionmentioning

confidence: 99%

“…Yet, apart from their role in lipid storage and their implication in the production of an antifungal phytoalexin (Shimada et al, 2014; Shimada and Hara-Nishimura, 2015), little is known about their composition and functions at this developmental stage. Understanding the structure and biogenesis of LDs in senescing leaves will therefore shed new light onto their role in plant aging.…”

Section: Introductionmentioning

confidence: 99%

Proteomic Analysis of Lipid Droplets from Arabidopsis Aging Leaves Brings New Insight into Their Biogenesis and Functions

et al. 2017

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Lipid droplets (LDs) are cell compartments specialized for oil storage. Although their role and biogenesis are relatively well documented in seeds, little is known about their composition, structure and function in senescing leaves where they also accumulate. Here, we used a label free quantitative mass spectrometry approach to define the LD proteome of aging Arabidopsis leaves. We found that its composition is highly different from that of seed/cotyledon and identified 28 proteins including 9 enzymes of the secondary metabolism pathways involved in plant defense response. With the exception of the TRIGALACTOSYLDIACYLGLYCEROL2 protein, we did not identify enzymes implicated in lipid metabolism, suggesting that growth of leaf LDs does not occur by local lipid synthesis but rather through contact sites with the endoplasmic reticulum (ER) or other membranes. The two most abundant proteins of the leaf LDs are the CALEOSIN3 and the SMALL RUBBER PARTICLE1 (AtSRP1); both proteins have structural functions and participate in plant response to stress. CALEOSIN3 and AtSRP1 are part of larger protein families, yet no other members were enriched in the LD proteome suggesting a specific role of both proteins in aging leaves. We thus examined the function of AtSRP1 at this developmental stage and found that AtSRP1 modulates the expression of CALEOSIN3 in aging leaves. Furthermore, AtSRP1 overexpression induces the accumulation of triacylglycerol with an unusual composition compared to wild-type. We demonstrate that, although AtSRP1 expression is naturally increased in wild type senescing leaves, its overexpression in senescent transgenic lines induces an over-accumulation of LDs organized in clusters at restricted sites of the ER. Conversely, atsrp1 knock-down mutants displayed fewer but larger LDs. Together our results reveal that the abundancy of AtSRP1 regulates the neo-formation of LDs during senescence. Using electron tomography, we further provide evidence that LDs in leaves share tenuous physical continuity as well as numerous contact sites with the ER membrane. Thus, our data suggest that leaf LDs are functionally distinct from seed LDs and that their biogenesis is strictly controlled by AtSRP1 at restricted sites of the ER.

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Leaf oil bodies are subcellular factories producing antifungal oxylipins

Cited by 47 publications

References 49 publications

New Insights Into the Role of Seed Oil Body Proteins in Metabolism and Plant Development

New Insights Into the Role of Seed Oil Body Proteins in Metabolism and Plant Development

Single cell‐type analysis of cellular lipid remodelling in response to salinity in the epidermal bladder cells of the model halophyte Mesembryanthemum crystallinum

Proteomic Analysis of Lipid Droplets from Arabidopsis Aging Leaves Brings New Insight into Their Biogenesis and Functions

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