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Gao Y, Bian L, Shi J, Xu J, Xi M, Wang G. Expression of a conifer COBRA-like gene ClCOBL1 from Chinese fir (Cunninghamia lanceolata) alters the leaf architecture in tobacco. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 70:483-91. [PMID: 23851362 DOI: 10.1016/j.plaphy.2013.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 06/18/2013] [Indexed: 05/10/2023]
Abstract
The cell wall plays crucial roles in establishing the morphology of the plant cell, defence response to biotic and abiotic stresses, and mechanical properties of organs. The COBRA gene encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein that possesses the ability to modulate cellulose deposition and orient cell expansion in plant cell. We reported here the functional characterization of ClCOBL1, a conifer COBRA-like gene from the differentiating xylem of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook). ClCOBL1 belonged to a woody plant-specific clade of the COBRA protein family with several conserved motifs. Expression pattern demonstrated that ClCOBL1 was constitutively expressed but with high level in cambium region. ClCOBL1 protein was mainly located in the cell wall and plasma membrane. Overexpression of ClCOBL1 in tobacco plants yielded altered leaf adaxial-abaxial patterning and short, swollen corolla tubes. The changed leaf architecture in the ClCOBL1 overexpressors was associated with the differential expression of leaf adaxial-abaxial identity genes. Our results indicated that ClCOBL1 was involved in the determination of leaf dorsoventrality and anisotropic expansion possibly by affecting the expression of adaxial and abaxial identity genes.
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Affiliation(s)
- Yan Gao
- Shanghai Botanical Garden, No. 1111 Longwu Road, Shanghai 200231, People's Republic of China
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De Vos D, Dzhurakhalov A, Draelants D, Bogaerts I, Kalve S, Prinsen E, Vissenberg K, Vanroose W, Broeckhove J, Beemster GTS. Towards mechanistic models of plant organ growth. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3325-37. [PMID: 22371079 DOI: 10.1093/jxb/ers037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Modelling and simulation are increasingly used as tools in the study of plant growth and developmental processes. By formulating experimentally obtained knowledge as a system of interacting mathematical equations, it becomes feasible for biologists to gain a mechanistic understanding of the complex behaviour of biological systems. In this review, the modelling tools that are currently available and the progress that has been made to model plant development, based on experimental knowledge, are described. In terms of implementation, it is argued that, for the modelling of plant organ growth, the cellular level should form the cornerstone. It integrates the output of molecular regulatory networks to two processes, cell division and cell expansion, that drive growth and development of the organ. In turn, these cellular processes are controlled at the molecular level by hormone signalling. Therefore, combining a cellular modelling framework with regulatory modules for the regulation of cell division, expansion, and hormone signalling could form the basis of a functional organ growth simulation model. The current state of progress towards this aim is that the regulation of the cell cycle and hormone transport have been modelled extensively and these modules could be integrated. However, much less progress has been made on the modelling of cell expansion, which urgently needs to be addressed. A limitation of the current generation models is that they are largely qualitative. The possibilities to characterize existing and future models more quantitatively will be discussed. Together with experimental methods to measure crucial model parameters, these modelling techniques provide a basis to develop a Systems Biology approach to gain a fundamental insight into the relationship between gene function and whole organ behaviour.
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Affiliation(s)
- Dirk De Vos
- Department of Biology, University of Antwerp, Belgium
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Rodríguez-Serrano M, Romero-Puertas MC, Sparkes I, Hawes C, del Río LA, Sandalio LM. Peroxisome dynamics in Arabidopsis plants under oxidative stress induced by cadmium. Free Radic Biol Med 2009; 47:1632-9. [PMID: 19765646 DOI: 10.1016/j.freeradbiomed.2009.09.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 08/12/2009] [Accepted: 09/09/2009] [Indexed: 11/26/2022]
Abstract
Peroxisomes are organelles with an essentially oxidative metabolism that are involved in various metabolic pathways such as fatty acid beta-oxidation, photorespiration, and metabolism of reactive oxygen species (ROS) and reactive nitrogen species. These organelles are highly dynamic but there is little information about the regulation of, and the effects of environment on, peroxisome movement. In this work a stable Arabidopsis line expressing the GFP-SKL peptide targeted to peroxisomes was characterized. Peroxisome-associated fluorescence was observed in all tissues, including leaves (mesophyll and epidermal cells, trichomes, and stomata) and roots. The dynamics of peroxisomes in epidermal cells was examined by confocal laser microscope, and various types of movement were observed. The speed of movement differed depending on the plant age. Treatment of plants with CdCl(2) (100 microM) produced a significant increase in speed, which was dependent on endogenous ROS and Ca(2+), but was not related to actin cytoskeleton modifications. In light of the results obtained, it is proposed that the increase in peroxisomal motility observed in Arabidopsis plants could be a cellular mechanism of protection against the Cd-imposed oxidative stress. Other possible roles for the enhanced peroxisome movement in plant cell physiology are discussed.
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Affiliation(s)
- María Rodríguez-Serrano
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, 18080 Granada, Spain
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Mitchum MG, Sukno S, Wang X, Shani Z, Tsabary G, Shoseyov O, Davis EL. The promoter of the Arabidopsis thaliana Cel1 endo-1,4-beta glucanase gene is differentially expressed in plant feeding cells induced by root-knot and cyst nematodes. MOLECULAR PLANT PATHOLOGY 2004; 5:175-81. [PMID: 20565607 DOI: 10.1111/j.1364-3703.2004.00216.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
SUMMARY Transgenic tobacco and Arabidopsis thaliana carrying the Arabidopsis endo-1,4-beta-glucanase (EC 3.2.1.4) Cel1 promoter fused to the beta-glucuronidase (GUS) reporter gene were infected with the root-knot nematode, Meloidogyne incognita, and either the tobacco cyst nematode, Globodera tabacum (tobacco), or beet cyst nematode, Heterodera schachtii (Arabidopsis). Cel1-driven GUS expression was detected in cell elongation zones of noninfected plants and within feeding sites (giant-cells) induced in roots of both plant hosts by M. incognita. The first detectable signs of Cel1 expression within developing giant-cells occurred at the onset of giant-cell formation and continued throughout the M. incognita life cycle. UidA (Gus) transcripts were detectable within giant-cells induced in tobacco roots at 11-13 days postinoculation with M. incognita as determined by in situ mRNA hybridization. By contrast, expression of the Cel1 promoter was not detected within developing syncytia induced in tobacco or Arabidopsis roots by G. tabacum and H. schachtii, respectively, at any time point. The results demonstrate specific regulation of cell wall-degrading enzymes that may be required for cell wall modifications during feeding cell formation by sedentary endoparasitic nematodes. Differential expression of Cel1 by cyst and root-knot nematodes further supports underlying mechanistic differences in giant-cell and syncytium formation.
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Affiliation(s)
- Melissa G Mitchum
- Department of Plant Microbiology and Pathology, University of Missouri, Columbia, MO 65211, USA
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Baluska F, Wojtaszek P, Volkmann D, Barlow P. The architecture of polarized cell growth: the unique status of elongating plant cells. Bioessays 2003; 25:569-76. [PMID: 12766946 DOI: 10.1002/bies.10282] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Polarity is an inherent feature of almost all prokaryotic and eukaryotic cells. In most eukaryotic cells, growth polarity is due to the assembly of actin-based growing domains at particular locations on the cell periphery. A contrasting scenario is that growth polarity results from the establishment of non-growing domains, which are actively maintained at opposite end-poles of the cell. This latter mode of growth is common in rod-shaped bacteria and, surprisingly, also in the majority of plant cells, which elongate along the apical-basal axes of plant organs. The available data indicate that the non-growing end-pole domains of plant cells are sites of intense endocytosis and recycling. These actin-enriched end-poles serve also as signaling platforms, allowing bidirectional exchange of diverse signals along the supracellular domains of longitudinal cell files. It is proposed that these actively remodeled end-poles of elongating plant cells remotely resemble neuronal synapses.
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Affiliation(s)
- Frantisek Baluska
- Institute of Botany, Department of Plant Cell Biology, Rheinische Friedrich-Wilhelms-University of Bonn, 53115 Bonn, Germany.
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Van Gestel K, Köhler RH, Verbelen JP. Plant mitochondria move on F-actin, but their positioning in the cortical cytoplasm depends on both F-actin and microtubules. JOURNAL OF EXPERIMENTAL BOTANY 2002; 53:659-67. [PMID: 11886885 DOI: 10.1093/jexbot/53.369.659] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Mitochondrion movement and positioning was studied in elongating cultured cells of tobacco (Nicotiana tabacum L.), containing mitochondria-localized green fluorescent protein. In these cells mitochondria are either actively moving in strands of cytoplasm transversing or bordering the vacuole, or immobile positioned in the cortical layer of cytoplasm. Depletion of the cell's ATP stock with the uncoupling agent DNP shows that the movement is much more energy demanding than the positioning. The active movement is F-actin based. It is inhibited by the actin filament disrupting drug latrunculin B, the myosin ATPase inhibitor 2,3-butanedione 2-monoxime and the sulphydryl-modifying agent N-ethylmaleimide. The microtubule disrupting drug oryzalin did not affect the movement of mitochondria itself, but it slightly stimulated the recruitment of cytoplasmic strands, along which mitochondria travel. The immobile mitochondria are often positioned along parallel lines, transverse or oblique to the cell axis, in the cortical cytoplasm of elongated cells. This positioning is mainly microtubule based. After complete disruption of the F-actin, the mitochondria parked themselves into conspicuous parallel arrays transverse or oblique to the cell axis or clustered around chloroplasts and around patches and strands of endoplasmic reticulum. Oryzalin inhibited all positioning of the mitochondria in parallel arrays.
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Affiliation(s)
- K Van Gestel
- Department of Biology, University of Antwerp UIA, Universiteitsplein 1, 2610 Wilrijk, Belgium
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Baluska F, Busti E, Dolfini S, Gavazzi G, Volkmann D. Lilliputian mutant of maize lacks cell elongation and shows defects in organization of actin cytoskeleton. Dev Biol 2001; 236:478-91. [PMID: 11476586 DOI: 10.1006/dbio.2001.0333] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The maize mutant lilliputian is characterized by miniature seedling stature, reduced cell elongation, and aberrant root anatomy. Here, we document that root cells of this mutant show several defects in the organization of actin filaments (AFs). Specifically, cells within the meristem lack dense perinuclear AF baskets and fail to redistribute AFs during mitosis. In contrast, mitotic cells of wild-type roots accumulate AFs at plasma membrane-associated domains that face the mitotic spindle poles. Both mitotic and early postmitotic mutant cells fail to assemble transverse arrays of cortical AFs, which are characteristic for wild-type root cells. In addition, early postmitotic cells show aberrant distribution of endoplasmic AF bundles that are normally organized through anchorage sites at cross-walls and nuclear surfaces. In wild-type root apices, these latter AF bundles are organized in the form of symmetrically arranged conical arrays and appear to be essential for the onset of rapid cell elongation. Exposure of wild-type and cv. Alarik maize root apices to the F-actin drugs cytochalasin D and latrunculin B mimics the phenotype of lilliputian root apices. In contrast to AFs, microtubules are more or less normally organized in root cells of lilliputian mutant. Collectively, these data suggest that the LILLIPUTIAN protein, the nature of which is still unknown, impinges on plant development via its action on the actin cytoskeleton.
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Affiliation(s)
- F Baluska
- Institute of Botany, Plant Cell Biology, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany.
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Zhao J, Morozova N, Williams L, Libs L, Avivi Y, Grafi G. Two phases of chromatin decondensation during dedifferentiation of plant cells: distinction between competence for cell fate switch and a commitment for S phase. J Biol Chem 2001; 276:22772-8. [PMID: 11274191 DOI: 10.1074/jbc.m101756200] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellular dedifferentiation is the major process underlying totipotency, regeneration, and formation of new stem cell lineages in multicellular organisms. In animals it is often associated with carcinogenesis. Here, we used tobacco protoplasts (plant cells devoid of cell wall) to study changes in chromatin structure in the course of dedifferentiation of mesophyll cells. Using flow cytometry and micrococcal nuclease analyses, we identified two phases of chromatin decondensation prior to entry of cells into S phase. The first phase takes place in the course of protoplast isolation, following treatment with cell wall degrading enzymes, whereas the second occurs only after protoplasts are induced with phytohormones to re-enter the cell cycle. In the absence of hormonal application, protoplasts undergo cycles of chromatin condensation/decondensation and die. The ubiquitin proteolytic system was found indispensable for protoplast progression into S phase, being required for the second but not the first phase of chromatin decondensation. The emerging model suggests that cellular dedifferentiation proceeds by two functionally distinct phases of chromatin decondensation: the first is a transitory phase that confers competence for cell fate switch, which is followed, under appropriate conditions, by a second proteasome-dependent phase representing a commitment for the mitotic cycle. These findings might have implications for a wide range of dedifferentiation-driven cellular processes in higher eukaryotes.
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Affiliation(s)
- J Zhao
- Department of Plant Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
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