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Benevenuto RF, Seldal T, Hegland SJ, Rodriguez-Saona C, Kawash J, Polashock J. Transcriptional profiling of methyl jasmonate-induced defense responses in bilberry (Vaccinium myrtillus L.). BMC PLANT BIOLOGY 2019; 19:70. [PMID: 30755189 PMCID: PMC6373060 DOI: 10.1186/s12870-019-1650-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 01/14/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND Bilberry (Vaccinium myrtillus L.) is one of the most abundant wild berries in the Northern European ecosystems. This species plays an important ecological role as a food source for many vertebrate and invertebrate herbivores. It is also well-recognized for its bioactive compounds, particularly substances involved in natural defenses against herbivory. These defenses are known to be initiated by leaf damage (e.g. chewing by insects) and mediated by activation of the jasmonic acid (JA) signaling pathway. This pathway can be activated by exogenous application of methyl jasmonate (MeJA), the volatile derivative of JA, which is often used to stimulate plant defense responses in studies of plant-herbivore interactions at ecological, biochemical, and molecular organismal levels. As a proxy for herbivore damage, wild V. myrtillus plants were treated in the field with MeJA and changes in gene expression were compared to untreated plants. RESULTS The de novo transcriptome assembly consisted of 231,887 unigenes. Nearly 71% of the unigenes were annotated in at least one of the databases interrogated. Differentially expressed genes (DEGs), between MeJA-treated and untreated control bilberry plants were identified using DESeq. A total of 3590 DEGs were identified between the treated and control plants, with 2013 DEGs upregulated and 1577 downregulated. The majority of the DEGs identified were associated with primary and secondary metabolism pathways in plants. DEGs associated with growth (e.g. those encoding photosynthesis-related components) and reproduction (e.g. flowering control genes) were frequently down-regulated while those associated with defense (e.g. encoding enzymes involved in biosynthesis of flavonoids, lignin compounds, and deterrent/repellent volatile organic compounds) were up-regulated in the MeJA treated plants. CONCLUSIONS Ecological studies are often limited by controlled conditions to reduce the impact of environmental effects. The results from this study support the hypothesis that bilberry plants, growing in natural conditions, shift resources from growth and reproduction to defenses while in a MeJA-induced state, as when under insect attack. This study highlights the occurrence of this trade-off at the transcriptional level in a realistic field scenario and supports published field observations wherein plant growth is retarded and defenses are upregulated.
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Affiliation(s)
- Rafael Fonseca Benevenuto
- Faculty of Engineering and Science, Western Norway University of Applied Sciences, Sogndal, Norway
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Tarald Seldal
- Faculty of Engineering and Science, Western Norway University of Applied Sciences, Sogndal, Norway
| | - Stein Joar Hegland
- Faculty of Engineering and Science, Western Norway University of Applied Sciences, Sogndal, Norway
| | - Cesar Rodriguez-Saona
- Rutgers, Department of Entomology, Philip E. Marucci Center for Blueberry and Cranberry Research, The State University of New Jersey, Chatsworth, NJ USA
| | - Joseph Kawash
- Genetic Improvement of Fruits and Vegetables Lab, Philip E. Marucci Center for Blueberry and Cranberry Research, United States Department of Agriculture-Agricultural Research Service, Chatsworth, NJ USA
| | - James Polashock
- Genetic Improvement of Fruits and Vegetables Lab, Philip E. Marucci Center for Blueberry and Cranberry Research, United States Department of Agriculture-Agricultural Research Service, Chatsworth, NJ USA
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Ashraf MA, Rahman A. Cold stress response in Arabidopsis thaliana is mediated by GNOM ARF-GEF. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:500-516. [PMID: 30362633 DOI: 10.1111/tpj.14137] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 10/14/2018] [Accepted: 10/16/2018] [Indexed: 05/29/2023]
Abstract
Endosomal trafficking plays an important role in regulating plant growth and development both at optimal and stressed conditions. Cold stress response in Arabidopsis root is directly linked to inhibition of the endosomal trafficking of auxin efflux carriers. However, the cellular components that link cold stress and the endosomal trafficking remain elusive. By screening available endosomal trafficking mutants against root growth recovery response under cold stress, we identified GNOM, a SEC7 containing ARF-GEF, as a major modulator of cold response. Contrasting response of partial loss of function mutant gnomB4049/emb30-1 and the engineered Brefeldin A (BFA)-resistant GNOM line, both of which contain mutations within SEC7 domain, to cold stress at the whole-plant level highlights the importance of this domain in modulating the cold response pathway of plants. Cold stress selectively and transiently inhibits GNOM expression. The engineered point mutation at 696 amino acid position (Methionine to Leucine) that makes GNOM resistant to BFA in fact results in overexpression of GNOM both at transcriptional and translational levels, and also alters its subcellular localization. Overexpression and altered cellular localization of GNOM were found to be directly linked to conferring striking cold-resistant phenotype in Arabidopsis. Collectively, these results provide a mechanistic link between GNOM, BFA-sensitive GNOM-regulated trafficking and cold stress.
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Affiliation(s)
- Mohammad A Ashraf
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, 020-8550, Japan
| | - Abidur Rahman
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, 020-8550, Japan
- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
- Agro-Innovation Center, Iwate University, Morioka, Japan
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53
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Zwiewka M, Bielach A, Tamizhselvan P, Madhavan S, Ryad EE, Tan S, Hrtyan MN, Dobrev P, Vankovï R, Friml J, Tognetti VB. Root Adaptation to H2O2-Induced Oxidative Stress by ARF-GEF BEN1- and Cytoskeleton-Mediated PIN2 Trafficking. PLANT & CELL PHYSIOLOGY 2019; 60:255-273. [PMID: 30668780 DOI: 10.1093/pcp/pcz001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 01/03/2019] [Indexed: 05/12/2023]
Abstract
Abiotic stress poses constant challenges for plant survival and is a serious problem for global agricultural productivity. On a molecular level, stress conditions result in elevation of reactive oxygen species (ROS) production causing oxidative stress associated with oxidation of proteins and nucleic acids as well as impairment of membrane functions. Adaptation of root growth to ROS accumulation is facilitated through modification of auxin and cytokinin hormone homeostasis. Here, we report that in Arabidopsis root meristem, ROS-induced changes of auxin levels correspond to decreased abundance of PIN auxin efflux carriers at the plasma membrane (PM). Specifically, increase in H2O2 levels affects PIN2 endocytic recycling. We show that the PIN2 intracellular trafficking during adaptation to oxidative stress requires the function of the ADP-ribosylation factor (ARF)-guanine-nucleotide exchange factor (GEF) BEN1, an actin-associated regulator of the trafficking from the PM to early endosomes and, presumably, indirectly, trafficking to the vacuoles. We propose that H2O2 levels affect the actin dynamics thus modulating ARF-GEF-dependent trafficking of PIN2. This mechanism provides a way how root growth acclimates to stress and adapts to a changing environment.
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Affiliation(s)
- Marta Zwiewka
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
| | - Agnieszka Bielach
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
| | - Prashanth Tamizhselvan
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
| | - Sharmila Madhavan
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
| | - Eman Elrefaay Ryad
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
| | - Shutang Tan
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
| | - Mï Nika Hrtyan
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
| | - Petre Dobrev
- Institute of Experimental Botany Czech Acad. Sci, Laboratory of Hormonal Regulations in Plants, Rozvojov� 263, Prague 6, Czech Republic
| | - Radomira Vankovï
- Institute of Experimental Botany Czech Acad. Sci, Laboratory of Hormonal Regulations in Plants, Rozvojov� 263, Prague 6, Czech Republic
| | - Jiřï Friml
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Vanesa B Tognetti
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Brno, Czech Republic
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54
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Paponov IA, Friz T, Budnyk V, Teale W, Wüst F, Paponov M, Al-Babili S, Palme K. Natural Auxin Does Not Inhibit Brefeldin A Induced PIN1 and PIN2 Internalization in Root Cells. FRONTIERS IN PLANT SCIENCE 2019; 10:574. [PMID: 31143194 PMCID: PMC6521567 DOI: 10.3389/fpls.2019.00574] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 04/16/2019] [Indexed: 05/20/2023]
Abstract
The vesicle trafficking inhibitor Brefeldin A (BFA) changes the localization of plasma membrane localized PINs, proteins that function as polar auxin efflux carriers, by inducing their accumulation within cells. Pretreatment with the synthetic auxin 1-NAA reduces this BFA-induced PIN internalization, suggesting that auxinic compounds inhibit the endocytosis of PIN proteins. However, the most important natural auxin, IAA, did not substantially inhibit PIN internalization unless a supplementary antioxidant, butylated hydroxytoluene (BHT), was also included in the incubation medium. We asked whether the relatively small inhibition caused by IAA alone could be explained by its instability in the incubation solution or whether IAA might interact with BHT to inhibit endocytosis. Analysis of the IAA concentration in the incubation solution and of DR5 reporter activity in the roots showed that IAA is both stable and active in the medium. Therefore, IAA degradation was not able to explain the inability of IAA to inhibit endocytosis. Furthermore, when applied in the absence of auxin, BHT caused a strong increase in the rate of PIN1 internalization and a weaker increase in the rate of PIN2 internalization. These increases were unaffected by the simultaneous application of IAA, further indicating that endocytosis is not inhibited by the natural auxin IAA under physiologically relevant conditions. Endocytosis was inhibited at the same rate with 2-NAA, an inactive auxin analog, as was observed with 1-NAA and more strongly than with natural auxins, supporting the idea that this inhibition is not auxin specific.
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Affiliation(s)
- Ivan A. Paponov
- Faculty of Biology, Institute of Biology II/Botany, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Food Production and Society, Ås, Norway
- *Correspondence: Ivan A. Paponov,
| | - Tatyana Friz
- Faculty of Biology, Institute of Biology II/Botany, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Vadym Budnyk
- Faculty of Biology, Institute of Biology II/Botany, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - William Teale
- Faculty of Biology, Institute of Biology II/Botany, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Florian Wüst
- Faculty of Biology, Institute of Biology II/Cell Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Martina Paponov
- Faculty of Biology, Institute of Biology II/Botany, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Salim Al-Babili
- Faculty of Biology, Institute of Biology II/Cell Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Klaus Palme
- Faculty of Biology, Institute of Biology II/Botany, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
- Centre of Biological Systems Analysis, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
- Klaus Palme,
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55
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Dong Q, Zhang Z, Liu Y, Tao LZ, Liu H. FERONIA regulates auxin-mediated lateral root development and primary root gravitropism. FEBS Lett 2018; 593:97-106. [PMID: 30417333 DOI: 10.1002/1873-3468.13292] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 12/23/2022]
Abstract
The Arabidopsis FERONIA (FER) receptor kinase is a key hub of cell signaling networks mediating various hormone, stress, and immune responses. Previous studies have shown that FER functions correlate with auxin responses, but the underlying molecular mechanism is unknown. Here, we demonstrate that the primary root of the fer-4 mutant displays increased lateral root branching and a delayed gravitropic response, which are associated with polar auxin transport (PAT). Our data suggest that aberrant PIN2 polarity is responsible for the delayed gravitropic response in fer-4. Furthermore, the diminished F-actin cytoskeleton in fer-4 implies that FER modulates F-actin-mediated PIN2 polar localization. Our findings provide new insights into the function of FER in PAT.
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Affiliation(s)
- QingKun Dong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - ZhiWei Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - YuTing Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Li-Zhen Tao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - HuiLi Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
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56
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Youssef C, Bizet F, Bastien R, Legland D, Bogeat-Triboulot MB, Hummel I. Quantitative dissection of variations in root growth rate: a matter of cell proliferation or of cell expansion? JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:5157-5168. [PMID: 30053124 PMCID: PMC6184812 DOI: 10.1093/jxb/ery272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 07/16/2018] [Indexed: 05/24/2023]
Abstract
Plant organ growth results from cell production and cell expansion. Deciphering the contribution of each of these processes to growth rate is an important issue in developmental biology. Here, we investigated the cellular processes governing root elongation rate, considering two sources of variation: genotype and disturbance by chemicals (NaCl, polyethylene glycol, H2O2, abscisic acid). Exploiting the adventitious rooting capacity of the Populus genus, and using time-lapse imaging under infrared-light, particle image velocimetry, histological analysis, and kinematics, we quantified the cellular processes involved in root growth variation, and analysed the covariation patterns between growth parameters. The rate of cell production by the root apical meristem and the number of dividing cells were estimated in vivo without destructive measurement. We found that the rate of cell division contributed more to the variation in cell production rate than the number of dividing cells. Regardless of the source of variation, the length of the elongation zone was the best proxy for growth rate, summarizing rates of cell production and cell elongation into a single parameter. Our results demonstrate that cell production rate is the main driver of growth rate, whereas elemental elongation rate is a key driver of short-term growth adjustments.
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Affiliation(s)
- Chvan Youssef
- Université de Lorraine, AgroParisTech, INRA, UMR Silva, Nancy, France
| | - François Bizet
- UMR PIAF, INRA, Université Clermont Auvergne, Aubière, France
| | - Renaud Bastien
- Department of Collective Behaviour, Max Planck Institute for Ornithology, University of Konstanz, Konstanz, Germany
| | - David Legland
- UMR Biopolymers, Interactions and Assemblies, INRA, Nantes, France
| | | | - Irène Hummel
- Université de Lorraine, AgroParisTech, INRA, UMR Silva, Nancy, France
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57
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Zhang J, Chen J, Wang L, Zhao S, Li J, Liu B, Li H, Qi X, Zheng H, Lu M. AtBET5 is essential for exine pattern formation and apical meristem organization in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 274:231-241. [PMID: 30080609 DOI: 10.1016/j.plantsci.2018.05.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 05/29/2018] [Accepted: 05/30/2018] [Indexed: 06/08/2023]
Abstract
BET5 is a component of trafficking protein particle (TRAPP) which has been studied extensively in non-plant organisms where they are involved in membrane trafficking within Golgi and between Golgi and early endosomes. Recent analysis of TRAPP in different classes of organisms indicates that TRAPP function might exhibit differences among organisms. A single copy of the BET5 gene named AtBET5 was found in the Arabidopsis genome based on sequence similarity. Developmental phenotype and the underlying mechanisms have been characterized upon transcriptional knock-down lines generated by both T-DNA insertion and RNAi. Pollen grains of the T-DNA insertional line present reduced fertility and pilate exine instead of tectate exine. Perturbation of the AtBET5 expression by RNAi leads to apical meristematic organization defects and reduced fertility as well. The reduced fertility was due to the pollination barrier caused by an altered composition and structure of pollen walls. Auxin response in root tip cells is altered and there is a severe disruption in polar localization of PIN1-GFP, but to a less extent of PIN2-GFP in the root tips, which causes the apical meristematic organization defects and might also be responsible for the secretion of sporopollenin precursor or polar targeting of sporopollenin precursor transporters.
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Affiliation(s)
- Jin Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China
| | - Jun Chen
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China; Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, QC, H3A 1B1, Canada
| | - Lijuan Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China
| | - Shutang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China
| | - Jianbo Li
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China
| | - Bobin Liu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China
| | - Hongying Li
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China
| | - Xingyun Qi
- Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, QC, H3A 1B1, Canada
| | - Huanquan Zheng
- Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, QC, H3A 1B1, Canada.
| | - Mengzhu Lu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100 091, China.
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58
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Li X, Wang L, Wang S, Yang Q, Zhou Q, Huang X. A preliminary analysis of the effects of bisphenol A on the plant root growth via changes in endogenous plant hormones. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 150:152-158. [PMID: 29274504 DOI: 10.1016/j.ecoenv.2017.12.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 11/20/2017] [Accepted: 12/14/2017] [Indexed: 05/12/2023]
Abstract
Bisphenol A (BPA) is ubiquitous in the environment worldwide, affecting plant growth and development. Endogenous plant hormones serve as switches that regulate plant growth and development. However, plants have different physiological requirements and environmental adaptive capacities during the different growth stages. Here, we investigated the effects of BPA on soybean (Glycine max L.) root growth at the three growth stages and analyzed the mechanisms underlying the effects of BPA on the root growth by assessing changes in endogenous hormone. The results showed that low concentration of BPA (1.5mgL-1) improved root growth (except at the seed-filling stage), increased indole-3-acetic acid (IAA) content at the first two growth stages, and increased zeatin (ZT) content and decreased gibberellic acid (GA3) content at the seedling stage. But low concentration of BPA caused decreased ethylene (ETH) contents and constant abscisic acid (ABA) content at all three stages. However, BPA at moderate and high concentrations (6.0 and 12.0mgL-1) inhibited root growth, causing the decreased IAA, GA3 and ETH contents and increased ABA content at all three growth stages. The change degrees of above indices were weakened with prolonging the growth stages. After BPA withdrawal, both the root growth and the hormone contents recovered (with the exception of ZT and ETH), and the recovery degrees had negative correlation with the BPA exposure concentration and had positive correlation with the growth stage. Changes in residual BPA content in the roots were also observed at different BPA concentrations and different growth stages. Our results demonstrated the effects of BPA on root growth were related to BPA-induced changes in hormone, which performed differently at various growth stages.
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Affiliation(s)
- Xingyi Li
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Lihong Wang
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Shengman Wang
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Qing Yang
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China
| | - Qing Zhou
- State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, Suzhou University of Science and Technology, Suzhou 215009, China.
| | - Xiaohua Huang
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China.
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Lee S, I. Sergeeva L, Vreugdenhil D. Natural variation of hormone levels in Arabidopsis roots and correlations with complex root architecture. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2018; 60:292-309. [PMID: 29205819 PMCID: PMC5947113 DOI: 10.1111/jipb.12617] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 12/01/2017] [Indexed: 06/07/2023]
Abstract
Studies on natural variation are an important tool to unravel the genetic basis of quantitative traits in plants. Despite the significant roles of phytohormones in plant development, including root architecture, hardly any studies have been done to investigate natural variation in endogenous hormone levels in plants. Therefore, in the present study a range of hormones were quantified in root extracts of thirteen Arabidopsis thaliana accessions using a ultra performance liquid chromatography triple quadrupole mass spectrometer. Root system architecture of the set of accessions was quantified, using a new parameter (mature root unit) for complex root systems, and correlated with the phytohormone data. Significant variations in phytohormone levels among the accessions were detected, but were remarkably small, namely less than three-fold difference between extremes. For cytokinins, relatively larger variations were found for ribosides and glucosides, as compared to the free bases. For root phenotyping, length-related traits-lateral root length and total root length-showed larger variations than lateral root number-related ones. For root architecture, antagonistic interactions between hormones, for example, indole-3-acetic acid to trans-zeatin were detected in correlation analysis. These findings provide conclusive evidence for the presence of natural variation in phytohormone levels in Arabidopsis roots, suggesting that quantitative genetic analyses are feasible.
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Affiliation(s)
- Sangseok Lee
- Laboratory of Plant PhysiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenThe Netherlands
- Gyeongsangbuk‐Do Agricultural Research & Extension Services Centre136 Gil‐14Chilgokjungang‐daeroDaeguSouth Korea
| | - Lidiya I. Sergeeva
- Laboratory of Plant PhysiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenThe Netherlands
| | - Dick Vreugdenhil
- Laboratory of Plant PhysiologyWageningen University & ResearchDroevendaalsesteeg 16708 PBWageningenThe Netherlands
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60
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Liao C, Weijers D. A toolkit for studying cellular reorganization during early embryogenesis in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:963-976. [PMID: 29383853 PMCID: PMC5887935 DOI: 10.1111/tpj.13841] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 05/02/2023]
Abstract
Considerable progress has been made in understanding the influence of physical and genetic factors on the patterns of cell division in various model systems. However, how each of these factors directs changes in subcellular structures has remained unclear. Generic machineries for the execution of cell expansion and division have been characterized, but how these are influenced by genetic regulators and physical cell properties remains an open question. To a large degree, the complexity of growing post-embryonic tissues and a lack of precise predictability have prevented the extraction of rigid correlations between subcellular structures and future orientation of cell division. The Arabidopsis embryo offers an exquisitely predictable and simple model for studying such correlations, but so far the tools and methodology for studying subcellular structures in the early embryo have been lacking. Here, we describe a set of markers to visualize a range of subcellular structures in the early Arabidopsis embryo. We have designed a series of fluorescent cellular reporters optimized for embryos, and demonstrate the effectiveness of using these 'ACE' reporters with simple three-dimensional imaging procedures that preserve delicate cellular structures. We describe the ontogeny of subcellular structures in the early embryo and find that central/peripheral cell polarity is established much earlier than suspected. In addition, we show that the actin and microtubule cytoskeleton has distinct topologies in the embryo. These tools and methods will allow detailed analysis of the events of cellular reorganization that underlie morphogenesis in the Arabidopsis embryo.
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Affiliation(s)
- Che‐Yang Liao
- Laboratory of BiochemistryWageningen UniversityStippeneng 46708WE Wageningenthe Netherlands
| | - Dolf Weijers
- Laboratory of BiochemistryWageningen UniversityStippeneng 46708WE Wageningenthe Netherlands
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Hodge CD, Spyracopoulos L, Glover JNM. Ubc13: the Lys63 ubiquitin chain building machine. Oncotarget 2018; 7:64471-64504. [PMID: 27486774 PMCID: PMC5325457 DOI: 10.18632/oncotarget.10948] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/19/2016] [Indexed: 12/25/2022] Open
Abstract
Ubc13 is an ubiquitin E2 conjugating enzyme that participates with many different E3 ligases to form lysine 63-linked (Lys63) ubiquitin chains that are critical to signaling in inflammatory and DNA damage response pathways. Recent studies have suggested Ubc13 as a potential therapeutic target for intervention in various human diseases including several different cancers, alleviation of anti-cancer drug resistance, chronic inflammation, and viral infections. Understanding a potential therapeutic target from different angles is important to assess its usefulness and potential pitfalls. Here we present a global review of Ubc13 from its structure, function, and cellular activities, to its natural and chemical inhibition. The aim of this article is to review the literature that directly implicates Ubc13 in a biological function, and to integrate structural and mechanistic insights into the larger role of this critical E2 enzyme. We discuss observations of multiple Ubc13 structures that suggest a novel mechanism for activation of Ubc13 that involves conformational change of the active site loop.
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Affiliation(s)
- Curtis D Hodge
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Leo Spyracopoulos
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - J N Mark Glover
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
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62
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Teale W, Palme K. Naphthylphthalamic acid and the mechanism of polar auxin transport. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:303-312. [PMID: 28992080 DOI: 10.1093/jxb/erx323] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Our current understanding of how plants move auxin through their tissues is largely built on the use of polar auxin transporter inhibitors. Although the most important proteins that mediate auxin transport and its regulation have probably all been identified and the mapping of their interactions is well underway, mechanistically we are still surprisingly far away from understanding how auxin is transported. Such an understanding will only emerge after new data are placed in the context of the wealth of physiological data on which they are founded. This review will look back over the use of a key inhibitor called naphthylphthalamic acid (NPA) and outline its contribution to our understanding of the molecular mechanisms of polar auxin transport, before proceeding to speculate on how its use is likely still to be informative.
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Affiliation(s)
- William Teale
- Institute of Biology II, Albert-Ludwigs-Universität of Freiburg, Germany
| | - Klaus Palme
- Institute of Biology II, Albert-Ludwigs-Universität of Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universität Freiburg, Germany
- Freiburg Institute of Advanced Sciences (FRIAS), Albert-Ludwigs-Universität Freiburg, Germany
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63
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Šimkūnas A, Valašinaitė S, Denisov V. Comparative systemic analysis of the cellular growth of leaves and roots in controlled conditions. JOURNAL OF PLANT PHYSIOLOGY 2018; 220:128-135. [PMID: 29175544 DOI: 10.1016/j.jplph.2017.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 06/07/2023]
Abstract
The comparative cytological analysis of the leaf/root growth of Lolium multiflorum has been performed. It revealed differences of the mentioned above/under-ground organs that express the whole plant's polarity. To perform accurate and simultaneous growth comparison a climatic-hydroponics system has been implemented. A sharp increase in the epidermis cell length of the leaf meristem has been detected for the first time. It allows the proposal of a new way to demarcate the boundary of the meristem and suggests a lengthed leaf meristem, that is 4 times longer than the root meristem. As the cell cycle duration in leaves and roots is similar, the prolonged leaf meristem and a higher leaf growth rate could be determined by the longer life span of cells in meristem, resulting in more cell cycles. The prolonged meristem provides a significantly higher leaf growth rate, ensuring a functional balance with roots. The elongation zone of the roots is significantly shorter than in leaves, which is caused by the larger relative root elongation rate and the slower meristemic root growth rate. The novelty formulated, i.e., the prolonged leaf meristem, opens theoretical perspectives in longitudinal zonation, in finding molecular markers and provides practical significance for the biology of productivity.
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Affiliation(s)
- Alvydas Šimkūnas
- Marine Technology and Natural Sciences Faculty, Klaipeda University, Bijūnų str. 17, 91225 Klaipėda, Lithuania.
| | - Sandra Valašinaitė
- Marine Technology and Natural Sciences Faculty, Klaipeda University, Bijūnų str. 17, 91225 Klaipėda, Lithuania.
| | - Vitalij Denisov
- Marine Technology and Natural Sciences Faculty, Klaipeda University, Bijūnų str. 17, 91225 Klaipėda, Lithuania.
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64
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Paponov IA, Dindas J, Król E, Friz T, Budnyk V, Teale W, Paponov M, Hedrich R, Palme K. Auxin-Induced Plasma Membrane Depolarization Is Regulated by Auxin Transport and Not by AUXIN BINDING PROTEIN1. FRONTIERS IN PLANT SCIENCE 2018; 9:1953. [PMID: 30705682 PMCID: PMC6344447 DOI: 10.3389/fpls.2018.01953] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/14/2018] [Indexed: 05/20/2023]
Abstract
Auxin is a molecule, which controls many aspects of plant development through both transcriptional and non-transcriptional signaling responses. AUXIN BINDING PROTEIN1 (ABP1) is a putative receptor for rapid non-transcriptional auxin-induced changes in plasma membrane depolarization and endocytosis rates. However, the mechanism of ABP1-mediated signaling is poorly understood. Here we show that membrane depolarization and endocytosis inhibition are ABP1-independent responses and that auxin-induced plasma membrane depolarization is instead dependent on the auxin influx carrier AUX1. AUX1 was itself not involved in the regulation of endocytosis. Auxin-dependent depolarization of the plasma membrane was also modulated by the auxin efflux carrier PIN2. These data establish a new connection between auxin transport and non-transcriptional auxin signaling.
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Affiliation(s)
- Ivan A. Paponov
- Faculty of Biology, Institute of Biology II/Molecular Plant Physiology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
- Norwegian Institute of Bioeconomy Research, Klepp, Norway
- *Correspondence: Ivan A. Paponov,
| | - Julian Dindas
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Elżbieta Król
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Tatyana Friz
- Faculty of Biology, Institute of Biology II/Molecular Plant Physiology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Vadym Budnyk
- Faculty of Biology, Institute of Biology II/Molecular Plant Physiology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
- Centre of Biological Systems Analysis and BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - William Teale
- Faculty of Biology, Institute of Biology II/Molecular Plant Physiology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Martina Paponov
- Faculty of Biology, Institute of Biology II/Molecular Plant Physiology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Klaus Palme
- Faculty of Biology, Institute of Biology II/Molecular Plant Physiology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
- Renal Division, Department of Medicine, University Freiburg Medical Center, Freiburg, Germany
- Klaus Palme,
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65
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Paez-Garcia A, Sparks JA, de Bang L, Blancaflor EB. Plant Actin Cytoskeleton: New Functions from Old Scaffold. PLANT CELL MONOGRAPHS 2018. [DOI: 10.1007/978-3-319-69944-8_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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66
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Imaging cellulose synthase motility during primary cell wall synthesis in the grass Brachypodium distachyon. Sci Rep 2017; 7:15111. [PMID: 29118446 PMCID: PMC5678151 DOI: 10.1038/s41598-017-14988-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 10/19/2017] [Indexed: 12/02/2022] Open
Abstract
The mechanism of cellulose synthesis has been studied by characterizing the motility of cellulose synthase complexes tagged with a fluorescent protein; however, this approach has been used exclusively on the hypocotyl of Arabidopsis thaliana. Here we characterize cellulose synthase motility in the model grass, Brachypodium distachyon. We generated lines in which mEGFP is fused N-terminal to BdCESA3 or BdCESA6 and which grew indistinguishably from the wild type (Bd21-3) and had dense fluorescent puncta at or near the plasma membrane. Measured with a particle tracking algorithm, the average speed of GFP-BdCESA3 particles in the mesocotyl was 164 ± 78 nm min−1 (error gives standard deviation [SD], n = 1451 particles). Mean speed in the root appeared similar. For comparison, average speed in the A. thaliana hypocotyl expressing GFP-AtCESA6 was 184 ± 86 nm min−1 (n = 2755). For B. distachyon, we quantified root diameter and elongation rate in response to inhibitors of cellulose (dichlorobenylnitrile; DCB), microtubules (oryzalin), or actin (latrunculin B). Neither oryzalin nor latrunculin affected the speed of CESA complexes; whereas, DCB reduced average speed by about 50% in B. distachyon and by about 35% in A. thaliana. Evidently, between these species, CESA motility is well conserved.
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67
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Huang X, Maisch J, Nick P. Sensory role of actin in auxin-dependent responses of tobacco BY-2. JOURNAL OF PLANT PHYSIOLOGY 2017; 218:6-15. [PMID: 28763708 DOI: 10.1016/j.jplph.2017.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 05/09/2023]
Abstract
Polar auxin transport depends on the polar localization of auxin-efflux carriers. The cycling of these carriers between cell interior and plasma membrane depends on actin. The dynamic of actin not only affects auxin transport, but also changes the auxin-responsiveness. To study the potential link between auxin responsiveness and actin dynamics, we investigated developmental responses of the non-transformed BY-2 (Nicotiana tabacum L. cv Bright Yellow 2) cell line and the transgenic BY-2 strain GF11 (stably transformed BY-2 cells with a GFP-fimbrin actin-binding domain 2 construct). The developmental process was divided into three distinct stages: cell cycling, cell elongation and file disintegration. Several phenotypes were measured to monitor the cellular responses to different concentrations of exogenous natural auxin (Indole-3-acetic acid, IAA). We found that auxin stimulated and prolonged the mitotic activity, and delayed the exit from the proliferation phase. However, both responses were suppressed in the GF11 line. At the stationary phase of the cultivation cycle, auxin strongly accelerated the cell file disintegration. Interestingly, it was not suppressed but progressed to a more complete disintegration in the GF11 line. During the cultivation cycle, we also followed the organization of actin in the GF11 line and did not detect any significant difference in actin organization from untreated control or exogenous IAA treatment. Therefore, our findings indicate that the specific differences observed in the GF11 line must be linked with a function of actin that is not structural. It means that there is a sensory role of actin for auxin signaling.
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Affiliation(s)
- Xiang Huang
- Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg. 4, Gbd. 30.43, (5. OG), 76131 Karlsruhe, Germany.
| | - Jan Maisch
- Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg. 4, Gbd. 30.43, (5. OG), 76131 Karlsruhe, Germany.
| | - Peter Nick
- Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg. 4, Gbd. 30.43, (5. OG), 76131 Karlsruhe, Germany.
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68
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Cheng ML, Lo SF, Hsiao AS, Hong YF, Yu SM, Ho THD. Ectopic Expression of WINDING 1 Leads to Asymmetrical Distribution of Auxin and a Spiral Phenotype in Rice. PLANT & CELL PHYSIOLOGY 2017; 58:1494-1506. [PMID: 28922746 DOI: 10.1093/pcp/pcx088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
Ectopic expression of the rice WINDING 1 (WIN1) gene leads to a spiral phenotype only in shoots but not in roots. Rice WIN1 belongs to a specific class of proteins in cereal plants containing a Bric-a-Brac/Tramtrack/Broad (BTB) complex, a non-phototropic hypocotyl 3 (NPH3) domain and a coiled-coil motif. The WIN1 protein is predominantly localized to the plasma membrane, but is also co-localized to plasmodesmata, where it exhibits a punctate pattern. It is observed that WIN1 is normally expressed in roots and the shoot-root junction, but not in the rest of shoots. In roots, WIN1 is largely localized to the apical and basal sides of cells. However, upon ectopic expression, WIN1 appears on the longitudinal sides of leaf sheath cells, correlated with the appearance of a spiral phenotype in shoots. Despite the spiral phenotype, WIN1-overexpressing plants exhibit a normal phototropic response. Although treatments with exogenous auxins or a polar auxin transport inhibitor do not alter the spiral phenotype, the excurvature side has a higher auxin concentration than the incurvature side. Furthermore, actin filaments are more prominent in the excurvature side than in the incurvature side, which correlates with cell size differences between these two sides. Interestingly, ectopic expression of WIN1 does not cause either unequal auxin distribution or actin filament differences in roots, so a spiral phenotype is not observed in roots. The action of WIN1 appears to be different from that of other proteins causing a spiral phenotype, and it is likely that WIN1 is involved in 1-N-naphthylphthalamic acid-insensitive plasmodesmata-mediated auxin transport.
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Affiliation(s)
- Ming-Lung Cheng
- Department of Life Sciences, National Cheng Kung University, Tainan 701, Taiwan, ROC
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Shuen-Fang Lo
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - An-Shan Hsiao
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Ya-Fang Hong
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Su-May Yu
- Department of Life Sciences, National Cheng Kung University, Tainan 701, Taiwan, ROC
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan, ROC
- Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Tuan-Hua David Ho
- Department of Life Sciences, National Cheng Kung University, Tainan 701, Taiwan, ROC
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan, ROC
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
- Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan, ROC
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69
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Abstract
The organic electronic ion pump (OEIP) provides flow-free and accurate delivery of small signaling compounds at high spatiotemporal resolution. To date, the application of OEIPs has been limited to delivery of nonaromatic molecules to mammalian systems, particularly for neuroscience applications. However, many long-standing questions in plant biology remain unanswered due to a lack of technology that precisely delivers plant hormones, based on cyclic alkanes or aromatic structures, to regulate plant physiology. Here, we report the employment of OEIPs for the delivery of the plant hormone auxin to induce differential concentration gradients and modulate plant physiology. We fabricated OEIP devices based on a synthesized dendritic polyelectrolyte that enables electrophoretic transport of aromatic substances. Delivery of auxin to transgenic Arabidopsis thaliana seedlings in vivo was monitored in real time via dynamic fluorescent auxin-response reporters and induced physiological responses in roots. Our results provide a starting point for technologies enabling direct, rapid, and dynamic electronic interaction with the biochemical regulation systems of plants.
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70
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Abts W, Vandenbussche B, De Proft MP, Van de Poel B. The Role of Auxin-Ethylene Crosstalk in Orchestrating Primary Root Elongation in Sugar Beet. FRONTIERS IN PLANT SCIENCE 2017; 8:444. [PMID: 28424722 PMCID: PMC5371662 DOI: 10.3389/fpls.2017.00444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 03/14/2017] [Indexed: 05/05/2023]
Abstract
It is well-established in Arabidopsis and other species that ethylene inhibits root elongation through the action of auxin. In sugar beet (Beta vulgaris L.) ethylene promotes root elongation in a concentration dependent manner. However, the crosstalk between ethylene and auxin remains unknown during sugar beet seedling development. Our experiments have shown that exogenously applied auxin (indole-3-acetic acid; IAA) also stimulates root elongation. We also show that auxin promotes ethylene biosynthesis leading to longer roots. We have further demonstrated that the auxin treatment stimulates ethylene production by redirecting the pool of available 1-aminocyclopropane-1-carboxylic acid (ACC) toward ethylene instead of malonyl-ACC (MACC) resulting in a prolonged period of high rates of ethylene production and subsequently a longer root. On the other hand we have also shown that endogenous IAA levels were not affected by an ACC treatment during germination. All together our findings suggest that the general model for auxin-ethylene crosstalk during early root development, where ethylene controls auxin biosynthesis and transport, does not occur in sugar beet. On the contrary, we have shown that the opposite, where auxin stimulates ethylene biosynthesis, is true for sugar beet root development.
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Affiliation(s)
- Willem Abts
- Division of Crop Biotechnics, Department of Biosystems, University of LeuvenLeuven, Belgium
| | | | - Maurice P. De Proft
- Division of Crop Biotechnics, Department of Biosystems, University of LeuvenLeuven, Belgium
| | - Bram Van de Poel
- Division of Crop Biotechnics, Department of Biosystems, University of LeuvenLeuven, Belgium
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71
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Yang J, Yuan Z, Meng Q, Huang G, Périn C, Bureau C, Meunier AC, Ingouff M, Bennett MJ, Liang W, Zhang D. Dynamic Regulation of Auxin Response during Rice Development Revealed by Newly Established Hormone Biosensor Markers. FRONTIERS IN PLANT SCIENCE 2017; 8:256. [PMID: 28326089 PMCID: PMC5339295 DOI: 10.3389/fpls.2017.00256] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/10/2017] [Indexed: 05/18/2023]
Abstract
The hormone auxin is critical for many plant developmental processes. Unlike the model eudicot plant Arabidopsis (Arabidopsis thaliana), auxin distribution and signaling in rice tissues has not been systematically investigated due to the absence of suitable auxin response reporters. In this study we observed the conservation of auxin signaling components between Arabidopsis and model monocot crop rice (Oryza sativa), and generated complementary types of auxin biosensor constructs, one derived from the Aux/IAA-based biosensor DII-VENUS but constitutively driven by maize ubiquitin-1 promoter, and the other termed DR5-VENUS in which a synthetic auxin-responsive promoter (DR5rev ) was used to drive expression of the yellow fluorescent protein (YFP). Using the obtained transgenic lines, we observed that during the vegetative development, accumulation of DR5-VENUS signal was at young and mature leaves, tiller buds and stem base. Notably, abundant DR5-VENUS signals were observed in the cytoplasm of cortex cells surrounding lateral root primordia (LRP) in rice. In addition, auxin maxima and dynamic re-localization were seen at the initiation sites of inflorescence and spikelet primordia including branch meristems (BMs), female and male organs. The comparison of these observations among Arabidopsis, rice and maize suggests the unique role of auxin in regulating rice lateral root emergence and reproduction. Moreover, protein localization of auxin transporters PIN1 homologs and GFP tagged OsAUX1 overlapped with DR5-VENUS during spikelet development, helping validate these auxin response reporters are reliable markers in rice. This work firstly reveals the direct correspondence between auxin distribution and rice reproductive and root development at tissue and cellular level, and provides high-resolution auxin tools to probe fundamental developmental processes in rice and to establish links between auxin, development and agronomical traits like yield or root architecture.
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Affiliation(s)
- Jing Yang
- Key Laboratory of Systems Biomedicine, Ministry of Education, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong UniversityShanghai, China
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University–University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China
| | - Zheng Yuan
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University–University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China
| | - Qingcai Meng
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University–University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China
| | - Guoqiang Huang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University–University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China
| | | | | | | | | | - Malcolm J. Bennett
- Centre for Plant Integrative Biology, School of Biosciences, University of NottinghamSutton Bonington, UK
| | - Wanqi Liang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University–University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China
| | - Dabing Zhang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University–University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong UniversityShanghai, China
- School of Agriculture, Food and Wine, University of AdelaideUrrbrae, SA, Australia
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72
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Wang M, Schoettner M, Xu S, Paetz C, Wilde J, Baldwin IT, Groten K. Catechol, a major component of smoke, influences primary root growth and root hair elongation through reactive oxygen species-mediated redox signaling. THE NEW PHYTOLOGIST 2017; 213:1755-1770. [PMID: 27878986 DOI: 10.1111/nph.14317] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/29/2016] [Indexed: 06/06/2023]
Abstract
Nicotiana attenuata germinates from long-lived seedbanks in native soils after fires. Although smoke signals have been known to break seed dormancy, whether they also affect seedling establishment and root development remains unclear. In order to test this, seedlings were treated with smoke solutions. Seedlings responded in a dose-dependent manner with significantly increased primary root lengths, due mainly to longitudinal cell elongation, increased numbers of lateral roots and impaired root hair development. Bioassay-driven fractionations and NMR were used to identify catechol as the main active compound for the smoke-induced root phenotype. The transcriptome analysis revealed that mainly genes related to auxin biosynthesis and redox homeostasis were altered after catechol treatment. However, histochemical analyses of reactive oxygen species (ROS) and the inability of auxin applications to rescue the phenotype clearly indicated that highly localized changes in the root's redox-status, rather than in levels of auxin, are the primary effector. Moreover, H2 O2 application rescued the phenotype in a dose-dependent manner. Chemical cues in smoke not only initiate seed germination, but also influence seedling root growth; understanding how these cues work provides new insights into the molecular mechanisms by which plants adapt to post-fire environments.
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Affiliation(s)
- Ming Wang
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Matthias Schoettner
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Shuqing Xu
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Christian Paetz
- NMR Group, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Julia Wilde
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Ian T Baldwin
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Karin Groten
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
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73
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Takahashi M, Umetsu K, Oono Y, Higaki T, Blancaflor EB, Rahman A. Small acidic protein 1 and SCF TIR1 ubiquitin proteasome pathway act in concert to induce 2,4-dichlorophenoxyacetic acid-mediated alteration of actin in Arabidopsis roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 89:940-956. [PMID: 27885735 DOI: 10.1111/tpj.13433] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 11/09/2016] [Accepted: 11/14/2016] [Indexed: 06/06/2023]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D), a functional analogue of auxin, is used as an exogenous source of auxin as it evokes physiological responses like the endogenous auxin, indole-3-acetic acid (IAA). Previous molecular analyses of the auxin response pathway revealed that IAA and 2,4-D share a common mode of action to elicit downstream physiological responses. However, recent findings with 2,4-D-specific mutants suggested that 2,4-D and IAA might also use distinct pathways to modulate root growth in Arabidopsis. Using genetic and cellular approaches, we demonstrate that the distinct effects of 2,4-D and IAA on actin filament organization partly dictate the differential responses of roots to these two auxin analogues. 2,4-D but not IAA altered the actin structure in long-term and short-term assays. Analysis of the 2,4-D-specific mutant aar1-1 revealed that small acidic protein 1 (SMAP1) functions positively to facilitate the 2,4-D-induced depolymerization of actin. The ubiquitin proteasome mutants tir1-1 and axr1-12, which show enhanced resistance to 2,4-D compared with IAA for inhibition of root growth, were also found to have less disrupted actin filament networks after 2,4-D exposure. Consistently, a chemical inhibitor of the ubiquitin proteasome pathway mitigated the disrupting effects of 2,4-D on the organization of actin filaments. Roots of the double mutant aar1-1 tir1-1 also showed enhanced resistance to 2,4-D-induced inhibition of root growth and actin degradation compared with their respective parental lines. Collectively, these results suggest that the effects of 2,4-D on actin filament organization and root growth are mediated through synergistic interactions between SMAP1 and SCFTIR1 ubiquitin proteasome components.
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Affiliation(s)
- Maho Takahashi
- Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
| | - Kana Umetsu
- Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
| | - Yutaka Oono
- Department of Radiation-Applied Biology, Quantum Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology (QST), Takasaki, 370-1292, Japan
| | - Takumi Higaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8562, Japan
| | - Elison B Blancaflor
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA
| | - Abidur Rahman
- Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
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74
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Yang X, Dong G, Palaniappan K, Mi G, Baskin TI. Temperature-compensated cell production rate and elongation zone length in the root of Arabidopsis thaliana. PLANT, CELL & ENVIRONMENT 2017; 40:264-276. [PMID: 27813107 DOI: 10.1111/pce.12855] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/26/2016] [Accepted: 10/31/2016] [Indexed: 05/13/2023]
Abstract
To understand how root growth responds to temperature, we used kinematic analysis to quantify division and expansion parameters in the root of Arabidopsis thaliana. Plants were grown at temperatures from 15 to 30 °C, given continuously from germination. Over these temperatures, root length varies more than threefold in the wild type but by only twofold in a double mutant for phytochrome-interacting factor 4 and 5. For kinematics, the spatial profile of velocity was obtained with new software, Stripflow. We find that 30 °C truncates the elongation zone and curtails cell production, responses that probably reflect the elicitation of a common pathway for handling severe stresses. Curiously, rates of cell division at all temperatures are closely correlated with rates of radial expansion. Between 15 to 25 °C, root growth rate, maximal elemental elongation rate, and final cell length scale positively with temperature whereas the length of the meristem scales negatively. Non-linear temperature scaling characterizes meristem cell number, time to transit through either meristem or elongation zone, and average cell division rate. Surprisingly, the length of the elongation zone and the total rate of cell production are temperature invariant, constancies that have implications for our understanding of how the underlying cellular processes are integrated.
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Affiliation(s)
- Xiaoli Yang
- Biology Department, University of Massachusetts, Amherst, 01003, MA, USA
- College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China
| | - Gang Dong
- Biology Department, University of Massachusetts, Amherst, 01003, MA, USA
| | - K Palaniappan
- Computer Science Department, University of Missouri, Columbia, 65211, MO, USA
| | - Guohua Mi
- College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China
| | - Tobias I Baskin
- Biology Department, University of Massachusetts, Amherst, 01003, MA, USA
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75
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Geisler M, Bailly A, Ivanchenko M. Master and servant: Regulation of auxin transporters by FKBPs and cyclophilins. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 245:1-10. [PMID: 26940487 DOI: 10.1016/j.plantsci.2015.12.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/14/2015] [Accepted: 12/17/2015] [Indexed: 05/27/2023]
Abstract
Plant development and architecture are greatly influenced by the polar distribution of the essential hormone auxin. The directional influx and efflux of auxin from plant cells depends primarily on AUX1/LAX, PIN, and ABCB/PGP/MDR families of auxin transport proteins. The functional analysis of these proteins has progressed rapidly within the last decade thanks to the establishment of heterologous auxin transport systems. Heterologous co-expression allowed also for the testing of protein-protein interactions involved in the regulation of transporters and identified relationships with members of the FK506-Binding Protein (FKBP) and cyclophilin protein families, which are best known in non-plant systems as cellular receptors for the immunosuppressant drugs, FK506 and cyclosporin A, respectively. Current evidence that such interactions affect membrane trafficking, and potentially the activity of auxin transporters is reviewed. We also propose that FKBPs andcyclophilins might integrate the action of auxin transport inhibitors, such as NPA, on members of the ABCB and PIN family, respectively. Finally, we outline open questions that might be useful for further elucidation of the role of immunophilins as regulators (servants) of auxin transporters (masters).
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Affiliation(s)
- Markus Geisler
- University of Fribourg, Department of Biology-Plant Biology, CH-1700 Fribourg, Switzerland.
| | - Aurélien Bailly
- University of Zurich, Institute of Plant Biology, CH-8008 Zurich, Switzerland
| | - Maria Ivanchenko
- Oregon State University, Department of Botany and Plant Pathology, 2082 Cordley Hall, Corvallis, OR 97331, USA.
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76
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Eckstein A, Krzeszowiec W, Waligórski P, Gabryś H. Auxin and chloroplast movements. PHYSIOLOGIA PLANTARUM 2016; 156:351-366. [PMID: 26467664 DOI: 10.1111/ppl.12396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 09/14/2015] [Indexed: 06/05/2023]
Abstract
Auxin is involved in a wide spectrum of physiological processes in plants, including responses controlled by the blue light photoreceptors phototropins: phototropic bending and stomatal movement. However, the role of auxin in phototropin-mediated chloroplast movements has never been studied. To address this question we searched for potential interactions between auxin and the chloroplast movement signaling pathway using different experimental approaches and two model plants, Arabidopsis thaliana and Nicotiana tabacum. We observed that the disturbance of auxin homeostasis by shoot decapitation caused a decrease in chloroplast movement parameters, which could be rescued by exogenous auxin application. In several cases, the impairment of polar auxin transport, by chemical inhibitors or in auxin carrier mutants, had a similar negative effect on chloroplast movements. This inhibition was not correlated with changes in auxin levels. Chloroplast relocations were also affected by the antiauxin p-chlorophenoxyisobutyric acid and mutations in genes encoding some of the elements of the SCF(TIR1)-Aux/IAA auxin receptor complex. The observed changes in chloroplast movement parameters are not prominent, which points to a modulatory role of auxin in this process. Taken together, the obtained results suggest that auxin acts indirectly to regulate chloroplast movements, presumably by regulating gene expression via the SCF(TIR1)-Aux/IAA-ARF pathway. Auxin does not seem to be involved in controlling the expression of phototropins.
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Affiliation(s)
- Aleksandra Eckstein
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Weronika Krzeszowiec
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Piotr Waligórski
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków, Poland
| | - Halina Gabryś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
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77
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Rosero A, Oulehlová D, Stillerová L, Schiebertová P, Grunt M, Žárský V, Cvrčková F. Arabidopsis FH1 Formin Affects Cotyledon Pavement Cell Shape by Modulating Cytoskeleton Dynamics. PLANT & CELL PHYSIOLOGY 2016; 57:488-504. [PMID: 26738547 DOI: 10.1093/pcp/pcv209] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 12/24/2015] [Indexed: 05/03/2023]
Abstract
Plant cell morphogenesis involves concerted rearrangements of microtubules and actin microfilaments. We previously reported that FH1, the main Arabidopsis thaliana housekeeping Class I membrane-anchored formin, contributes to actin dynamics and microtubule stability in rhizodermis cells. Here we examine the effects of mutations affecting FH1 (At3g25500) on cell morphogenesis and above-ground organ development in seedlings, as well as on cytoskeletal organization and dynamics, using a combination of confocal and variable angle epifluorescence microscopy with a pharmacological approach. Homozygous fh1 mutants exhibited cotyledon epinasty and had larger cotyledon pavement cells with more pronounced lobes than the wild type. The pavement cell shape alterations were enhanced by expression of the fluorescent microtubule marker GFP-microtubule-associated protein 4 (MAP4). Mutant cotyledon pavement cells exhibited reduced density and increased stability of microfilament bundles, as well as enhanced dynamics of microtubules. Analogous results were also obtained upon treatments with the formin inhibitor SMIFH2 (small molecule inhibitor of formin homology 2 domains). Pavement cell shape in wild-type (wt) and fh1 plants in some situations exhibited a differential response towards anti-cytoskeletal drugs, especially the microtubule disruptor oryzalin. Our observations indicate that FH1 participates in the control of microtubule dynamics, possibly via its effects on actin, subsequently influencing cell morphogenesis and macroscopic organ development.
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Affiliation(s)
- Amparo Rosero
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Colombian Institute for Agricultural Research-CORPOICA-Turipana, Km 13 via Monteria, Cereté, Cordoba, Colombia Department of Cell Biology, Faculty of Science, Palacký University Olomouc, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 586/11, CZ 783 71 Olomouc-Holice, Czech Republic
| | - Denisa Oulehlová
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ 160 00 Prague 6, Czech Republic
| | - Lenka Stillerová
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
| | - Petra Schiebertová
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
| | - Michal Grunt
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ 160 00 Prague 6, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
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78
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Scheuring D, Löfke C, Krüger F, Kittelmann M, Eisa A, Hughes L, Smith RS, Hawes C, Schumacher K, Kleine-Vehn J. Actin-dependent vacuolar occupancy of the cell determines auxin-induced growth repression. Proc Natl Acad Sci U S A 2016; 113:452-7. [PMID: 26715743 PMCID: PMC4720293 DOI: 10.1073/pnas.1517445113] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The cytoskeleton is an early attribute of cellular life, and its main components are composed of conserved proteins. The actin cytoskeleton has a direct impact on the control of cell size in animal cells, but its mechanistic contribution to cellular growth in plants remains largely elusive. Here, we reveal a role of actin in regulating cell size in plants. The actin cytoskeleton shows proximity to vacuoles, and the phytohormone auxin not only controls the organization of actin filaments but also impacts vacuolar morphogenesis in an actin-dependent manner. Pharmacological and genetic interference with the actin-myosin system abolishes the effect of auxin on vacuoles and thus disrupts its negative influence on cellular growth. SEM-based 3D nanometer-resolution imaging of the vacuoles revealed that auxin controls the constriction and luminal size of the vacuole. We show that this actin-dependent mechanism controls the relative vacuolar occupancy of the cell, thus suggesting an unanticipated mechanism for cytosol homeostasis during cellular growth.
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Affiliation(s)
- David Scheuring
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Christian Löfke
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Falco Krüger
- Center for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Maike Kittelmann
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Ahmed Eisa
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Louise Hughes
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Richard S Smith
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Chris Hawes
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Karin Schumacher
- Center for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Jürgen Kleine-Vehn
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, 1190 Vienna, Austria;
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79
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Wang Q, An B, Wei Y, Reiter RJ, Shi H, Luo H, He C. Melatonin Regulates Root Meristem by Repressing Auxin Synthesis and Polar Auxin Transport in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2016. [PMID: 28018411 DOI: 10.3389/fpls.201601882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine) plays important roles in regulating both biotic and abiotic stress tolerance, biological rhythms, plant growth and development. Sharing the same substrate (tryptophan) for the biosynthesis, melatonin and auxin also have similar effects in plant development. However, the specific function of melatonin in modulating plant root growth and the relationship between melatonin and auxin as well as underlying mechanisms are still unclear. In this study, we found high concentration of melatonin remarkably inhibited root growth in Arabidopsis by reducing root meristem size. Further studies showed that melatonin negatively regulated auxin biosynthesis, the expression of PINFORMED (PIN) proteins as well as auxin response in Arabidopsis. Moreover, the root growth of the triple mutant pin1pin3pin7 was more tolerant than that of wild-type in response to melatonin treatment, suggesting the essential role of PIN1/3/7 in melatonin-mediated root growth. Combination treatment of melatonin and 5-Triiodobenzoic acid (TIBA) did not enhance melatonin-mediated reduction of root meristem size, indicating that polar auxin transport (PAT) may be necessary for the regulation of root meristem size by melatonin treatment. Taken together, this study indicates that melatonin regulates root growth in Arabidopsis, through auxin synthesis and polar auxin transport, at least partially.
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Affiliation(s)
- Qiannan Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Bang An
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Yunxie Wei
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Russel J Reiter
- Department of Cell Systems and Anatomy, The University of Texas Health Science Center San Antonio, TX, USA
| | - Haitao Shi
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Hongli Luo
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
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80
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Kučerová D, Kollárová K, Vatehová Z, Lišková D. Interaction of galactoglucomannan oligosaccharides with auxin involves changes in flavonoid accumulation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 98:155-161. [PMID: 26691060 DOI: 10.1016/j.plaphy.2015.11.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 11/24/2015] [Accepted: 11/27/2015] [Indexed: 06/05/2023]
Abstract
Galactoglucomannan oligosaccharides (GGMOs) are signalling molecules originating from plant cell walls influencing plant growth and defence reactions. The present study focused on their interaction with exogenous IAA (indole-3-acetic acid). GGMOs acted as auxin antagonists and diminished the effect of IAA on Arabidopsis primary root growth. Their effect is associated with meristem enlargement and prolongation of the elongation zone. Reduction of the elongation zone was a consequence of the IAA action, but IAA did not affect the size of the meristem. In the absence of auxin, GGMOs stimulated root growth, meristem enlargement and elongation zone prolongation. It is assumed that the effect of GGMOs in the absence of exogenous auxin resulted from their interaction with the endogenous form. In the presence of auxin transport inhibitor GGMOs did not affect root growth. It is known that flavonoids are auxin transport modulators but this is the first study suggesting the role of flavonoids in GGMOs' signalling. The accumulation of flavonoids in the meristem and elongation zone decreased in GGMOs' treatments in comparison with the control. These oligosaccharides also diminished the effect of IAA on the flavonoids' elevation. The fact that GGMOs decreased the accumulation of flavonoids, known to be modulators of auxin transport, and the loss of GGMOs' activity in the presence of the auxin transport inhibitor indicates that the root growth stimulation caused by GGMOs could be related to changes in auxin transport, possibly mediated by flavonoids.
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Affiliation(s)
- Danica Kučerová
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava 845 38, Slovakia
| | - Karin Kollárová
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava 845 38, Slovakia.
| | - Zuzana Vatehová
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava 845 38, Slovakia
| | - Desana Lišková
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava 845 38, Slovakia
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81
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de Vries J, Fischer AM, Roettger M, Rommel S, Schluepmann H, Bräutigam A, Carlsbecker A, Gould SB. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots. THE NEW PHYTOLOGIST 2016; 209:705-20. [PMID: 26358624 PMCID: PMC5049668 DOI: 10.1111/nph.13630] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 08/04/2015] [Indexed: 05/10/2023]
Abstract
The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises the questions of how auxin and cytokinin govern fern root system architecture and whether this can tell us something about the origin of that root. Using Azolla filiculoides, we characterized the influence of IAA and zeatin on adventitious fern root meristems and vasculature by Nomarski microscopy. Simultaneously, RNAseq analyses, yielding 36,091 contigs, were used to uncover how the phytohormones affect root tip gene expression. We show that auxin restricts Azolla root meristem development, while cytokinin promotes it; it is the opposite effect of what is observed in Arabidopsis. Global gene expression profiling uncovered 145 genes significantly regulated by cytokinin or auxin, including cell wall modulators, cell division regulators and lateral root formation coordinators. Our data illuminate both evolution and development of fern roots. Promotion of meristem size through cytokinin supports the idea that root meristems of euphyllophytes evolved from shoot meristems. The foundation of these roots was laid in a postembryonically branching shoot system.
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Affiliation(s)
- Jan de Vries
- Molecular EvolutionHeinrich‐Heine‐University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Angela Melanie Fischer
- Molecular EvolutionHeinrich‐Heine‐University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Mayo Roettger
- Molecular EvolutionHeinrich‐Heine‐University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Sophie Rommel
- Population GeneticsHeinrich‐Heine‐University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Henriette Schluepmann
- Molecular Plant PhysiologyUtrecht UniversityPadualaan 83584CH Utrechtthe Netherlands
| | - Andrea Bräutigam
- Plant BiochemistryHeinrich‐Heine‐University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Annelie Carlsbecker
- Department of Organismal Biology, Physiological BotanyUppsala BioCenterLinnean Centre for Plant BiologyUppsala UniversityUlls väg 24ESE‐756 51UppsalaSweden
| | - Sven Bernhard Gould
- Molecular EvolutionHeinrich‐Heine‐University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
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82
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Poupin MJ, Greve M, Carmona V, Pinedo I. A Complex Molecular Interplay of Auxin and Ethylene Signaling Pathways Is Involved in Arabidopsis Growth Promotion by Burkholderia phytofirmans PsJN. FRONTIERS IN PLANT SCIENCE 2016; 7:492. [PMID: 27148317 PMCID: PMC4828629 DOI: 10.3389/fpls.2016.00492] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/28/2016] [Indexed: 05/05/2023]
Abstract
Modulation of phytohormones homeostasis is one of the proposed mechanisms to explain plant growth promotion induced by beneficial rhizobacteria (PGPR). However, there is still limited knowledge about the molecular signals and pathways underlying these beneficial interactions. Even less is known concerning the interplay between phytohormones in plants inoculated with PGPR. Auxin and ethylene are crucial hormones in the control of plant growth and development, and recent studies report an important and complex crosstalk between them in the regulation of different plant developmental processes. The objective of this work was to study the role of both hormones in the growth promotion of Arabidopsis thaliana plants induced by the well-known PGPR Burkholderia phytofirmans PsJN. For this, the spatiotemporal expression patterns of several genes related to auxin biosynthesis, perception and response and ethylene biosynthesis were studied, finding that most of these genes showed specific transcriptional regulations after inoculation in roots and shoots. PsJN-growth promotion was not observed in Arabidopsis mutants with an impaired ethylene (ein2-1) or auxin (axr1-5) signaling. Even, PsJN did not promote growth in an ethylene overproducer (eto2), indicating that a fine regulation of both hormones signaling and homeostasis is necessary to induce growth of the aerial and root tissues. Auxin polar transport is also involved in growth promotion, since PsJN did not promote primary root growth in the pin2 mutant or under chemical inhibition of transport in wild type plants. Finally, a key role for ethylene biosynthesis was found in the PsJN-mediated increase in root hair number. These results not only give new insights of PGPR regulation of plant growth but also are also useful to understand key aspects of Arabidopsis growth control.
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Affiliation(s)
- María J. Poupin
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center for Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
- *Correspondence: María J. Poupin,
| | - Macarena Greve
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center for Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
| | - Vicente Carmona
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center for Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
| | - Ignacio Pinedo
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center for Applied Ecology and SustainabilitySantiago, Chile
- Millennium Nucleus Center for Plant Systems and Synthetic BiologySantiago, Chile
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83
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Wang Q, An B, Wei Y, Reiter RJ, Shi H, Luo H, He C. Melatonin Regulates Root Meristem by Repressing Auxin Synthesis and Polar Auxin Transport in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2016; 7:1882. [PMID: 28018411 PMCID: PMC5156734 DOI: 10.3389/fpls.2016.01882] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 11/29/2016] [Indexed: 05/18/2023]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine) plays important roles in regulating both biotic and abiotic stress tolerance, biological rhythms, plant growth and development. Sharing the same substrate (tryptophan) for the biosynthesis, melatonin and auxin also have similar effects in plant development. However, the specific function of melatonin in modulating plant root growth and the relationship between melatonin and auxin as well as underlying mechanisms are still unclear. In this study, we found high concentration of melatonin remarkably inhibited root growth in Arabidopsis by reducing root meristem size. Further studies showed that melatonin negatively regulated auxin biosynthesis, the expression of PINFORMED (PIN) proteins as well as auxin response in Arabidopsis. Moreover, the root growth of the triple mutant pin1pin3pin7 was more tolerant than that of wild-type in response to melatonin treatment, suggesting the essential role of PIN1/3/7 in melatonin-mediated root growth. Combination treatment of melatonin and 5-Triiodobenzoic acid (TIBA) did not enhance melatonin-mediated reduction of root meristem size, indicating that polar auxin transport (PAT) may be necessary for the regulation of root meristem size by melatonin treatment. Taken together, this study indicates that melatonin regulates root growth in Arabidopsis, through auxin synthesis and polar auxin transport, at least partially.
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Affiliation(s)
- Qiannan Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Bang An
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Yunxie Wei
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Russel J Reiter
- Department of Cell Systems and Anatomy, The University of Texas Health Science Center San Antonio, TX, USA
| | - Haitao Shi
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Hongli Luo
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University Haikou, China
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84
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Slovak R, Ogura T, Satbhai SB, Ristova D, Busch W. Genetic control of root growth: from genes to networks. ANNALS OF BOTANY 2016; 117:9-24. [PMID: 26558398 PMCID: PMC4701154 DOI: 10.1093/aob/mcv160] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/28/2015] [Indexed: 05/08/2023]
Abstract
BACKGROUND Roots are essential organs for higher plants. They provide the plant with nutrients and water, anchor the plant in the soil, and can serve as energy storage organs. One remarkable feature of roots is that they are able to adjust their growth to changing environments. This adjustment is possible through mechanisms that modulate a diverse set of root traits such as growth rate, diameter, growth direction and lateral root formation. The basis of these traits and their modulation are at the cellular level, where a multitude of genes and gene networks precisely regulate development in time and space and tune it to environmental conditions. SCOPE This review first describes the root system and then presents fundamental work that has shed light on the basic regulatory principles of root growth and development. It then considers emerging complexities and how they have been addressed using systems-biology approaches, and then describes and argues for a systems-genetics approach. For reasons of simplicity and conciseness, this review is mostly limited to work from the model plant Arabidopsis thaliana, in which much of the research in root growth regulation at the molecular level has been conducted. CONCLUSIONS While forward genetic approaches have identified key regulators and genetic pathways, systems-biology approaches have been successful in shedding light on complex biological processes, for instance molecular mechanisms involving the quantitative interaction of several molecular components, or the interaction of large numbers of genes. However, there are significant limitations in many of these methods for capturing dynamic processes, as well as relating these processes to genotypic and phenotypic variation. The emerging field of systems genetics promises to overcome some of these limitations by linking genotypes to complex phenotypic and molecular data using approaches from different fields, such as genetics, genomics, systems biology and phenomics.
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Affiliation(s)
- Radka Slovak
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Takehiko Ogura
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Santosh B Satbhai
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Daniela Ristova
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Wolfgang Busch
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
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85
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Hu Y, Na X, Li J, Yang L, You J, Liang X, Wang J, Peng L, Bi Y. Narciclasine, a potential allelochemical, affects subcellular trafficking of auxin transporter proteins and actin cytoskeleton dynamics in Arabidopsis roots. PLANTA 2015; 242:1349-1360. [PMID: 26232920 DOI: 10.1007/s00425-015-2373-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 07/13/2015] [Indexed: 06/04/2023]
Abstract
The present study documented the action of a potential allelochemical, narciclasine, on auxin transport in Arabidopsis by mainly affecting subcellular trafficking of PIN and AUX1 proteins and through interfering actin cytoskeletal organization. Narciclasine (NCS), an Amaryllidaceae alkaloid isolated from Narcissus tazetta bulbs, has potential allelopathic activity and affects auxin transport. However, little is known about the cellular mechanism of this inhibitory effect of NCS on auxin transport. The present study characterizes the effects of NCS at the cellular level using transgenic Arabidopsis plants harboring the promoters of PIN, in combination with PIN-GFP proteins or AUX1-YFP fusions. NCS treatment caused significant reduction in the abundance of PIN and AUX1 proteins at the plasma membrane (PM). Analysis of the subcellular distribution of PIN and AUX1 proteins in roots revealed that NCS induced the intracellular accumulation of auxin transporters, including PIN2, PIN3, PIN4, PIN7 and AUX1. However, other PM proteins, such as PIP2, BRI1, and low temperature inducible protein 6b (LTI6b), were insensitive to NCS treatment. NCS-induced PIN2 compartments were further defined using endocytic tracer FM 4-64 labeled early endosomes and suggested that this compound affects the endocytosis trafficking of PIN proteins. Furthermore, pharmacological analysis indicated that the brefeldin A (BFA)-insensitive pathway is employed in the cellular effects of NCS on PIN2 trafficking. Although NCS did not alter actin dynamics in vitro, it resulted in the depolymerization of the actin cytoskeleton in vivo. This disruption of actin filaments by NCS subsequently influences the actin-based vesicle motility. Hence, the elucidation of the specific role of NCS is useful for further understanding the mechanisms of allelopathy at the phytohormone levels.
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Affiliation(s)
- Yanfeng Hu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150000, People's Republic of China
| | - Xiaofan Na
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Jiaolong Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Lijing Yang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Jia You
- School of Life Science, Northwest Normal University, Lanzhou, 730070, People's Republic of China
| | - Xiaolei Liang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Jianfeng Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Liang Peng
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Yurong Bi
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
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86
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Zhu J, Geisler M. Keeping it all together: auxin-actin crosstalk in plant development. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:4983-98. [PMID: 26085676 DOI: 10.1093/jxb/erv308] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Polar auxin transport and the action of the actin cytoskeleton are tightly interconnected, which is documented by the finding that auxin transporters reach their final destination by active movement of secretory vesicles along F-actin tracks. Moreover, auxin transporter polarity and flexibility is thought to depend on transporter cycling that requires endocytosis and exocytosis of vesicles. In this context, we have reviewed the current literature on an involvement of the actin cytoskeleton in polar auxin transport and identify known similarities and differences in its structure, function and dynamics in comparison to non-plant organisms. By describing how auxin modulates actin expression and actin organization and how actin and its stability affects auxin-transporter endocytosis and recycling, we discuss the current knowledge on regulatory auxin-actin feedback loops. We focus on known effects of auxin and of auxin transport inhibitors on the stability and organization of actin and examine the functionality of auxin and/or auxin transport inhibitor-binding proteins with respect to their suitability to integrate auxin/auxin transport inhibitor action. Finally, we indicate current difficulties in the interpretation of organ, time and concentration-dependent auxin/auxin transport inhibitor treatments and formulate simple future experimental guidelines.
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Affiliation(s)
- Jinsheng Zhu
- University of Fribourg, Department of Biology-Plant Biology, CH-1700 Fribourg, Switzerland
| | - Markus Geisler
- University of Fribourg, Department of Biology-Plant Biology, CH-1700 Fribourg, Switzerland
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87
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Wang J, Zhang Y, Li Y, Wang X, Nan W, Hu Y, Zhang H, Zhao C, Wang F, Li P, Shi H, Bi Y. Endophytic microbes Bacillus sp. LZR216-regulated root development is dependent on polar auxin transport in Arabidopsis seedlings. PLANT CELL REPORTS 2015; 34:1075-1087. [PMID: 25700982 DOI: 10.1007/s00299-015-1766-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 01/14/2015] [Accepted: 02/10/2015] [Indexed: 06/04/2023]
Abstract
Endophytic microbes Bacillus sp. LZR216 isolated from Arabidopsis root promoted Arabidopsis seedlings growth. It may be achieved by promoting the lateral root growth and inhibiting the primary root elongation. Plant roots are colonized by an immense number of microbes, including epiphytic and endophytic microbes. It was found that they have the ability to promote plant growth and protect roots from biotic and abiotic stresses. But little is known about the mechanism of the endophytic microbes-regulated root development. We isolated and identified a Bacillus sp., named as LZR216, of endophytic bacteria from Arabidopsis root. By employing a sterile experimental system, we found that LZR216 promoted the Arabidopsis seedlings growth, which may be achieved by promoting the lateral root growth and inhibiting the primary root elongation. By testing the cell type-specific developmental markers, we demonstrated that Bacillus sp. LZR216 increases the DR5::GUS and DR5::GFP expression but decreases the CYCB1;1::GUS expression in Arabidopsis root tips. Further studies indicated that LZR216 is able to inhibit the meristematic length and decrease the cell division capability but has little effect on the quiescent center function of the root meristem. Subsequently, it was also shown that LZR216 has no significant effects on the primary root length of the pin2 and aux1-7 mutants. Furthermore, LZR216 down-regulates the levels of PIN1-GFP, PIN2-GFP, PIN3-GFP, and AUX1-YFP. In addition, the wild-type Arabidopsis seedlings in the present of 1 or 5 µM NPA (an auxin transport inhibitor) were insensitive to LZR216-inhibited primary root elongation. Collectively, LZR216 regulates the development of root system architecture depending on polar auxin transport. This study shows a new insight on the ability of beneficial endophytic bacteria in regulating postembryonic root development.
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Affiliation(s)
- Jianfeng Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
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88
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Actin as deathly switch? How auxin can suppress cell-death related defence. PLoS One 2015; 10:e0125498. [PMID: 25933033 PMCID: PMC4416736 DOI: 10.1371/journal.pone.0125498] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 03/17/2015] [Indexed: 11/19/2022] Open
Abstract
Plant innate immunity is composed of two layers--a basal immunity, and a specific effector-triggered immunity, which is often accompanied by hypersensitive cell death. Initiation of cell death depends on a complex network of signalling pathways. The phytohormone auxin as central regulator of plant growth and development represents an important component for the modulation of plant defence. In our previous work, we showed that cell death is heralded by detachment of actin from the membrane. Both, actin response and cell death, are triggered by the bacterial elicitor harpin in grapevine cells. In this study we investigated, whether harpin-triggered actin bundling is necessary for harpin-triggered cell death. Since actin organisation is dependent upon auxin, we used different auxins to suppress actin bundling. Extracellular alkalinisation and transcription of defence genes as the basal immunity were examined as well as cell death. Furthermore, organisation of actin was observed in response to pharmacological manipulation of reactive oxygen species and phospholipase D. We find that induction of defence genes is independent of auxin. However, auxin can suppress harpin-induced cell death and also counteract actin bundling. We integrate our findings into a model, where harpin interferes with an auxin dependent pathway that sustains dynamic cortical actin through the activity of phospholipase D. The antagonism between growth and defence is explained by mutual competition for signal molecules such as superoxide and phosphatidic acid. Perturbations of the auxin-actin pathway might be used to detect disturbed integrity of the plasma membrane and channel defence signalling towards programmed cell death.
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89
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Chaiwanon J, Wang ZY. Spatiotemporal brassinosteroid signaling and antagonism with auxin pattern stem cell dynamics in Arabidopsis roots. Curr Biol 2015; 25:1031-42. [PMID: 25866388 DOI: 10.1016/j.cub.2015.02.046] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 02/02/2015] [Accepted: 02/18/2015] [Indexed: 01/04/2023]
Abstract
The spatiotemporal balance between stem cell maintenance, proliferation, and differentiation determines the rate of root growth and is controlled by hormones, including auxin and brassinosteroid (BR). However, the spatial actions of BR and its interactions with auxin remain unclear in roots. Here, we show that oppositely patterned and antagonistic actions of BR and auxin maintain the stem cell balance and optimal root growth. We discover a pattern of low levels of nuclear-localized BR-activated transcription factor BZR1 in the stem cell niche and high BZR1 levels in the transition-elongation zone. This BZR1 pattern requires local BR catabolism and auxin synthesis, as well as BR signaling. Cell-type-specific expression of a constitutively active form of BZR1 confirms that the high and low levels of BZR1 are required for the normal cell behaviors in the elongation zone and quiescent center (QC), respectively. Comparison between BR-responsive, BZR1-targeted, auxin-responsive, and developmental zone-specific transcriptomes indicates that BZR1 mostly activates its target genes expressed in the transition-elongation zone, but represses genes in the QC and surrounding stem cells, and that BR and auxin have overall opposite effects on gene expression. Genetic and physiological interactions support that a balance between the antagonistic actions of BR and auxin is required for optimal root growth. These results demonstrate that the level and output specificity of BR signaling are spatially patterned and that, in contrast to their synergism in shoots, BR and auxin interact antagonistically in roots to control the spatiotemporal balance of stem cell dynamics required for optimal root growth.
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Affiliation(s)
- Juthamas Chaiwanon
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Zhi-Yong Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
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90
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Zelinová V, Alemayehu A, Bočová B, Huttová J, Tamás L. Cadmium-induced reactive oxygen species generation, changes in morphogenic responses and activity of some enzymes in barley root tip are regulated by auxin. Biologia (Bratisl) 2015. [DOI: 10.1515/biolog-2015-0035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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91
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Jia H, Hu Y, Fan T, Li J. Hydrogen sulfide modulates actin-dependent auxin transport via regulating ABPs results in changing of root development in Arabidopsis. Sci Rep 2015; 5:8251. [PMID: 25652660 PMCID: PMC4317700 DOI: 10.1038/srep08251] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/12/2015] [Indexed: 01/22/2023] Open
Abstract
Hydrogen sulfide (H2S) signaling has been considered a key regulator of plant developmental processes and defenses. In this study, we demonstrate that high levels of H2S inhibit auxin transport and lead to alterations in root system development. H2S inhibits auxin transport by altering the polar subcellular distribution of PIN proteins. The vesicle trafficking and distribution of the PIN proteins are an actin-dependent process. H2S changes the expression of several actin-binding proteins (ABPs) and decreases the occupancy percentage of F-actin bundles in the Arabidopsis roots. We observed the effects of H2S on F-actin in T-DNA insertion mutants of cpa, cpb and prf3, indicating that the effects of H2S on F-actin are partially removed in the mutant plants. Thus, these data imply that the ABPs act as downstream effectors of the H2S signal and thereby regulate the assembly and depolymerization of F-actin in root cells. Taken together, our data suggest that the existence of a tightly regulated intertwined signaling network between auxin, H2S and actin that controls root system development. In the proposed process, H2S plays an important role in modulating auxin transport by an actin-dependent method, which results in alterations in root development in Arabidopsis.
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Affiliation(s)
- Honglei Jia
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yanfeng Hu
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Nangang District, Harbin 150000, China
| | - Tingting Fan
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
| | - Jisheng Li
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
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92
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González-Fontes A, Herrera-Rodríguez MB, Martín-Rejano EM, Navarro-Gochicoa MT, Rexach J, Camacho-Cristóbal JJ. Root Responses to Boron Deficiency Mediated by Ethylene. FRONTIERS IN PLANT SCIENCE 2015; 6:1103. [PMID: 26779202 PMCID: PMC4705265 DOI: 10.3389/fpls.2015.01103] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/22/2015] [Indexed: 05/02/2023]
Abstract
Low boron (B) supply alters the architecture of the root system in Arabidopsis thaliana seedlings, leading to a reduction in the primary root growth and an increase in the length and number of root hairs. At short-term (hours), B deficiency causes a decrease in the cell elongation of the primary root, resulting in a lower growth. Experimental approaches using ethylene insensitive Arabidopsis mutants, inhibitors of ethylene response, and GUS reporter lines suggest that ethylene is involved in these responses of the primary root to B deficiency. Furthermore, it has been shown that auxin participates in the inhibition of cell elongation under short-term B deprivation. These results support that an interaction between ethylene and auxin plays an important role in controlling the primary root elongation, in which a number of genes related to the synthesis, transport, and signaling of both phytohormones could modulate this effect. Evidence for a root cross-talk among both hormones and other possible intermediates (abscisic acid, calcium sensors, and reactive oxygen species) in response to B deficiency is provided and discussed.
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93
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Cole RA, McInally SA, Fowler JE. Developmentally distinct activities of the exocyst enable rapid cell elongation and determine meristem size during primary root growth in Arabidopsis. BMC PLANT BIOLOGY 2014; 14:386. [PMID: 25551204 PMCID: PMC4302519 DOI: 10.1186/s12870-014-0386-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/15/2014] [Indexed: 05/20/2023]
Abstract
BACKGROUND Exocytosis is integral to root growth: trafficking components of systems that control growth (e.g., PIN auxin transport proteins) to the plasma membrane, and secreting materials that expand the cell wall to the apoplast. Spatiotemporal regulation of exocytosis in eukaryotes often involves the exocyst, an octameric complex that tethers selected secretory vesicles to specific sites on the plasma membrane and facilitates their exocytosis. We evaluated Arabidopsis lines with mutations in four exocyst components (SEC5, SEC8, EXO70A1 and EXO84B) to explore exocyst function in primary root growth. RESULTS The mutants have root growth rates that are 82% to 11% of wild-type. Even in lines with the most severe defects, the organization of the quiescent center and tissue layers at the root tips appears similar to wild-type, although meristematic, transition, and elongation zones are shorter. Reduced cell production rates in the mutants are due to the shorter meristems, but not to lengthened cell cycles. Additionally, mutants demonstrate reduced anisotropic cell expansion in the elongation zone, but not the meristematic zone, resulting in shorter mature cells that are similar in shape to wild-type. As expected, hypersensitivity to brefeldin A links the mutant root growth defect to altered vesicular trafficking. Several experimental approaches (e.g., dose-response measurements, localization of signaling components) failed to identify aberrant auxin or brassinosteroid signaling as a primary driver for reduced root growth in exocyst mutants. CONCLUSIONS The exocyst participates in two spatially distinct developmental processes, apparently by mechanisms not directly linked to auxin or brassinosteroid signaling pathways, to help establish root meristem size, and to facilitate rapid cell expansion in the elongation zone.
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Affiliation(s)
- Rex A Cole
- Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, 97331 OR USA
| | - Samantha A McInally
- Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, 97331 OR USA
| | - John E Fowler
- Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, 97331 OR USA
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94
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Iglesias MJ, Terrile MC, Windels D, Lombardo MC, Bartoli CG, Vazquez F, Estelle M, Casalongué CA. MiR393 regulation of auxin signaling and redox-related components during acclimation to salinity in Arabidopsis. PLoS One 2014; 9:e107678. [PMID: 25222737 PMCID: PMC4164656 DOI: 10.1371/journal.pone.0107678] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 08/15/2014] [Indexed: 02/08/2023] Open
Abstract
One of the most striking aspects of plant plasticity is the modulation of development in response to environmental changes. Plant growth and development largely depend on the phytohormone auxin that exerts its function through a partially redundant family of F-box receptors, the TIR1-AFBs. We have previously reported that the Arabidopsis double mutant tir1 afb2 is more tolerant to salt stress than wild-type plants and we hypothesized that down-regulation of auxin signaling might be part of Arabidopsis acclimation to salinity. In this work, we show that NaCl-mediated salt stress induces miR393 expression by enhancing the transcription of AtMIR393A and leads to a concomitant reduction in the levels of the TIR1 and AFB2 receptors. Consequently, NaCl triggers stabilization of Aux/IAA repressors leading to down-regulation of auxin signaling. Further, we report that miR393 is likely involved in repression of lateral root (LR) initiation, emergence and elongation during salinity, since the mir393ab mutant shows reduced inhibition of emergent and mature LR number and length upon NaCl-treatment. Additionally, mir393ab mutant plants have increased levels of reactive oxygen species (ROS) in LRs, and reduced ascorbate peroxidase (APX) enzymatic activity compared with wild-type plants during salinity. Thus, miR393 regulation of the TIR1 and AFB2 receptors could be a critical checkpoint between auxin signaling and specfic redox-associated components in order to coordinate tissue and time-specific growth responses and tolerance during acclimation to salinity in Arabidopsis.
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Affiliation(s)
- María José Iglesias
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - María Cecilia Terrile
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - David Windels
- Instituto de Fisiología Vegetal, Facultad de Ciencias Naturales, Universidad Nacional de La Plata-CCT La Plata CONICET, La Plata, Argentina
| | - María Cristina Lombardo
- Departamento de Biología e Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Carlos Guillermo Bartoli
- Instituto de Fisiología Vegetal, Facultad de Ciencias Naturales, Universidad Nacional de La Plata-CCT La Plata CONICET, La Plata, Argentina
| | - Franck Vazquez
- Botanical Institute of the University of Basel, Zürich-Basel Plant Science Center, Part of the Swiss Plant Science Web, Department of Environmental Sciences, Basel, Switzerland
| | - Mark Estelle
- Section of Cell and Developmental Biology, University of California San Diego, San Diego, California, United States of America
- Howard Hughes Medical Institute, University of California San Diego, San Diego, California, United States of America
| | - Claudia Anahí Casalongué
- Instituto de Investigaciones Biológicas, UE-CONICET-UNMDP, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
- * E-mail:
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95
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Rodríguez-Serrano M, Pazmiño DM, Sparkes I, Rochetti A, Hawes C, Romero-Puertas MC, Sandalio LM. 2,4-Dichlorophenoxyacetic acid promotes S-nitrosylation and oxidation of actin affecting cytoskeleton and peroxisomal dynamics. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:4783-93. [PMID: 24913628 PMCID: PMC4144765 DOI: 10.1093/jxb/eru237] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) is a synthetic auxin used as a herbicide to control weeds in agriculture. A high concentration of 2,4-D promotes leaf epinasty and cell death. In this work, the molecular mechanisms involved in the toxicity of this herbicide are studied by analysing in Arabidopsis plants the accumulation of reactive oxygen species (ROS) and nitric oxide (NO), and their effect on cytoskeleton structure and peroxisome dynamics. 2,4-D (23 mM) promotes leaf epinasty, whereas this process was prevented by EDTA, which can reduce ·OH accumulation. The analysis of ROS accumulation by confocal microscopy showed a 2,4-D-dependent increase in both H2O2 and O2·(-), whereas total NO was not affected by the treatment. The herbicide promotes disturbances on the actin cytoskeleton structure as a result of post-translational modification of actin by oxidation and S-nitrosylation, which could disturb actin polymerization, as suggested by the reduction of the F-actin/G-actin ratio. These effects were reduced by EDTA, and the reduction of ROS production in Arabidopsis mutants deficient in xanthine dehydrogenase (Atxdh) gave rise to a reduction in actin oxidation. Also, 2,4-D alters the dynamics of the peroxisome, slowing the speed and shortening the distances by which these organelles are displaced. It is concluded that 2,4-D promotes oxidative and nitrosative stress, causing disturbances in the actin cytoskeleton, thereby affecting the dynamics of peroxisomes and some other organelles such as the mitochondria, with xanthine dehydrogenase being involved in ROS production under these conditions. These structural changes in turn appear to be responsible for the leaf epinasty.
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Affiliation(s)
- M Rodríguez-Serrano
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado 419, 18080 Granada, Spain
| | - D M Pazmiño
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado 419, 18080 Granada, Spain
| | - I Sparkes
- School of Biological & Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - A Rochetti
- School of Biological & Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - C Hawes
- School of Biological & Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - M C Romero-Puertas
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado 419, 18080 Granada, Spain
| | - L M Sandalio
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado 419, 18080 Granada, Spain
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96
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Adamakis IDS, Panteris E, Eleftheriou EP. Tungsten disrupts root growth in Arabidopsis thaliana by PIN targeting. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:1174-87. [PMID: 24973590 DOI: 10.1016/j.jplph.2014.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 03/23/2014] [Accepted: 04/25/2014] [Indexed: 05/19/2023]
Abstract
Tungsten is a heavy metal with increasing concern over its environmental impact. In plants it is extensively used to deplete nitric oxide by inhibiting nitrate reductase, but its presumed toxicity as a heavy metal has been less explored. Accordingly, its effects on Arabidopsis thaliana primary root were assessed. The effects on root growth, mitotic cell percentage, nitric oxide and hydrogen peroxide levels, the cytoskeleton, cell ultrastructure, auxin and cytokinin activity, and auxin carrier distribution were investigated. It was found that tungsten reduced root growth, particularly by inhibiting cell expansion in the elongation zone, so that root hairs emerged closer to the root tip than in the control. Although extensive vacuolation was observed, even in meristematic cells, cell organelles were almost unaffected and microtubules were not depolymerized but reoriented. Tungsten affected auxin and cytokinin activity, as visualized by the DR5-GFP and TCS-GFP expressing lines, respectively. Cytokinin fluctuations were similar to those of the mitotic cell percentage. DR5-GFP signal appeared ectopically expressed, while the signals of PIN2-GFP and PIN3-GFP were diminished even after relatively short exposures. The observed effects were not reminiscent of those of any nitric oxide scavengers. Taken together, inhibition of root growth by tungsten might rather be related to a presumed interference with the basipetal flow of auxin, specifically affecting cell expansion in the elongation zone.
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Affiliation(s)
| | - Emmanuel Panteris
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece
| | - Eleftherios P Eleftheriou
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece
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97
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Singh M, Gupta A, Laxmi A. Glucose control of root growth direction in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2981-93. [PMID: 24719453 PMCID: PMC4071822 DOI: 10.1093/jxb/eru146] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Directional growth of roots is a complex process that is modulated by various environmental signals. This work shows that presence of glucose (Glc) in the medium also extensively modulated seedling root growth direction. Glc modulation of root growth direction was dramatically enhanced by simultaneous brassinosteroid (BR) application. Glc enhanced BR receptor BRASSINOSTEROID INSENSITIVE1 (BRI1) endocytosis from plasma membrane to early endosomes. Glc-induced root deviation was highly enhanced in a PP2A-defective mutant, roots curl in naphthyl phthalamic acid 1-1 (rcn1-1) suggesting that there is a role of phosphatase in Glc-induced root-growth deviation. RCN1, therefore, acted as a link between Glc and the BR-signalling pathway. Polar auxin transport worked further downstream to BR in controlling Glc-induced root deviation response. Glc also affected other root directional responses such as root waving and coiling leading to altered root architecture. High light intensity mimicked the Glc-induced changes in root architecture that were highly reduced in Glc-signalling mutants. Thus, under natural environmental conditions, changing light flux in the environment may lead to enhanced Glc production/response and is a way to manipulate root architecture for optimized development via integrating several extrinsic and intrinsic signalling cues.
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Affiliation(s)
- Manjul Singh
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Aditi Gupta
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Ashverya Laxmi
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
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98
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Rice actin-binding protein RMD is a key link in the auxin-actin regulatory loop that controls cell growth. Proc Natl Acad Sci U S A 2014; 111:10377-82. [PMID: 24982173 DOI: 10.1073/pnas.1401680111] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The plant hormone auxin plays a central role in plant growth and development. Auxin transport and signaling depend on actin organization. Despite its functional importance, the mechanistic link between actin filaments (F-actin) and auxin intracellular signaling remains unclear. Here, we report that the actin-organizing protein Rice Morphology Determinant (RMD), a type II formin from rice (Oryza sativa), provides a key link. Mutants lacking RMD display abnormal cell growth and altered configuration of F-actin array direction. The rmd mutants also exhibit an inhibition of auxin-mediated cell elongation, decreased polar auxin transport, altered auxin distribution gradients in root tips, and suppression of plasma membrane localization of auxin transporters O. sativa PIN-FORMED 1b (OsPIN1b) and OsPIN2 in root cells. We demonstrate that RMD is required for endocytosis, exocytosis, and auxin-mediated OsPIN2 recycling to the plasma membrane. Moreover, RMD expression is directly regulated by heterodimerized O. sativa auxin response factor 23 (OsARF23) and OsARF24, providing evidence that auxin modulates the orientation of F-actin arrays through RMD. In support of this regulatory loop, osarf23 and lines with reduced expression of both OsARF23 and OsARF24 display reduced RMD expression, disrupted F-actin organization and cell growth, less sensitivity to auxin response, and altered auxin distribution and OsPIN localization. Our findings establish RMD as a crucial component of the auxin-actin self-organizing regulatory loop from the nucleus to cytoplasm that controls rice cell growth and morphogenesis.
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99
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Dyachok J, Sparks JA, Liao F, Wang YS, Blancaflor EB. Fluorescent protein-based reporters of the actin cytoskeleton in living plant cells: Fluorophore variant, actin binding domain, and promoter considerations. Cytoskeleton (Hoboken) 2014; 71:311-27. [DOI: 10.1002/cm.21174] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 02/27/2014] [Accepted: 03/19/2014] [Indexed: 12/28/2022]
Affiliation(s)
- Julia Dyachok
- Plant Biology Division; The Samuel Roberts Noble Foundation; Ardmore Oklahoma
| | - J. Alan Sparks
- Plant Biology Division; The Samuel Roberts Noble Foundation; Ardmore Oklahoma
| | - Fuqi Liao
- Department of Computing Services; The Samuel Roberts Noble Foundation; Ardmore Oklahoma
| | - Yuh-Shuh Wang
- Plant Signal Research Group; Institute of Technology, University of Tartu; Nooruse 1 Tartu 50411 Estonia
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100
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Dürr J, Lolas IB, Sørensen BB, Schubert V, Houben A, Melzer M, Deutzmann R, Grasser M, Grasser KD. The transcript elongation factor SPT4/SPT5 is involved in auxin-related gene expression in Arabidopsis. Nucleic Acids Res 2014; 42:4332-47. [PMID: 24497194 PMCID: PMC3985667 DOI: 10.1093/nar/gku096] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/21/2013] [Accepted: 01/09/2014] [Indexed: 11/28/2022] Open
Abstract
The heterodimeric complex SPT4/SPT5 is a transcript elongation factor (TEF) that directly interacts with RNA polymerase II (RNAPII) to regulate messenger RNA synthesis in the chromatin context. We provide biochemical evidence that in Arabidopsis, SPT4 occurs in a complex with SPT5, demonstrating that the SPT4/SPT5 complex is conserved in plants. Each subunit is encoded by two genes SPT4-1/2 and SPT5-1/2. A mutant affected in the tissue-specifically expressed SPT5-1 is viable, whereas inactivation of the generally expressed SPT5-2 is homozygous lethal. RNAi-mediated downregulation of SPT4 decreases cell proliferation and causes growth reduction and developmental defects. These plants display especially auxin signalling phenotypes. Consistently, auxin-related genes, most strikingly AUX/IAA genes, are downregulated in SPT4-RNAi plants that exhibit an enhanced auxin response. In Arabidopsis nuclei, SPT5 clearly localizes to the transcriptionally active euchromatin, and essentially co-localizes with transcribing RNAPII. Typical for TEFs, SPT5 is found over the entire transcription unit of RNAPII-transcribed genes. In SPT4-RNAi plants, elevated levels of RNAPII and SPT5 are detected within transcribed regions (including those of downregulated genes), indicating transcript elongation defects in these plants. Therefore, SPT4/SPT5 acts as a TEF in Arabidopsis, regulating transcription during the elongation stage with particular impact on the expression of certain auxin-related genes.
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Affiliation(s)
- Julius Dürr
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Ihab B. Lolas
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Brian B. Sørensen
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Veit Schubert
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Andreas Houben
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Michael Melzer
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Rainer Deutzmann
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Marion Grasser
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Klaus D. Grasser
- Department of Cell Biology & Plant Biochemistry, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany and Institute for Biochemistry I, Biochemie-Zentrum Regensburg (BZR), University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
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