Biology subjects

Van Damme, D.

Publications and source records attributed to Van Damme, D..

At least 19 recordsLinked to original sources

bioRxiv2026

Synaptotagmin-mediated plasma membrane homeostasis is required to recruit the endocytic machinery during cold stress

Endocytosis depends on plasma membrane (PM) lipid composition, yet how plants sustain endocytic machinery recruitment during stress remains unclear. We investigated whether synaptotagmins SYT1 and SYT3 function in membrane homeostasis and endocytosis in Arabidopsis thaliana. In this work, we revealed that cold stress reversibly blocked FM4-64 internalization in syt1syt3 double mutants by displacing peripheral and core TPC subunits from the PM. Loss of SYT1 reduced brassinosteroid receptor internalization during cold stress, while double mutants showed enhanced brassinosteroid signaling. SYTs and VAP27 genes showed a condition-dependent genetic interaction in endocytosis: the syt1/vap27-1/vap27-3 triple mutant resembles vap27-1/vap27-3 under control conditions and syt1 during cold stress, suggesting overlapping contributions to endocytic regulation. Using molecular dynamics simulations of protein-membrane interactions, phosphoinositide depletion combined with increased diacylglycerol weakened TPC core membrane association. Our findings identify SYT1 and SYT3 as essential components for sustaining endocytosis during abiotic stress and support a model in which lipid homeostasis at endoplasmic reticulum-PM contact sites preserves the membrane composition required for TPC-dependent endocytosis.

plant biology↗

bioRxiv2026

Arabidopsis BAG proteins regulate cellulose synthase stability

Cellulose synthase complexes (CSCs) synthesize cellulose at the plasma membrane, and their activity and trafficking are critical for maintaining cell wall integrity during plant growth. Clathrin-mediated endocytosis (CME) regulates CSC internalization and has been implicated in their rapid stress-induced removal from the plasma membrane. Stress adaptation, instead, requires the maintenance of a subset of CSCs at the plasma membrane, yet the mechanisms underlying this homeostasis remain poorly understood. The Arabidopsis Bcl-2-associated athanogene4 (BAG4) was identified as an interactor of the adaptor protein 2 complex (AP-2) and the TPLATE complex (TPC), two key components of plant CME. Here, we show that AP-2 and the TPC associated with four closely related BAG proteins, BAG1-BAG4. A quadruple mutant exhibited abnormal growth, increased sensitivity to salt stress, and reduced endocytic flux. However, the abundance, localization and dynamics of CME machinery was largely unaffected, suggesting that BAG proteins are not core regulators of CME. Instead, BAG1-BAG4 deficiency caused hypersensitivity to cellulose biosynthesis inhibitors and impaired hypocotyl elongation in darkness, consistent with defective cellulose-dependent growth. BAG1-BAG4 also interacted with CESA6, and salt-induced CESA6 degradation and ubiquitination was enhanced in the quadruple mutant. Together, these findings identify BAG1-BAG4 as redundant proteostasis factors that safeguard CESA6 stability during salt stress, thereby maintaining cellulose synthesis, cell wall integrity, and plant stress tolerance.

plant biology↗

bioRxiv2026

The molecular architecture of the Arabidopsis callose synthase complex

ABSTRACTCallose synthase is responsible for the targeted deposition of the {beta}-1,3-glucan polymer, callose which underlines essential plant developmental processes, including cell division, pathogen defense or cell-cell communication. The architecture of the callose synthase complex (CALSC) as well as the molecular mechanisms of callose synthesis remain unknown. Here we report an integrative characterisation of the Arabidopsis CALS complex, with the most enriched subunits, CALS1, CALS2 and CALS3, forming its core. Structurally, CALSC assembles into a trimer, requiring the plant-specific Bag domain to mediate inter-subunit associations. The biological importance of CALSC assembly is highlighted by the simultaneous loss of CALS1 and CALS3, which abolishes plasmodesmal callose deposition and affects symplastic transport. Site-directed mutagenesis and molecular dynamics simulations depict the topology of the CALS1 active site in detail, including the components of the enzymatic reaction. We pinpoint the translocating tunnel through which the nascent glucan is delivered and mechanistically confirm the role of transmembrane helix 8 in regulating glucan export. Our work provides unprecedented insight into the molecular architecture of the CALSC and the distinct changes from maturation to activity at the plasma membrane, while showcasing the mechanisms involved in callose synthesis at the molecular level.

plant biology↗

bioRxiv2026

A Myb-dominated gene regulatory network universally controls sexual cell fate transitions in diatoms

Diatoms are the foundation of aquatic food webs and contribute about 40% of the total marine primary productivity. Yet, the regulation of their complex size-dependent life cycles remains obscure. Here, we leveraged single-cell transcriptomics and transgenic reporter lines to uncover the molecular mechanisms behind partner recognition, nuclear fusion, and the remarkable 15-fold size expansion of auxospores. Gene regulatory network inference revealed that the irreversible commitment to differentiate into gametes is controlled by Myb transcription factors, whose specific activity in the global ocean underscores their significance for ploidy transitions across diatom clades. These findings reinforce microalgae as powerful models to study cell fate transitions and provide a mechanistic framework for the life cycle dynamics that underpin the functioning of aquatic systems worldwide. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=67 SRC="FIGDIR/small/714157v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@162f523org.highwire.dtl.DTLVardef@1cbe836org.highwire.dtl.DTLVardef@1fa6c9eorg.highwire.dtl.DTLVardef@1f12217_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

Clathrin-coated vesicles are targeted for selective autophagy during osmotic stress.

Plants frequently encounter hyperosmotic stress due to drought and salinity, leading to rapid water loss, reduced turgor pressure, and decreased cell volume. This contraction drastically alters plasma membrane tension, a physical parameter that must be strictly maintained to support mechanosignaling and cell expansion. However, the mechanisms by which plants adjust their membrane surface area to match a shrinking cell volume remain poorly understood. Here, we identify selective autophagy dependent degradation of plasma membrane-derived clathrin-coated vesicles (CCVs) in response to hyperosmotic shock. This pathway involves the recruitment of the endocytic TPLATE complex (TPC) to autophagosomes in an osmotic-stress dependent manner. Through correlative light and electron microscopy (CLEM) and electron tomography (ET), we provide ultrastructural evidence of the physical association of CCVs with autophagosome membranes. These autophagosomes contain endocytic machinery, including TPC and clathrin, and are targeted to the vacuole. Mechanistically, we show that the conserved ATG8-interacting motifs (AIMs) in the AtEH1/Pan1 and AtEH2/Pan1 TPC subunits interact with ATG8, suggesting that they facilitate the recruitment of CCVs to autophagosomes. Using time-lapse imaging, we demonstrate that the acute induction of autophagy is precisely coupled to the reduction in cell volume under hyperosmolar conditions. Our results suggest that endocytic removal of excess plasma membrane to maintain membrane tension and cellular integrity is coupled to TPC-mediated CCV-phagy. These findings reveal a homeostatic mechanism that enables plants to adapt to the challenges of drought and salinity. Significance StatementAll living cells must maintain the physical integrity of their outer membrane. How cells can adapt their surface area to respond to rapid changes in cell volume, such as those caused by drought or salt stress, remains a fundamental question in biology. We identify a mechanism in plants involving autophagy - a cellular recycling pathway - where plasma membrane-derived vesicles are targeted for degradation following salt or osmotic stress. This pathway involves the TPLATE complex, an evolutionary ancient and essential endocytic complex in plants, which directly interacts with the autophagy protein ATG8. This discovery reveals how plants adapt to osmotic stress by modulating their membrane properties, supporting a framework for future improvement of crop resilience in response to salinity and drought.

plant biology↗

bioRxiv2025

Secretory carrier membrane proteins assist with aquaporin trafficking in Arabidopsis.

Aquaporins belonging to the plasma membrane intrinsic protein (PIP) subfamily are channel proteins that control water flow across cells, allowing plants to rapidly adjust hydraulic conductivity and thereby sustain growth, gas exchange, and recovery from drought. We show that secretory carrier membrane proteins (SCAMP) regulate the abundance of the aquaporins and thereby water transport in Arabidopsis root cells. SCAMPs are evolutionarily conserved multi-spanning transmembrane proteins. In animal cells, they function in secretion, endocytosis and autophagy. Knowledge on their role in plants is restricted to localization and trafficking experiments in heterologous systems and few genetic perturbation experiments. Here, we analysed all five members of the Arabidopsis SCAMP family. We identified conserved tyrosine motifs assisting in transport to the plasma membrane and N-terminally located NPF motifs that are required for internalization. SCAMPs dimerize both at the plasma membrane and endosomes, and dimerization is required for their internalization. Functionally, several PIPs were identified as common targets of multiple SCAMP isoforms. Triple and quintuple scamp mutants show mild developmental delay under standard growth conditions, but they are less sensitive to drought-induced leaf wilting. This observation cannot be explained by altered stomatal dynamics or densities, nor by differential soil water content. However, scamp mutant root protoplasts contain less PIPs and swell less under hypotonic conditions compared to wild type, indicating reduced PIP plasma membrane levels. In conclusion, our research identifies the SCAMP membrane trafficking proteins as regulators of PIP abundance at the plasma membrane in root cells. We propose that the reduced PIP levels in the scamp mutants act as a priming mechanism, allowing them to respond better to conditions of reduced water availability.

plant biology↗

bioRxiv2024

The structural scaffold of the TPLATE complex deforms the membrane during plant endocytosis

Summary paragraphEukaryotic cells maintain homeostasis of their outer membrane by controlled internalization of lipid and protein constituents via endocytosis1. Endocytosis is evolutionary conserved and utilizes similar structural folds. How these structural folds are combined into proteins and protein complexes however differs between eukaryotic kingdoms2. The TPLATE complex in plants is an evolutionary ancient protein module that combines several endocytic folds into a single octameric protein complex3-5. Its molecular architecture, lipid-nucleated condensate formation, and its requirement for clathrin cage curvature revealed its function in endocytosis initiation in plants6-8. Mechanistic understanding of how this complex drives membrane deformation during plant endocytosis is, however, lacking. Here, we used an integrative structural approach to obtain a precise molecular structure of the TPLATE complex. In addition, our approach allowed visualizing the structural flexibility that hallmarks this enigmatic complex. We prove that the intrinsic structural flexibility is required for its functionality and membrane recruitment. The membrane binding interface consists of several domains with differential lipid preferences. Finally, we show that the crescent shape of the structured part of the complex is sufficient for membrane curvature generation. Our mechanistic insight answers the long-standing question of how plants execute endocytosis without cytoskeletal-based force generation.

plant biology↗

bioRxiv2024

Burning glass effect of water droplets triggers an ER-derived calcium response in the chloroplast stroma of Arabidopsis thaliana leaves

Plants require water and light for photosynthesis, but light, when focused by water droplets on leaves, can create high light intensity spots that are harmful to plants. As excessive light intensity can reduce growth or even induce cell death, it is vital for plants to detect and react to changes in light exposure and acclimate to high light stress. Ca2+ signaling was previously implicated in high light acclimation. However, the dynamics of free Ca2+ concentration in the chloroplast, the primary site of photosynthesis, or in the nucleus and in the cytoplasm, where transcription and translation for long-term acclimation occurs, remain unknown. Here we studied the dynamics and mechanism of the Ca2+ response to high light exposure. Focusing light through a glass bead to mimic water droplets triggered an increase of the free Ca2+ concentration in the chloroplast stroma of Arabidopsis thaliana. This finding was corroborated using established and newly developed genetically encoded calcium indicators, which revealed a biphasic increase in the stromal free Ca2+ concentration when exposed to varying intensities and qualities of light. Among photosynthetic by-products, reactive oxygen and lipophilic species in particular, have been implicated in high light stress acclimation. A H2O2 signature was induced, albeit with different dynamics than the Ca2+ response, while chemical inhibition of the photosynthetic electron transport points towards singlet oxygen as a potential culprit of the high light-induced increase in stromal free Ca2+ concentration. The observed dynamics differed from those of a heat-shock induced Ca2+ signature, although temperature had a positive effect on the Ca2+ response. Based on Ca2+ inhibitor treatments and the free Ca2+ concentration dynamics, we suggest that the high light-induced stromal Ca2+ is derived from the endoplasmic reticulum rather than from the cytoplasm. In conclusion, inspired by the burning glass effect of water droplets on leaves, we uncovered a Ca2+ response that implicates a novel mechanism for plants to acclimate to high light stress--a process that will become increasingly relevant in a changing climate.

plant biology↗

bioRxiv2023

A precise balance of TETRASPANIN1/TORNADO2 activity is required for vascular proliferation and ground tissue patterning in Arabidopsis

The molecular mechanisms guiding oriented cell divisions in the root vascular tissues of Arabidopsis thaliana are still poorly characterized. By overlapping bulk and single-cell transcriptomic datasets, we unveiled TETRASPANIN1 (TET1) as a putative regulator in this process. TET1 is expressed in root vascular cells and loss-of-function mutants contain fewer vascular cells files. We further generated and characterized a CRISPR deletion mutant and show, unlike previously described mutants, that the full knock out is additionally missing endodermal cells in a stochastic way. Finally, we show that HA-tagged versions of TET1 are functional in contrast to fluorescent TET1 translational fusions. Immunostaining using HA-TET1 lines complementing the mutant phenotype revealed a dual plasma membrane and intracellular localization in the root vasculature and a polar membrane localization in young cortex, endodermal and initial cells. Taken together, we show that TET1 is involved in both vascular proliferation and ground tissue patterning. Our initial results pave the way for future work into deciphering its precise mode of action. Summary statementThis study reveals a novel role of tetraspanin TET1/TRN2 in root vascular development and ground tissue patterning in the model plant Arabidopsis thaliana.

plant biology↗

bioRxiv2023

SMB controls decompartmentalization in Arabidopsis root cap cells to execute programmed cell death

Programmed cell death (PCD) is a fundamental cellular process crucial to development, homeostasis, and immunity in multicellular eukaryotes. In contrast to our knowledge on the regulation of diverse animal cell death subroutines, information on execution of PCD in plants remains fragmentary. Here we make use of the accessibility of the Arabidopsis thaliana root cap to visualize the execution process of developmentally controlled PCD. We identify a succession of selective decompartmentalization events and ion fluxes that are controlled by a gene regulatory network downstream of the NAC transcription factor SOMBRERO (SMB). Surprisingly, breakdown of the large central vacuole is a relatively late and variable event, preceded by an increase of intracellular calcium levels and acidification, release of mitochondrial matrix proteins, leakage of nuclear and endoplasmic reticulum lumina, and release of fluorescent membrane reporters into the cytosol. Elevated intracellular calcium levels and acidification are sufficient to trigger cell death execution specifically in cells that are rendered competent to undergo PCD by SMB activity, suggesting that these ion fluxes act as PCD-triggering signals.

plant biology↗

bioRxiv2023

Chromatin attachment to the nuclear matrix represses hypocotyl elongation in Arabidopsis thaliana

The nuclear matrix is a nuclear compartment that has diverse functions in chromatin regulation and transcription. However, how this structure influences epigenetic modifications and gene expression in plants is largely unknown. In this study, we showed that a nuclear matrix binding protein, AHL22, together with the two transcriptional repressors FRS7 and FRS12, regulates hypocotyl elongation by suppressing the expression of a group of genes known as SMALL AUXIN UP RNAs (SAURs) in Arabidopsis thaliana. The transcriptional repression of SAURs depends on their attachment to the nuclear matrix. The AHL22 complex not only brings these SAURs, which contained matrix attachment regions (MARs), to the nuclear matrix, but it also recruits the histone deacetylase HDA15 to the SAUR loci. This leads to the removal of H3 acetylation at the SAUR loci and the suppression of hypocotyl elongation. Taken together, our results indicate that MAR-binding proteins act as a hub for chromatin and epigenetic regulators. Moreover, we present a novel mechanism by which nuclear matrix attachment to chromatin regulates histone modifications, transcription, and hypocotyl elongation.

plant biology↗

bioRxiv2022

TPLATE complex dependent endocytosis is required for shoot apical meristem maintenance by 1 attenuating CLAVATA1 signaling

Endocytosis regulates the turnover of cell surface localized receptors, which are crucial for plants to sense and rapidly respond to both endogenous and environmental stimuli. The evolutionarily ancient TPLATE complex (TPC) plays an essential role in clathrin-mediated endocytosis (CME) in Arabidopsis plants. Knockout or strong knockdown of single TPC subunits causes male sterility and seedling lethality phenotypes, complicating analysis of the roles of TPC during plant development. Partially functional alleles of TPC subunits however only cause very mild developmental deviations. Here, we took advantage of the recently reported partially functional TPLATE allele, WDXM2, to investigate a role for TPC-dependent endocytosis in receptor-mediated signalling. We discovered that reduced TPC-dependent endocytosis confers a hypersensitivity to very low doses of CLAVATA3 (CLV3) peptide signalling. This hypersensitivity correlated with the abundance of the CLV3 receptor protein kinase CLAVATA1 (CLV1) at the plasma membrane. Genetic analysis and live-cell imaging revealed that TPC-dependent regulation of CLV3-dependent internalization of CLV1 from the plasma membrane is required for CLV3 function in the shoot. Our findings provide evidence that clathrin-mediated endocytosis of CLV1 is a mechanism to dampen CLV3-mediated signaling during plant development.

plant biology↗

bioRxiv2022

Phase separation-based visualization of protein-protein interactions and kinase activities in plants

Protein activities depend heavily on protein complex formation and dynamic post-translational modifications, such as phosphorylation. Their dynamic nature is notoriously difficult to monitor in planta at cellular resolution, often requiring extensive optimization and high-end microscopy. Here, we generated and exploited the SYnthetic Multivalency in PLants (SYMPL)-vector set to study protein-protein interactions (PPIs) and kinase activities in planta based on phase separation. This technology enabled easy detection of inducible, binary and ternary protein-protein interactions among cytoplasmic, nuclear and plasma membrane proteins in plant cells via a robust image-based readout. Moreover, we applied the SYMPL toolbox to develop an in vivo reporter for SnRK1 kinase activity, allowing us to visualize tissue-specific, dynamic SnRK1 activation upon energy deprivation in stable transgenic Arabidopsis plants. The applications of the SYMPL cloning toolbox lay the foundation for the exploration of PPIs, phosphorylation and other post-translational modifications with unprecedented ease and sensitivity.

plant biology↗

bioRxiv2022

Mapping the adaptor protein complex interaction network in Arabidopsis identifies P34 as a common stability regulator

Adaptor protein (AP) complexes are evolutionarily conserved vesicle transport regulators that recruit coat proteins, membrane cargos and coated vesicle accessory proteins. Since in plants endocytic and post-Golgi trafficking intersect at the trans-Golgi network, unique mechanisms for sorting cargos of overlapping vesicular routes are anticipated. The plant AP complexes are part of the sorting machinery, but despite some functional information, their cargoes, accessory proteins, and regulation remain largely unknown. Here, by means of various proteomics approaches, we generated the overall interactome of the five AP and the TPLATE complexes in Arabidopsis thaliana. The interactome converged on a number of hub proteins, including the thus far unknown adaptin binding-like protein, designated P34. P34 interacted with the clathrin-associated AP complexes, controlled their stability and, subsequently, influenced clathrin-mediated endocytosis and various post-Golgi trafficking routes. Altogether, the AP interactome network offers substantial resources for further discoveries of unknown endomembrane trafficking regulators in plant cells.

plant biology↗

bioRxiv2022

Phosphorylation and ubiquitination independent endocytosis of BRI1

The brassinosteroid (BR) hormone and its plasma membrane receptor BR INSENSITIVE1 (BRI1) is one of the best-studied receptor-ligand pairs for understanding the interplay between receptor endocytosis and signaling in plants. BR signaling is mainly determined by the plasma membrane pool of BRI1, whereas BRI1 endocytosis ensures signal attenuation. Since BRs are ubiquitously distributed in the plant, the tools available to study BRI1 function without interference from endogenous BRs are limited. Here, we designed a BR-binding-deficient mutant based on protein sequence-structure analysis and homology modeling of BRI1 and its close homologues. This new tool allowed us to re-examine the BRI1 endocytosis and signal attenuation model. We show that despite decreased phosphorylation and ubiquitination, the BR-binding-deficient BRI1 was internalized similar to the wild type form. These results reinforce the hypothesis that BRI1 is internalized via parallel endocytic routes and machineries. In addition, BR-binding-deficient mutant provides opportunities to study non-canonical ligand-independent BRI1 functions.

plant biology↗

bioRxiv2022

AtEH/Pan1 proteins drive phase separation of the TPLATE complex and clathrin polymerisation during plant endocytosis

Clathrin-mediated endocytosis (CME) is an essential cellular internalisation pathway involving the dynamic assembly of clathrin and accessory proteins to form membrane-bound vesicles. In plants, the evolutionarily ancient TSET/TPLATE complex (TPC) plays an essential, but not well-defined role in CME. Here, we show that two highly disordered TPC subunits, AtEH1 and AtEH2 function as scaffolds to drive biomolecular condensation of the complex. These condensates specifically nucleate on the plasma membrane through interactions with anionic phospholipids, and facilitate the dynamic recruitment and assembly of clathrin, early-, and late-stage endocytic accessory proteins. Importantly, clathrin forms ordered assemblies within the condensate environment. Biomolecular condensation therefore acts to promote dynamic protein assemblies throughout clathrin-mediated endocytosis. Furthermore, the disordered region sequence properties of AtEH1 regulate the material properties of the endocytic condensates in vivo and alteration of these material properties influences endocytosis dynamics, and consequently plant adaptive growth. HighlightsO_LIAtEH subunits are endocytic scaffolds which drive condensation of the TPC C_LIO_LIAtEH1 condensates nucleate on the plasma membrane via lipid interactions C_LIO_LICondensation of AtEH1/TPC facilitates clathrin re-arrangement and assembly C_LIO_LIAtEH1 IDR1 composition controls condensate properties to regulate endocytosis C_LI

cell biology↗

bioRxiv2022

MYB12 spatiotemporally represses TMO5/LHW-mediated transcription in the Arabidopsis root meristem

Transcriptional networks are crucial to integrate various internal and external signals into optimal responses during plant growth and development. Primary root vasculature patterning and proliferation are controlled by a network centred around the basic Helix-Loop-Helix transcription factor complex formed by TARGET OF MONOPTEROS 5 (TMO5) and LONESOME HIGHWAY (LHW), which control cell proliferation and orientation by modulating cytokinin response and other downstream factors. Despite recent progress, many aspects of the TMO5/LHW pathway are not fully understood. In particular, the upstream regulators of TMO5/LHW activity remain unknown. Here, using a forward genetic approach to identify new factors of the TMO5/LHW pathway, we discovered a novel function of the MYB-type transcription factor MYB12. MYB12 physically interacts with TMO5 and dampens the TMO5/LHW-mediated induction of direct target gene expression as well as the periclinal/radial cell divisions. The expression of MYB12 is activated by the cytokinin response, downstream of TMO5/LHW, resulting in a novel MYB12-mediated negative feedback loop that restricts TMO5/LHW activity to ensure optimal cell proliferation rates during root vascular development.

plant biology↗

bioRxiv2021

Proteomic Characterization of Isolated Arabidopsis Clathrin-Coated Vesicles Reveals Evolutionarily Conserved and Plant Specific Components

In eukaryotes, clathrin-coated vesicles (CCVs) facilitate the internalization of material from the cell surface as well as the movement of cargo in post-Golgi trafficking pathways. This diversity of functions is partially provided by multiple monomeric and multimeric clathrin adaptor complexes that provide compartment and cargo selectivity. The adaptor- protein AP-1 complex operates as part of the secretory pathway at the trans-Golgi network, while the AP-2 complex and the TPLATE complex (TPC) jointly operate at the plasma membrane to execute clathrin-mediated endocytosis. Key to our further understanding of clathrin-mediated trafficking in plants will be the comprehensive identification and characterization of the network of evolutionarily conserved and plant- specific core and accessory machinery involved in the formation and targeting of CCVs. To facilitate these studies, we have analyzed the proteome of enriched trans-Golgi network/early endosome-derived and endocytic CCVs isolated from dividing and expanding suspension-cultured Arabidopsis cells. Tandem mass spectrometry analysis results were validated by differential chemical labeling experiments to identify proteins co-enriching with CCVs. Proteins enriched in CCVs included previously characterized CCV components and cargos such as the vacuolar sorting receptors in addition to conserved and plant-specific components whose function in clathrin-mediated trafficking has not been previously defined. Notably, in addition to AP-1 and AP-2, all subunits of the AP-4 complex, but not AP-3 or AP-5, were found to be in high abundance in the CCV proteome. The association of AP-4 with suspension-cultured Arabidopsis CCVs is further supported via additional biochemical data.

cell biology↗