@article{baral_typhon_2024,
	title = {{TYPHON} proteins are {RAB}-dependent mediators of the trans-{Golgi} network secretory pathway},
	issn = {1040-4651},
	url = {https://doi.org/10.1093/plcell/koae280},
	doi = {10.1093/plcell/koae280},
	abstract = {The trans-Golgi network (TGN), a key compartment in endomembrane trafficking, participates in both secretion to and endocytosis from the plasma membrane. Consequently, the TGN plays a key role in plant growth and development. Understanding how proteins are sorted for secretion or endocytic recycling at the TGN is critical for elucidating mechanisms of plant development. We previously showed that the protein ECHIDNA is essential for phytohormonal control of hypocotyl bending because it mediates secretion of cell wall components and the auxin influx carrier AUXIN RESISTANT 1 (AUX1) from the TGN. Despite the critical role of ECHIDNA in TGN-mediated trafficking, its mode of action remains unknown in Arabidopsis (Arabidopsis thaliana). We therefore performed a suppressor screen on the ech mutant. Here, we report the identification of TGN-localized TYPHON 1 (TPN1) and TPN2 proteins. A single amino acid change in either TPN protein causes dominant suppression of the ech mutant’s defects in growth and AUX1 secretion, while also restoring wild-type-like ethylene-responsive hypocotyl bending. Importantly, genetic and cell biological evidence shows that TPN1 acts through RAS-ASSOCIATED BINDING H1b (RABH1b), a TGN localized RAB-GTPase. These results provide insights into ECHIDNA-mediated secretory trafficking of cell wall and auxin carriers at the TGN, as well as its role in controlling plant growth.},
	urldate = {2024-10-16},
	journal = {The Plant Cell},
	author = {Baral, Anirban and Gendre, Delphine and Aryal, Bibek and Fougère, Louise and Di Fino, Luciano Martin and Ohori, Chihiro and Sztojka, Bernadette and Uemura, Tomohiro and Ueda, Takashi and Marhavý, Peter and Boutté, Yohann and Bhalerao, Rishikesh P},
	month = oct,
	year = {2024},
	pages = {koae280},
}

The trans-Golgi network (TGN), a key compartment in endomembrane trafficking, participates in both secretion to and endocytosis from the plasma membrane. Consequently, the TGN plays a key role in plant growth and development. Understanding how proteins are sorted for secretion or endocytic recycling at the TGN is critical for elucidating mechanisms of plant development. We previously showed that the protein ECHIDNA is essential for phytohormonal control of hypocotyl bending because it mediates secretion of cell wall components and the auxin influx carrier AUXIN RESISTANT 1 (AUX1) from the TGN. Despite the critical role of ECHIDNA in TGN-mediated trafficking, its mode of action remains unknown in Arabidopsis (Arabidopsis thaliana). We therefore performed a suppressor screen on the ech mutant. Here, we report the identification of TGN-localized TYPHON 1 (TPN1) and TPN2 proteins. A single amino acid change in either TPN protein causes dominant suppression of the ech mutant’s defects in growth and AUX1 secretion, while also restoring wild-type-like ethylene-responsive hypocotyl bending. Importantly, genetic and cell biological evidence shows that TPN1 acts through RAS-ASSOCIATED BINDING H1b (RABH1b), a TGN localized RAB-GTPase. These results provide insights into ECHIDNA-mediated secretory trafficking of cell wall and auxin carriers at the TGN, as well as its role in controlling plant growth.

@article{hermida-carrera_cdk8_2024,
	title = {{CDK8} of the mediator kinase module connects leaf development to the establishment of correct stomata patterning by regulating the levels of the transcription factor {SPEECHLESS} ({SPCH})},
	volume = {n/a},
	copyright = {© 2024 The Author(s). Plant, Cell \& Environment published by John Wiley \& Sons Ltd.},
	issn = {1365-3040},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/pce.15102},
	doi = {10.1111/pce.15102},
	abstract = {The components of the mediator kinase module are highly conserved across all eukaryotic lineages, and cyclin-dependent kinase 8 (CDK8) is essential for correct cell proliferation and differentiation in diverse eukaryotic systems. We show that CDK8 couples leaf development with the establishment of correct stomata patterning for prevailing CO2 conditions. In Arabidopsis, the basic helix-loop-helix (bHLH) transcription factor SPEECHLESS (SPCH) controls cellular entry into the stomatal cell lineage, and CDK8 interacts with and phosphorylates SPCH, controlling SPCH protein levels and thereby also expression of the SPCH target genes encoding key regulators of cell fate and asymmetric cell divisions. The lack of the CDK8-mediated control of SPCH results in an increased number of meristemoid and guard mother cells, and increased stomata index in the cdk8 mutants. Increasing atmospheric CO2 concentrations trigger a developmental programme controlling cell entry into stomatal lineage by limiting the asymmetric divisions. In cdk8, the number of meristemoids and guard mother cells remains the same under ambient and high CO2 concentrations, as the accumulated levels of SPCH caused by the lack of CDK8 appear to override the negative regulation of increased CO2. Thus, our work provides novel mechanistic understanding of how plants alter critical leaf properties in response to increasing atmospheric CO2.},
	language = {en},
	number = {n/a},
	urldate = {2024-08-30},
	journal = {Plant, Cell \& Environment},
	author = {Hermida-Carrera, Carmen and Vergara, Alexander and Cervela-Cardona, Luis and Jin, Xu and Björklund, Stefan and Strand, Åsa},
	year = {2024},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/pce.15102},
	keywords = {CO2 response, climate change, drought},
}

The components of the mediator kinase module are highly conserved across all eukaryotic lineages, and cyclin-dependent kinase 8 (CDK8) is essential for correct cell proliferation and differentiation in diverse eukaryotic systems. We show that CDK8 couples leaf development with the establishment of correct stomata patterning for prevailing CO2 conditions. In Arabidopsis, the basic helix-loop-helix (bHLH) transcription factor SPEECHLESS (SPCH) controls cellular entry into the stomatal cell lineage, and CDK8 interacts with and phosphorylates SPCH, controlling SPCH protein levels and thereby also expression of the SPCH target genes encoding key regulators of cell fate and asymmetric cell divisions. The lack of the CDK8-mediated control of SPCH results in an increased number of meristemoid and guard mother cells, and increased stomata index in the cdk8 mutants. Increasing atmospheric CO2 concentrations trigger a developmental programme controlling cell entry into stomatal lineage by limiting the asymmetric divisions. In cdk8, the number of meristemoids and guard mother cells remains the same under ambient and high CO2 concentrations, as the accumulated levels of SPCH caused by the lack of CDK8 appear to override the negative regulation of increased CO2. Thus, our work provides novel mechanistic understanding of how plants alter critical leaf properties in response to increasing atmospheric CO2.

@article{lin_tree-ring_2024,
	title = {A tree-ring cellulose extraction device adapted to radiocarbon analysis},
	issn = {0033-8222, 1945-5755},
	url = {https://www.cambridge.org/core/journals/radiocarbon/article/treering-cellulose-extraction-device-adapted-to-radiocarbon-analysis/7B981240F489EAC06325D1CA83798579},
	doi = {10.1017/RDC.2024.83},
	abstract = {Tree-ring cellulose is a commonly used material for radiocarbon analysis. Extracting cellulose is labor-consuming and several devices that enable batchwise extraction have been developed. However, these devices bear the risk of sample contamination. The present study describes a new device which improves upon two aspects of currently available devices. First, to prevent cross-sample-contamination, we redesigned the drainage module to enable independent removal of chemical waste from each individual sample funnel. Second, we added covers to the sample funnels to reduce the risk of external contamination. Cellulose purity (i.e., holocellulose) was confirmed by Fourier Transform Infrared (FTIR) Spectroscopy. Furthermore, accuracy of the radiocarbon analysis was confirmed by results of 14C-blank samples and samples of known age. In conclusion, while maintaining labor-saving, our modified device significantly reduces the risk of sample contamination during extraction of tree-ring cellulose.},
	language = {en},
	urldate = {2024-10-11},
	journal = {Radiocarbon},
	author = {Lin, Pengyu and Zhao, Yesi and Zhang, Hongyan and Wieloch, Thomas and Gu, Yao and Liang, Chenghong and Chen, Feng and Lu, Huayu},
	month = sep,
	year = {2024},
	keywords = {cellulose extraction, dendrochronology, radiocarbon analysis, tree-ring analysis},
	pages = {1--10},
}

Tree-ring cellulose is a commonly used material for radiocarbon analysis. Extracting cellulose is labor-consuming and several devices that enable batchwise extraction have been developed. However, these devices bear the risk of sample contamination. The present study describes a new device which improves upon two aspects of currently available devices. First, to prevent cross-sample-contamination, we redesigned the drainage module to enable independent removal of chemical waste from each individual sample funnel. Second, we added covers to the sample funnels to reduce the risk of external contamination. Cellulose purity (i.e., holocellulose) was confirmed by Fourier Transform Infrared (FTIR) Spectroscopy. Furthermore, accuracy of the radiocarbon analysis was confirmed by results of 14C-blank samples and samples of known age. In conclusion, while maintaining labor-saving, our modified device significantly reduces the risk of sample contamination during extraction of tree-ring cellulose.

@article{vishwakarma_pisolithus_2024,
	title = {\textit{{Pisolithus} microcarpus} isolates with contrasting abilities to colonise \textit{{Eucalyptus} grandis} exhibit significant differences in metabolic signalling},
	volume = {128},
	issn = {1878-6146},
	url = {https://www.sciencedirect.com/science/article/pii/S1878614624001247},
	doi = {10.1016/j.funbio.2024.09.001},
	abstract = {Biotic factors in fungal exudates impact plant-fungal symbioses establishment. Mutualistic ectomycorrhizal fungi play various ecological roles in forest soils by interacting with trees. Despite progress in understanding secreted fungal signals, dynamics of signal production in situ before or during direct host root contact remain unclear. We need to better understand how variability in intra-species fungal signaling at these stages impacts symbiosis with host tissues. Using the ECM model Pisolithus microcarpus, we selected two isolates (Si9 and Si14) with different abilities to colonize Eucalyptus grandis roots. Hypothesizing that distinct early signalling and metabolite profiles between these isolates would influence colonization and symbiosis, we used microdialysis to non-destructively collect secreted metabolites from either the fungus, host, or both, capturing the dynamic interplay of pre-symbiotic signalling over 48 hours. Our findings revealed significant differences in metabolite profiles between Si9 and Si14, grown alone or with a host root. Si9, with lower colonization efficiency than Si14, secreted a more diverse range of compounds, including lipids, oligopeptides, and carboxylic acids. In contrast, Si14's secretions, similar to the host's, included more aminoglycosides. This study emphasizes the importance of intra-specific metabolomic diversity in ectomycorrhizal fungi, suggesting that early metabolite secretion is crucial for establishing successful mutualistic relationships.},
	number = {7},
	urldate = {2024-10-11},
	journal = {Fungal Biology},
	author = {Vishwakarma, Kanchan and Buckley, Scott and Plett, Jonathan M. and Lundberg-Felten, Judith and Jämtgård, Sandra and Plett, Krista L.},
	month = nov,
	year = {2024},
	keywords = {Ectomycorrhizal fungi, Eucalyptus, Indirect contact, Isolates, Metabolites, Microdialysis system},
	pages = {2157--2166},
}

Biotic factors in fungal exudates impact plant-fungal symbioses establishment. Mutualistic ectomycorrhizal fungi play various ecological roles in forest soils by interacting with trees. Despite progress in understanding secreted fungal signals, dynamics of signal production in situ before or during direct host root contact remain unclear. We need to better understand how variability in intra-species fungal signaling at these stages impacts symbiosis with host tissues. Using the ECM model Pisolithus microcarpus, we selected two isolates (Si9 and Si14) with different abilities to colonize Eucalyptus grandis roots. Hypothesizing that distinct early signalling and metabolite profiles between these isolates would influence colonization and symbiosis, we used microdialysis to non-destructively collect secreted metabolites from either the fungus, host, or both, capturing the dynamic interplay of pre-symbiotic signalling over 48 hours. Our findings revealed significant differences in metabolite profiles between Si9 and Si14, grown alone or with a host root. Si9, with lower colonization efficiency than Si14, secreted a more diverse range of compounds, including lipids, oligopeptides, and carboxylic acids. In contrast, Si14's secretions, similar to the host's, included more aminoglycosides. This study emphasizes the importance of intra-specific metabolomic diversity in ectomycorrhizal fungi, suggesting that early metabolite secretion is crucial for establishing successful mutualistic relationships.

@article{baba_cell_2024,
	title = {Cell adhesion maintenance and controlled separation in plants},
	volume = {2},
	issn = {2813-821X},
	url = {https://www.frontiersin.org/journals/plant-physiology/articles/10.3389/fphgy.2024.1369575/full},
	doi = {10.3389/fphgy.2024.1369575},
	abstract = {{\textless}p{\textgreater}Cell-cell adhesion is a fundamental aspect of maintaining multicellular integrity while ensuring controlled cell and organ shedding, intercellular space formation and intrusive growth. Understanding of the precise mechanisms governing regulated cell separation, such as abscission, considerably progressed in recent decades. However, our comprehension of how plants maintain adhesion within tissues in which it is essential remains limited. Here we review some of the well-established knowledge along with latest discoveries that lead us to rethink the way developmentally controlled cell separation and adhesion maintenance may work. We also specifically explore the relationship between growth and adhesion, highlighting their similarities and coupling, and propose a plausible framework in which growth and adhesion are tightly co-regulated.{\textless}/p{\textgreater}},
	language = {English},
	urldate = {2024-10-09},
	journal = {Frontiers in Plant Physiology},
	author = {Baba, Abu Imran and Verger, Stéphane},
	month = feb,
	year = {2024},
	note = {Publisher: Frontiers},
	keywords = {Abscission, Adhesion, Cell Wall, Growth, SEPARATION},
}

\textlessp\textgreaterCell-cell adhesion is a fundamental aspect of maintaining multicellular integrity while ensuring controlled cell and organ shedding, intercellular space formation and intrusive growth. Understanding of the precise mechanisms governing regulated cell separation, such as abscission, considerably progressed in recent decades. However, our comprehension of how plants maintain adhesion within tissues in which it is essential remains limited. Here we review some of the well-established knowledge along with latest discoveries that lead us to rethink the way developmentally controlled cell separation and adhesion maintenance may work. We also specifically explore the relationship between growth and adhesion, highlighting their similarities and coupling, and propose a plausible framework in which growth and adhesion are tightly co-regulated.\textless/p\textgreater