Electron microscopy for imaging organelles in plants and algae

PLANT PHYSIOLOGY, Journal Year: 2021, Volume and Issue: 188(2), P. 713 - 725

Published: Sept. 18, 2021

Abstract Recent developments in both instrumentation and image analysis algorithms have allowed three-dimensional electron microscopy (3D-EM) to increase automated collections through large tissue volumes using serial block-face scanning EM (SEM) achieve near-atomic resolution of macromolecular complexes cryo-electron tomography (cryo-ET) sub-tomogram averaging. In this review, we discuss applications cryo-ET cell biology research on plant algal systems the special opportunities they offer for understanding organization eukaryotic organelles with unprecedently resolution. However, one most challenging aspects is sample preparation, especially multicellular organisms. We also correlative light (CLEM) approaches that been developed ET at room cryogenic temperatures.

Language: Английский

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A glossary of plant cell structures: Current insights and future questions

The Plant Cell, Journal Year: 2021, Volume and Issue: 34(1), P. 10 - 52

Published: Oct. 8, 2021

Abstract In this glossary of plant cell structures, we asked experts to summarize a present-day view organelles and including discussion outstanding questions. the following short reviews, authors discuss complexities endomembrane system, exciting connections between organelles, novel insights into peroxisome structure function, dynamics mitochondria, mysteries that need be unlocked from wall. These discussions are focused through lens new microscopy techniques. Advanced imaging has uncovered unexpected shapes, dynamics, intricate membrane formations. With continued focus in next decade, these modalities coupled with functional studies sure begin unravel cell.

Language: Английский

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Autophagy and its mediated mitochondrial quality control maintain pollen tube growth and male fertility in Arabidopsis

Autophagy, Journal Year: 2022, Volume and Issue: 19(3), P. 768 - 783

Published: July 4, 2022

Macroautophagy/autophagy, a major catabolic pathway in eukaryotes, participates plant sexual reproduction including the processes of male gametogenesis and self-incompatibility response. Rapid pollen tube growth is another essential reproductive process that metabolically highly demanding to drive vigorous cell for delivery gametes fertilization angiosperms. Whether how autophagy operates maintain homeostasis tubes remains unknown. Here, we provide evidence elevated growing critically required during fertility Arabidopsis. We demonstrate SH3P2, critical non-ATG regulator autophagy, colocalizes with representative ATG proteins autophagosome biogenesis tubes. Downregulation SH3P2 expression significantly disrupts Arabidopsis germination growth. Further analysis organelle dynamics reveals crosstalk between autophagosomes prevacuolar compartments following inhibition phosphatidylinositol 3-kinase. In addition, time-lapse imaging tracking ATG8e-labeled depolarized mitochondria they interact specifically via ATG8-family interacting motif (AIM)-docking site mediate mitophagy. Ultrastructural identification mitophagosomes two additional forms imply multiple types are likely function simultaneously within Altogether, our results suggest functionally crucial mediating mitochondrial quality control canonical cytoplasm recycling growth.Abbreviations: AIM: motif; ATG8: related 8; ATG5: 5; ATG7: 7; BTH: acibenzolar-S-methyl; DEX: dexamethasone; DNP: 2,4-dinitrophenol; GFP: green fluorescent protein; YFP: yellow PtdIns3K: 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PVC: compartment; SH3P2: SH3 domain-containing protein 2.

Language: Английский

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Mitophagy in plants: Emerging regulators of mitochondrial targeting for selective autophagy

Journal of Microscopy, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 31, 2024

Abstract The degradation and turnover of mitochondria is fundamental to Eukaryotes a key homeostatic mechanism for maintaining functional mitochondrial populations. Autophagy an important pathway by which are degraded, involving their sequestration into membrane‐bound autophagosomes targeting lytic endosomal compartments (the lysosome in animals, the vacuole plants yeast). Selective autophagy, also known as mitophagy, distinguishes from other cell components necessary regulation mitochondria‐specific processes. In mammals yeast, mitophagy has been well characterised regulated numerous pathways with diverse functions homeostasis, metabolism responses specific stresses. contrast, we only just beginning understand importance plants, chiefly proteins that target autophagy recently emerging. Here, discuss current progress our understanding plant life regulatory involved degradation. particular, will recent emergence receptor selectively missing links knowledge mitophagy‐regulatory compared animals yeast.

Language: Английский

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Autophagosome biogenesis and organelle homeostasis in plant cells

The Plant Cell, Journal Year: 2024, Volume and Issue: 36(9), P. 3009 - 3024

Published: March 27, 2024

Autophagy is one of the major highly inducible degradation processes in response to plant developmental and environmental signals. In different stimuli, cellular materials, including proteins organelles, can be sequestered into a double membrane autophagosome structure either selectively or nonselectively. The formation an as well its delivery vacuole involves complex dynamic processes. identification characterization conserved autophagy-related (ATG) their related regulators have greatly advanced our understanding molecular mechanism underlying biogenesis function cells. Autophagosome tightly regulated by coordination multiple ATG non-ATG selective cargo recruitment. This review updates current knowledge biogenesis, with special emphasis on core machinery that drives autophagosome-organelle interactions under abiotic stress conditions.

Language: Английский

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Autophagy in plants

Autophagy Reports, Journal Year: 2024, Volume and Issue: 3(1)

Published: Oct. 15, 2024

Autophagy is a process of cellular self-eating, which allows organisms to eliminate and recycle unwanted components damaged organelles maintain homeostasis. It an important in the development eukaryotic organisms. plays critical role many physiological processes plants such as nutrient remobilization, cell death, immunity, abiotic stress responses. thus represents obvious target for generating resilient crops. During plant development, autophagy also implicated differentiation maturation various types organs, including root cap cells, tracheary elements, gametes, fruits seeds. Here, we review our current understanding recent advances insight into regulation signaling well autophagosome membrane biogenesis. In addition, describe how contributes metabolism, biotic tolerance where autophagic field heading terms applied research crop improvement.

Language: Английский

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Carbon starvation, senescence and specific mitochondrial stresses, but not nitrogen starvation and general stresses, are major triggers for mitophagy in Arabidopsis

Autophagy, Journal Year: 2022, Volume and Issue: 18(12), P. 2894 - 2912

Published: March 20, 2022

Selective degradation of mitochondria by autophagy (mitophagy) is thought to play an important role in mitochondrial quality control, but our understanding which conditions induce mitophagy plants limited. Here, we developed novel reporter lines monitor and surveyed the rate under a wide range stresses developmental conditions. Especially carbon starvation induced dark-incubation causes dramatic increase within few hours, further increasing as dark-induced senescence progresses. Natural was also strong trigger mitophagy, peaking when leaf yellowing became prominent. In contrast, nitrogen starvation, general autophagy, does not increases mitophagy. Similarly, such hydrogen peroxide, heat, UV-B hypoxia did appear substantial plants. Additionally, exposed inhibitors electron transport chain, translation protein import. Although short-term treatments high rates, longer term exposures uncoupling agent import/translation could clearly mitophagic flux. These findings be confirmed using confocal microscopy. To validate that mediated pathway, showed flux abolished or strongly decreased atg5/AuTophaGy 5 atg11 mutants, respectively. Finally, observed rates etiolated seedlings, remarkably completely repressed 6 h after light exposure. conclusion, propose natural specific are key triggers plants.Abbreviations: AA: antimycin A; ATG: AuToPhagy related; ConA: concanamycin DIS: senescence; Dox: doxycycline; FCCP: carbonyl cyanide-p-trifluoromethoxyphenylhydrazone; GFP: green fluorescent protein; IDH1: isocitrate dehydrogenase 1; MB: MitoBlock-6; Mito-GFP: transgenic Arabidopsis line expressing mitochondrially targeted fused GFP; mtETC: chain; OXPHOS: oxidative phosphorylation; PQC: control; TOM20: Translocase Outer Membrane 20.

Language: Английский

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The interplay between autophagy and chloroplast vesiculation pathways under dark‐induced senescence

Plant Cell & Environment, Journal Year: 2023, Volume and Issue: 46(12), P. 3721 - 3736

Published: Aug. 24, 2023

In cellular circumstances where carbohydrates are scarce, plants can use alternative substrates for energetic maintenance. plants, the main protein reserve is present in chloroplast, which contains most of total leaf proteins and represents a rich source nitrogen amino acids. Autophagy plays key role chloroplast breakdown, well-recognised symptom both natural stress-induced plant senescence. Remarkably, an autophagic-independent route degradation associated with vesiculation (CV) gene was previously demonstrated. During extended darkness, CV highly induced absence autophagy, contributing to early senescence phenotype atg mutants. To further investigate under dark-induced conditions, mutants low expression (amircv) double amircv1xatg5 were characterised. Following darkness treatment, no aberrant phenotypes observed amircv single mutants; however, displayed altered dismantling membrane structures these conditions. Metabolic characterisation revealed that functional lack autophagy leads higher impairment acid release differential organic accumulation during starvation The data obtained discussed context terms metabolism regulation degradation.

Language: Английский

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The strange case of Drp1 in autophagy: Jekyll and Hyde?

BioEssays, Journal Year: 2022, Volume and Issue: 44(4)

Published: Feb. 15, 2022

Abstract There is a debate regarding the function of Drp1, GTPase involved in mitochondrial fission, during elimination mitochondria by autophagy. A number experiments indicate that Drp1 needed to eliminate mitophagy, either reducing size or providing noncanonical mitophagy function. Yet, other convincing experimental results support conclusion not necessary. Here, we review possible functions for and autophagy, depending on tissues, organisms stresses, discuss these apparent discrepancies. In this regard, it appears reduction often required but always Drp1‐dependent manner. Finally, speculate Drp1‐independent fission mechanism may take place roles, which play such as modulating organelle contact sites dynamic autophagosome formation.

Language: Английский

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Altered collective mitochondrial dynamics in the Arabidopsismsh1mutant compromising organelle DNA maintenance

Journal of Experimental Botany, Journal Year: 2022, Volume and Issue: 73(16), P. 5428 - 5439

Published: June 5, 2022

Abstract Mitochondria form highly dynamic populations in the cells of plants (and almost all eukaryotes). The characteristics and benefits this collective behaviour, how it is influenced by nuclear features, remain to be fully elucidated. Here, we use a recently developed quantitative approach reveal analyse physical ‘social’ dynamics mitochondria an Arabidopsis msh1 mutant where organelle DNA maintenance machinery compromised. We newly created line combining with mitochondrially targeted green fluorescent protein (GFP), characterize mitochondrial combination single-cell time-lapse microscopy, computational tracking, network analysis. behaviour altered from that wild type several ways: become less evenly spread, networks inter-mitochondrial encounters more connected, greater potential efficiency for inter-organelle exchange—reflecting compensatory mechanism genetic challenge population, supporting exchange. find these changes are similar those observed friendly, perturbation, suggesting shift higher connectivity may reflect general response challenges, control structure mtDNA population.

Language: Английский

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