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Tarafdar S, Chowdhary G. Translating the Arabidopsis thaliana Peroxisome Proteome Insights to Solanum lycopersicum: Consensus Versus Diversity. Front Cell Dev Biol 2022; 10:909604. [PMID: 35912119 PMCID: PMC9328179 DOI: 10.3389/fcell.2022.909604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/06/2022] [Indexed: 11/25/2022] Open
Abstract
Peroxisomes are small, single-membrane specialized organelles present in all eukaryotic organisms. The peroxisome is one of the nodal centers of reactive oxygen species homeostasis in plants, which are generated in a high amount due to various stress conditions. Over the past decade, there has been extensive study on peroxisomal proteins and their signaling pathways in the model plant Arabidopsis thaliana, and a lot has been deciphered. However, not much impetus has been given to studying the peroxisome proteome of economically important crops. Owing to the significance of peroxisomes in the physiology of plants during normal and stress conditions, understating its proteome is of much importance. Hence, in this paper, we have made a snapshot of putative peroxisomal matrix proteins in the economically important vegetable crop tomato (Solanum lycopersicum, (L.) family Solanaceae). First, a reference peroxisomal matrix proteome map was generated for Arabidopsis thaliana using the available proteomic and localization studies, and proteins were categorized into various groups as per their annotations. This was used to create the putative peroxisomal matrix proteome map for S. lycopersicum. The putative peroxisome proteome in S. lycopersicum retains the basic framework: the bulk of proteins had peroxisomal targeting signal (PTS) type 1, a minor group had PTS2, and the catalase family retained its characteristic internal PTS. Apart from these, a considerable number of S. lycopersicum orthologs did not contain any “obvious” PTS. The number of PTS2 isoforms was found to be reduced in S. lycopersicum. We further investigated the PTS1s in the case of both the plant species and generated a pattern for canonical and non-canonical PTS1s. The number of canonical PTS1 proteins was comparatively lesser in S. lycopersicum. The non-canonical PTS1s were found to be comparable in both the plant species; however, S. lycopersicum showed greater diversity in the composition of the signal tripeptide. Finally, we have tried to address the lacunas and probable strategies to fill those gaps.
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Kunze M. The type-2 peroxisomal targeting signal. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118609. [PMID: 31751594 DOI: 10.1016/j.bbamcr.2019.118609] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
The type-2 peroxisomal targeting signal (PTS2) is one of two peptide motifs destining soluble proteins for peroxisomes. This signal acts as amphiphilic α-helix exposing the side chains of all conserved residues to the same side. PTS2 motifs are recognized by a bipartite protein complex consisting of the receptor PEX7 and a co-receptor. Cargo-loaded receptor complexes are translocated across the peroxisomal membrane by a transient pore and inside peroxisomes, cargo proteins are released and processed in many, but not all species. The components of the bipartite receptor are re-exported into the cytosol by a ubiquitin-mediated and ATP-driven export mechanism. Structurally, PTS2 motifs resemble other N-terminal targeting signals, whereas the functional relation to the second peroxisomal targeting signal (PTS1) is unclear. Although only a few PTS2-carrying proteins are known in humans, subjects lacking a functional import mechanism for these proteins suffer from the severe inherited disease rhizomelic chondrodysplasia punctata.
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Affiliation(s)
- Markus Kunze
- Medical University of Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, Spitalgasse 4, 1090 Vienna, Austria.
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Corpas FJ, Barroso JB. Peroxisomal plant metabolism - an update on nitric oxide, Ca 2+ and the NADPH recycling network. J Cell Sci 2018; 131:jcs.202978. [PMID: 28775155 DOI: 10.1242/jcs.202978] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plant peroxisomes are recognized organelles that - with their capacity to generate greater amounts of H2O2 than other subcellular compartments - have a remarkable oxidative metabolism. However, over the last 15 years, new information has shown that plant peroxisomes contain other important molecules and enzymes, including nitric oxide (NO), peroxynitrite, a NADPH-recycling system, Ca2+ and lipid-derived signals, such as jasmonic acid (JA) and nitro-fatty acid (NO2-FA). This highlights the potential for complex interactions within the peroxisomal nitro-oxidative metabolism, which also affects the status of the cell and consequently its physiological processes. In this review, we provide an update on the peroxisomal interactions between all these molecules. Particular emphasis will be placed on the generation of the free-radical NO, which requires the presence of Ca2+, calmodulin and NADPH redox power. Peroxisomes possess several NADPH regeneration mechanisms, such as those mediated by glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) proteins, which are involved in the oxidative phase of the pentose phosphate pathway, as well as that mediated by NADP-isocitrate dehydrogenase (ICDH). The generated NADPH is also an essential cofactor across other peroxisomal pathways, including the antioxidant ascorbate-glutathione cycle and unsaturated fatty acid β-oxidation, the latter being a source of powerful signaling molecules such as JA and NO2-FA.
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Affiliation(s)
- Francisco J Corpas
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/Profesor Albareda 1, E-18008 Granada, Spain
| | - Juan B Barroso
- Group of Biochemistry and Cell Signaling in Nitric Oxide, Department of Experimental Biology, Center for Advanced Studies in Olive Grove and Olive Oils, Faculty of Experimental Sciences, Campus Universitario "Las Lagunillas" s/n, University of Jaén, E-23071, Jaén, Spain
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Abstract
Despite of their economical and nutritional interest, the biology of fruits is still little studied in comparison with reports of other plant organs such as leaves and roots. Accordingly, research at subcellular and molecular levels is necessary not only to understand the physiology of fruits, but also to improve crop qualities. Efforts addressed to gain knowledge of the peroxisome proteome and how it interacts with the overall metabolism of fruits will provide tools to be used in breeding strategies of agricultural species with added value. In this work, special attention will be paid to peroxisomal proteins involved in the metabolism of reactive oxygen species (ROS) due to the relevant role of these compounds at fruit ripening. The proteome of peroxisomes purified from sweet pepper (Capsicum annuum L.) fruit is reported, where an iron-superoxide dismutase (Fe-SOD) was localized in these organelles, besides other antioxidant enzymes such as catalase and a Mn-SOD, as well as enzymes involved in the metabolism of carbohydrates, malate, lipids and fatty acids, amino acids, the glyoxylate cycle and in the potential organelles' movements.
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Bhogal MS, Lanyon-Hogg T, Johnston KA, Warriner SL, Baker A. Covalent Label Transfer between Peroxisomal Importomer Components Reveals Export-driven Import Interactions. J Biol Chem 2015; 291:2460-8. [PMID: 26567336 PMCID: PMC4732227 DOI: 10.1074/jbc.m115.686501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Indexed: 11/06/2022] Open
Abstract
Peroxisomes are vital metabolic organelles found in almost all eukaryotic organisms, and they rely exclusively on import of their matrix protein content from the cytosol. In vitro import of proteins into isolated peroxisomal fractions has provided a wealth of knowledge on the import process. However, the common method of protease protection garnered no information on the import of an N-terminally truncated PEX5 (PEX5C) receptor construct or peroxisomal malate dehydrogenase 1 (pMDH1) cargo protein into sunflower peroxisomes because of high degrees of protease susceptibility or resistance, respectively. Here we present a means for analysis of in vitro import through a covalent biotin label transfer and employ this method to the import of PEX5C. Label transfer demonstrates that the PEX5C construct is monomeric under the conditions of the import assay. This technique was capable of identifying the PEX5-PEX14 interaction as the first interaction of the import process through competition experiments. Labeling of the peroxisomal protein import machinery by PEX5C demonstrated that this interaction was independent of added cargo protein, and, strikingly, the interaction between PEX5C and the import machinery was shown to be ATP-dependent. These important mechanistic insights highlight the power of label transfer in studying interactions, rather than proteins, of interest and demonstrate that this technique should be applied to future studies of peroxisomal in vitro import.
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Affiliation(s)
- Moninder S Bhogal
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and
| | - Thomas Lanyon-Hogg
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and School of Chemistry and Astbury Centre, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Katherine A Johnston
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and
| | - Stuart L Warriner
- School of Chemistry and Astbury Centre, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Alison Baker
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and
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PiSCP1 and PiCDPK2 Localize to Peroxisomes and Are Involved in Pollen Tube Growth in Petunia Inflata. PLANTS 2013; 2:72-86. [PMID: 27137367 PMCID: PMC4844289 DOI: 10.3390/plants2010072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 02/19/2013] [Accepted: 02/26/2013] [Indexed: 01/13/2023]
Abstract
Petunia inflata small CDPK-interacting protein 1 (PiSCP1) was identified as a pollen expressed PiCDPK1 interacting protein using the yeast two hybrid system and the interaction confirmed using pull-down and phosphorylation assays. PiSCP1 is pollen specific and shares amino acid homology with uncharacterized proteins from diverse species of higher plants, but no protein of known function. Expression of PiSCP1-GFP in vivo inhibited pollen tube growth and was shown to localize to peroxisomes in growing pollen tubes. As PiCDPK1 is plasma membrane localized, we investigated the localization of a second isoform, PiCDPK2, and show that it co-localizes to peroxisomes with PiSCP1 and that the two proteins interact in the yeast 2 hybrid interaction assay, suggesting that interaction with the latter CDPK isoform is likely the one of biological relevance. Both PiCDPK2 and PiSCP1 affect pollen tube growth, presumably by mediating peroxisome function, however how they do so is currently not clear.
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Wiesemann K, Groß LE, Sommer M, Schleiff E, Sommer MS. self-assembling GFP: a versatile tool for plant (membrane) protein analyses. Methods Mol Biol 2013; 1033:131-144. [PMID: 23996175 DOI: 10.1007/978-1-62703-487-6_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The investigation of cellular processes on the molecular level is important to understand the functional network within plant cells. self-assembling GFP has evolved to be a versatile tool for (membrane) protein analyses. Based on the autocatalytical reassembling property of the nonfluorescent strands 1-10 and 11, protein distribution and membrane protein topology can be analyzed in vivo. Here, we provide basic protocols to determine membrane protein topology in Arabidopsis thaliana protoplasts.
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Affiliation(s)
- Katharina Wiesemann
- Cluster of Excellence Frankfurt, Center for Membrane Proteomics, Department of Biosciences, Molecular Cell Biology, Goethe University, Frankfurt, Germany
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Matre P, Meyer C, Lillo C. Diversity in subcellular targeting of the PP2A B'eta subfamily members. PLANTA 2009; 230:935-45. [PMID: 19672620 DOI: 10.1007/s00425-009-0998-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Accepted: 07/22/2009] [Indexed: 05/20/2023]
Abstract
Protein phosphatase 2A (PP2A) is a serine/threonine-specific phosphatase comprising a catalytic subunit (C), a scaffolding subunit (A), and a regulatory subunit (B). The B subunits are believed to be responsible for substrate specificity and localization of the PP2A complex. In plants, three families of B subunits exist, i.e. B (B55), B', and B''. Here, we report differential subcellular targeting within the Arabidopsis B'eta subfamily, which consists of the close homologs B'eta, B'theta, B'gamma and B'zeta. Phenotypes of corresponding knockouts were observed, and particularly revealed delayed flowering for the B'eta knockout. The B' subunits were linked to fluorescent tags and transiently expressed in various tissues of onion, tobacco and Arabidopsis. B'eta and B'gamma targeted the cytosol and nucleus. B'zeta localized to the cytoplasm and partly co-localized with mitochondrial markers when the N-terminus was free. Provided its C-terminus was free, the B'theta subunit targeted peroxisomes. The importance of the C-terminal end for peroxisomal targeting was further confirmed by truncation of the C-terminus. The results revealed that the closely related B' subunits are targeting different organelles in plants, and exemplify the usage of the peptide serine-serine-leucine as a PTS1 peroxisomal signaling peptide.
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Affiliation(s)
- Polina Matre
- Faculty of Science and Technology, University of Stavanger, Centre for Organelle Research, 4036 Stavanger, Norway
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Van Moerkercke A, Schauvinhold I, Pichersky E, Haring MA, Schuurink RC. A plant thiolase involved in benzoic acid biosynthesis and volatile benzenoid production. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 60:292-302. [PMID: 19659733 DOI: 10.1111/j.1365-313x.2009.03953.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The exact biosynthetic pathways leading to benzoic acid (BA) formation in plants are not known, but labeling experiments indicate the contribution of both beta-oxidative and non-beta-oxidative pathways. In Petunia hybrida BA is a key precursor for the production of volatile benzenoids by its flowers. Using functional genomics, we identified a 3-ketoacyl-CoA thiolase, PhKAT1, which is involved in the benzenoid biosynthetic pathway and the production of BA. PhKAT1 is localised in the peroxisomes, where it is important for the formation of benzoyl-CoA-related compounds. Silencing of PhKAT1 resulted in a major reduction in BA and benzenoid formation, leaving the production of other phenylpropanoid-related volatiles unaffected. During the night, when volatile benzenoid production is highest, it is largely the beta-oxidative pathway that contributes to the formation of BA and benzenoids. Our studies add the benzenoid biosynthetic pathway to the list of pathways in which 3-ketoacyl-CoA thiolases are involved in plants.
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Affiliation(s)
- Alex Van Moerkercke
- Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
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Pex2 and pex12 function as protein-ubiquitin ligases in peroxisomal protein import. Mol Cell Biol 2009; 29:5505-16. [PMID: 19687296 DOI: 10.1128/mcb.00388-09] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The PTS1-dependent peroxisomal matrix protein import is facilitated by the receptor protein Pex5 and can be divided into cargo recognition in the cytosol, membrane docking of the cargo-receptor complex, cargo release, and recycling of the receptor. The final step is controlled by the ubiquitination status of Pex5. While polyubiquitinated Pex5 is degraded by the proteasome, monoubiquitinated Pex5 is destined for a new round of the receptor cycle. Recently, the ubiquitin-conjugating enzymes involved in Pex5 ubiquitination were identified as Ubc4 and Pex4 (Ubc10), whereas the identity of the corresponding protein-ubiquitin ligases remained unknown. Here we report on the identification of the protein-ubiquitin ligases that are responsible for the ubiquitination of the peroxisomal protein import receptor Pex5. It is demonstrated that each of the three RING peroxins Pex2, Pex10, and Pex12 exhibits ubiquitin-protein isopeptide ligase activity. Our results show that Pex2 mediates the Ubc4-dependent polyubiquitination whereas Pex12 facilitates the Pex4-dependent monoubiquitination of Pex5.
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Carrie C, Murcha MW, Millar AH, Smith SM, Whelan J. Nine 3-ketoacyl-CoA thiolases (KATs) and acetoacetyl-CoA thiolases (ACATs) encoded by five genes in Arabidopsis thaliana are targeted either to peroxisomes or cytosol but not to mitochondria. PLANT MOLECULAR BIOLOGY 2007; 63:97-108. [PMID: 17120136 DOI: 10.1007/s11103-006-9075-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2006] [Accepted: 08/10/2006] [Indexed: 05/12/2023]
Abstract
The sub-cellular location of enzymes of fatty acid beta-oxidation in plants is controversial. In the current debate the role and location of particular thiolases in fatty acid degradation, fatty acid synthesis and isoleucine degradation are important. The aim of this research was to determine the sub-cellular location and hence provide information about possible functions of all the putative 3-ketoacyl-CoA thiolases (KAT) and acetoacetyl-CoA thiolases (ACAT) in Arabidopsis. Arabidopsis has three genes predicted to encode KATs, one of which encodes two polypeptides that differ at the N-terminal end. Expression in Arabidopsis cells of cDNAs encoding each of these KATs fused to green fluorescent protein (GFP) at their C-termini showed that three are targeted to peroxisomes while the fourth is apparently cytosolic. The four KATs are also predicted to have mitochondrial targeting sequences, but purified mitochondria were unable to import any of the proteins in vitro. Arabidopsis also has two genes encoding a total of five different putative ACATs. One isoform is targeted to peroxisomes as a fusion with GFP, while the others display no targeting in vivo as GFP fusions, or import into isolated mitochondria. Analysis of gene co-expression clusters in Arabidopsis suggests a role for peroxisomal KAT2 in beta-oxidation, while KAT5 co-expresses with genes of the flavonoid biosynthesis pathway and cytosolic ACAT2 clearly co-expresses with genes of the cytosolic mevalonate biosynthesis pathway. We conclude that KATs and ACATs are present in the cytosol and peroxisome, but are not found in mitochondria. The implications for fatty acid beta-oxidation and for isoleucine degradation in mitochondria are discussed.
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Affiliation(s)
- Chris Carrie
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, MCS building M316, 35 Stirling Highway, Crawley, 6009, WA, Australia
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Lazarow PB. Chapter 3.1.7. The import receptor Pex7p and the PTS2 targeting sequence. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1599-604. [PMID: 16996627 DOI: 10.1016/j.bbamcr.2006.08.011] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 07/25/2006] [Accepted: 08/18/2006] [Indexed: 10/24/2022]
Abstract
This chapter concerns one branch of the peroxisome import pathway for newly-synthesized peroxisomal proteins, specifically the branch for matrix proteins that contain a peroxisome targeting sequence type 2 (PTS2). The structure and utilization of the PTS2 are discussed, as well as the properties of the receptor, Pex7p, which recognizes the PTS2 sequence and conveys these proteins to the common translocation machinery in the peroxisome membrane. We also describe the recent evidence that this receptor recycles into the peroxisome matrix and back out to the cytosol in the course of its function. Pex7p is assisted in its functioning by several species-specific auxiliary proteins that are described in the following chapter.
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Harrison-Lowe N, Olsen LJ. Isolation of glyoxysomes from pumpkin cotyledons. CURRENT PROTOCOLS IN CELL BIOLOGY 2006; Chapter 3:Unit 3.19. [PMID: 18228487 DOI: 10.1002/0471143030.cb0319s29] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Peroxisomes are single-membrane-bound organelles found in virtually all eukaryotes. In plants, there are several classes of peroxisomes. Glyoxysomes are found in germinating seedlings and contain enzymes specific for the glyoxylate cycle, including isocitrate lyase and malate synthase. After seedlings become photosynthetic, leaf peroxisomes participate in reactions of the photorespiration pathway and contain characteristic enzymes such as glycolate oxidase and hydroxypyruvate reductase. As leaves begin to senesce, leaf peroxisomes are transformed back into glyoxysomes. Root peroxisomes in the nodules of legumes, for example, sequester enzymes such as allantoinase and uricase, which contribute to nitrogen metabolism in these tissues. Thus, peroxisomes participate in many metabolic pathways and contain specific enzyme complements, depending on the tissue source. All peroxisomes contain catalase to degrade hydrogen peroxide and enzymes to accomplish beta-oxidation of fatty acids. Glyoxysomes can be isolated from pumpkin cotyledons by standard differential centrifugation and density separation, as described in this article.
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Woodward AW, Bartel B. The Arabidopsis peroxisomal targeting signal type 2 receptor PEX7 is necessary for peroxisome function and dependent on PEX5. Mol Biol Cell 2004; 16:573-83. [PMID: 15548601 PMCID: PMC545895 DOI: 10.1091/mbc.e04-05-0422] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Plant peroxisomal proteins catalyze key metabolic reactions. Several peroxisome biogenesis PEROXIN (PEX) genes encode proteins acting in the import of targeted proteins necessary for these processes into the peroxisomal matrix. Most peroxisomal matrix proteins bear characterized Peroxisomal Targeting Signals (PTS1 or PTS2), which are bound by the receptors PEX5 or PEX7, respectively, for import into peroxisomes. Here we describe the isolation and characterization of an Arabidopsis peroxin mutant, pex7-1, which displays peroxisome-defective phenotypes including reduced PTS2 protein import. We also demonstrate that the pex5-1 PTS1 receptor mutant, which contains a lesion in a domain conserved among PEX7-binding proteins from various organisms, is defective not in PTS1 protein import, but rather in PTS2 protein import. Combining these mutations in a pex7-1 pex5-1 double mutant abolishes detectable PTS2 protein import and yields seedlings that are entirely sucrose-dependent for establishment, suggesting a severe block in peroxisomal fatty acid beta-oxidation. Adult pex7-1 pex5-1 plants have reduced stature and bear abnormally shaped seeds, few of which are viable. The pex7-1 pex5-1 seedlings that germinate have dramatically fewer lateral roots and often display fused cotyledons, phenotypes associated with reduced auxin response. Thus PTS2-directed peroxisomal import is necessary for normal embryonic development, seedling establishment, and vegetative growth.
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Affiliation(s)
- Andrew W Woodward
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
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