Capping Protein Modulates Actin Remodeling in Response to Reactive Oxygen Species during Plant Innate Immunity

Li, Jiejie; Cao, Lingyan; Staiger, Christopher J.

doi:10.1104/pp.16.00992

Cited by 51 publications

(73 citation statements)

References 83 publications

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“…We next sought to explore the physiological or pathological significance of the unique profilin isoform AtPRF3 in Arabidopsis. Actin filament assembly plays essential roles in polarized growth and defensive responses during plant-pathogen interactions [9,[30][31][32][33][34][35]. How do profilin/formin/actin complexes, as the key actin assembly module, regulate polarized cell growth and innate immunity during plant defensive responses, particularly with AtPRF3, remains elusive.…”

Section: Atprf3 Is Highly Involved In Arabidopsis Innate Immune Respomentioning

confidence: 99%

Profilin Negatively Regulates Formin-Mediated Actin Assembly to Modulate PAMP-Triggered Plant Immunity

et al. 2018

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Profilin functions with formin in actin assembly, a process that regulates multiple aspects of plant development and immune responses. High-level eukaryotes contain multiple isoforms of profilin, formin, and actin, whose partner-specific interactions in actin assembly are not completely understood in plant development and defense responses. To examine the functionally distinct interactions between profilin and formin, we studied all five Arabidopsis profilins and their interactions with formin by using both in vitro biochemical and in vivo cell biology approaches. Unexpectedly, we found a previously undescribed negative regulatory function of AtPRF3 in AtFH1-mediated actin polymerization. The N-terminal 37 residues of AtPRF3 were identified to play a predominant role in inhibiting formin-mediated actin nucleation via their high affinity for the formin polyproline region and their triggering of the oligomerization of AtPRF3. Both in vivo and in vitro mechanistic studies of AtPRF3 revealed a universal mechanism in which the weak interaction between profilin and formin positively regulates actin assembly by ensuring rapid recycling of profilin, whereas profilin oligomerization negatively regulates actin polymerization. Upon recognition of the pathogen-associated molecular pattern, the gene transcription and protein degradation of AtPRF3 are modulated for actin assembly during plant innate immunity. The prf3 Arabidopsis plants show higher sensitivity to the bacterial flagellum peptide in both the plant growth and ROS responses. These findings demonstrate a profilin-mediated actin assembly mechanism underlying the plant immune responses.

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Section: Atprf3 Is Highly Involved In Arabidopsis Innate Immune Respomentioning

confidence: 99%

Profilin Negatively Regulates Formin-Mediated Actin Assembly to Modulate PAMP-Triggered Plant Immunity

et al. 2018

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“…Mlo (Mildew resistance locus O) and RAC/ROP family G‐protein RACB knockdown plants showed polarized actin filaments towards the attempted penetration site of Bgh and increased defense against Bgh (Schultheiss et al ., ; Opalski et al ., ). Actin capping proteins appear to be crucial to the actin‐based immune response, allowing for ROS‐induced remodeling during innate immunity (Li et al ., ), and modulating the actin response to various PAMP pathways, such as chitin, flg22 and elf26 (Li et al ., ). Considering the importance of AFs in immunity, it is not surprising that pathogen effectors disrupt AFs (Table ).…”

Section: The Cytoskeleton In Plant–microbe Interactionsmentioning

confidence: 99%

Plant–microbe interactions: organelles and the cytoskeleton in action

et al. 2017

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Contents Summary1012I.Introduction1012II.The endomembrane system in plant–microbe interactions1013III.The cytoskeleton in plant–microbe interactions1017IV.Organelles in plant–microbe interactions1019V.Inter‐organellar communication in plant–microbe interactions1022VI.Conclusions and prospects1023Acknowledgements1024References1024 Summary Plants have evolved a multilayered immune system with well‐orchestrated defense strategies against pathogen attack. Multiple immune signaling pathways, coordinated by several subcellular compartments and interactions between these compartments, play important roles in a successful immune response. Pathogens use various strategies to either directly attack the plant's immune system or to indirectly manipulate the physiological status of the plant to inhibit an immune response. Microscopy‐based approaches have allowed the direct visualization of membrane trafficking events, cytoskeleton reorganization, subcellular dynamics and inter‐organellar communication during the immune response. Here, we discuss the contributions of organelles and the cytoskeleton to the plant's defense response against microbial pathogens, as well as the mechanisms used by pathogens to target these compartments to overcome the plant's defense barrier.

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“…i,j). Increased bundles and higher density were similar to those observed in plant cells challenged with bacterial pathogens or pathogen‐associated molecular patterns (Day et al ., ; Shimono et al ., ; Li et al ., ). The appearance of such changes in stages I and II were consistent with the entry and release of the rhizobia into the inner cells, respectively (Fig.…”

Section: Discussionmentioning

confidence: 97%

The host actin cytoskeleton channels rhizobia release and facilitates symbiosome accommodation during nodulation in Medicago truncatula

et al. 2018

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In plants, the actin cytoskeleton plays a central role in regulating intracellular transport and trafficking in the endomembrane system. Work in legumes suggested that during nodulation, the actin cytoskeleton coordinates numerous cellular processes in the development of nitrogen-fixing nodules. However, we lacked live-cell visualizations demonstrating dynamic remodeling of the actin cytoskeleton during infection droplet release and symbiosome development. Here, we generated transgenic Medicago truncatula lines stably expressing the fluorescent actin marker ABD2-GFP, and utilized live-cell imaging to reveal the architecture and dynamics of the actin cytoskeleton during nodule development. Live-cell observations showed that different zones in nitrogen-fixing nodules exhibit distinct actin architectures and infected cells display five characteristic actin architectures during nodule development. Live-cell imaging combined with three-dimensional reconstruction demonstrated that dense filamentous-actin (F-actin) arrays channel the elongation of infection threads and the release of infection droplets, an F-actin network encircles freshly-released rhizobia, and short F-actin fragments and actin dots around radially distributed symbiosomes. Our findings suggest an important role of the actin cytoskeleton in infection droplet release, symbiosome development and maturation, and provide significant insight into the cellular mechanisms underlying nodule development and nitrogen fixation during legume-rhizobia interactions.

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Capping Protein Modulates Actin Remodeling in Response to Reactive Oxygen Species during Plant Innate Immunity

Cited by 51 publications

References 83 publications

Profilin Negatively Regulates Formin-Mediated Actin Assembly to Modulate PAMP-Triggered Plant Immunity

Profilin Negatively Regulates Formin-Mediated Actin Assembly to Modulate PAMP-Triggered Plant Immunity

Plant–microbe interactions: organelles and the cytoskeleton in action

The host actin cytoskeleton channels rhizobia release and facilitates symbiosome accommodation during nodulation in Medicago truncatula

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