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Pavlović I, Pěnčík A, Novák O, Vujčić V, Radić Brkanac S, Lepeduš H, Strnad M, Salopek-Sondi B. Short-term salt stress in Brassica rapa seedlings causes alterations in auxin metabolism. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 125:74-84. [PMID: 29427890 DOI: 10.1016/j.plaphy.2018.01.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 01/09/2018] [Accepted: 01/26/2018] [Indexed: 05/13/2023]
Abstract
Salinity is one of major abiotic stresses affecting Brassica crop production. Here we present investigations into the physiological, biochemical, and hormonal components of the short-term salinity stress response in Chinese cabbage seedlings, with particular emphasis on the biosynthesis and metabolism of auxin indole-3-acetic acid (IAA). Upon salinity treatments (50-200 mM NaCl) IAA level was elevated in a dose dependent manner reaching 1.6-fold increase at the most severe salt treatment in comparison to the control. IAA precursor profiling suggested that salinity activated the indole-3-acetamide and indole-3-acetaldoxime biosynthetic pathways while suppressing the indole-3-pyruvic acid pathway. Levels of the IAA catabolites 2-oxoindole-3-acetic acid and indole-3-acetic acid-aspartate increased 1.7- and 2.0-fold, respectively, under the most severe treatment, in parallel with those of IAA. Conversely, levels of the ester conjugate indole-3-acetyl-1-O-ß-d-glucose and its catabolite 2-oxoindole-3-acetyl-1-O-ß-d-glucose decreased 2.5- and 7.0-fold, respectively. The concentrations of stress hormones including jasmonic acid and jasmonoyl-isoleucine (JA and JA-Ile), salicylic acid (SA) and abscisic acid (ABA) confirmed the stress induced by salt treatment: levels of JA and JA-Ile increased strongly under the mildest treatment, ABA only increased under the most severe treatment, and SA levels decreased dose-dependently. These hormonal changes were related to the observed changes in biochemical stress markers upon salt treatments: reductions in seedling fresh weight and root growth, decreased photosynthesis rate, increased levels of reactive oxygen species, and elevated proline content and the Na+/K+ ratio. Correlations among auxin profile and biochemical stress markers were discussed based on Pearson's coefficients and principal component analysis (PCA).
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Affiliation(s)
- Iva Pavlović
- Department of Molecular Biology, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
| | - Aleš Pěnčík
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR & Faculty of Science of Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR & Faculty of Science of Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
| | - Valerija Vujčić
- Department of Botany, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia
| | - Sandra Radić Brkanac
- Department of Botany, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia
| | - Hrvoje Lepeduš
- Faculty of Humanities and Social Sciences, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR & Faculty of Science of Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
| | - Branka Salopek-Sondi
- Department of Molecular Biology, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia.
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202
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Ng JLP, Mathesius U. Acropetal Auxin Transport Inhibition Is Involved in Indeterminate But Not Determinate Nodule Formation. FRONTIERS IN PLANT SCIENCE 2018; 9:169. [PMID: 29497432 PMCID: PMC5818462 DOI: 10.3389/fpls.2018.00169] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/30/2018] [Indexed: 05/23/2023]
Abstract
Legumes enter into a symbiotic relationship with nitrogen-fixing rhizobia, leading to nodule development. Two main types of nodules have been widely studied, indeterminate and determinate, which differ in the location of the first cell division in the root cortex, and persistency of the nodule meristem. Here, we compared the control of auxin transport, content, and response during the early stages of indeterminate and determinate nodule development in the model legumes Medicago truncatula and Lotus japonicus, respectively, to investigate whether differences in auxin transport control could explain the differences in the location of cortical cell divisions. While auxin responses were activated in dividing cortical cells during nodulation of both nodule types, auxin (indole-3-acetic acid) content at the nodule initiation site was transiently increased in M. truncatula, but transiently reduced in L. japonicus. Root acropetal auxin transport was reduced in M. truncatula at the very start of nodule initiation, in contrast to a prolonged increase in acropetal auxin transport in L. japonicus. The auxin transport inhibitors 2,3,5-triiodobenzoic acid and 1-N-naphthylphthalamic acid (NPA) only induced pseudonodules in legume species forming indeterminate nodules, but failed to elicit such structures in a range of species forming determinate nodules. The development of these pseudonodules in M. truncatula exhibited increased auxin responses in a small primordium formed from the pericycle, endodermis, and inner cortex, similar to rhizobia-induced nodule primordia. In contrast, a diffuse cortical auxin response and no associated cortical cell divisions were found in L. japonicus. Collectively, we hypothesize that a step of acropetal auxin transport inhibition is unique to the process of indeterminate nodule development, leading to auxin responses in pericycle, endodermis, and inner cortex cells, while increased auxin responses in outer cortex cells likely require a different mechanism during the formation of determinate nodules.
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Affiliation(s)
- Jason L. P. Ng
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, ACT, Australia
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203
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Sherp AM, Westfall CS, Alvarez S, Jez JM. Arabidopsis thaliana GH3.15 acyl acid amido synthetase has a highly specific substrate preference for the auxin precursor indole-3-butyric acid. J Biol Chem 2018; 293:4277-4288. [PMID: 29462792 DOI: 10.1074/jbc.ra118.002006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/05/2018] [Indexed: 12/29/2022] Open
Abstract
Various phytohormones control plant growth and development and mediate biotic and abiotic stress responses. Gretchen Hagen 3 (GH3) acyl acid amido synthetases are plant enzymes that typically conjugate amino acids to indole-3-acetic acid (IAA) or jasmonic acid (JA) to inactivate or activate these phytohormones, respectively; however, the physiological and biological roles of many of these enzymes remain unclear. Using a biochemical approach, we found that the Arabidopsis thaliana GH3.15 (AtGH3.15) preferentially uses indole-3-butyric acid (IBA) and glutamine as substrates. The X-ray crystal structure of the AtGH3.15·AMP complex, modeling of IBA in the active site, and biochemical analysis of site-directed mutants provide insight on active site features that lead to AtGH3.15's preference for IBA. Assay-based in planta analysis of AtGH3.15-overexpressing lines indicated that their root elongation and lateral root density were resistant to IBA treatment but not to treatment with either IAA or JA. These findings suggest that AtGH3.15 may play a role in auxin homeostasis by modulating the levels of IBA for peroxisomal conversion to IAA. Analysis of AtGH3.15 promoter-driven yellow fluorescent protein reporter lines revealed that AtGH3.15 is expressed at significant levels in seedlings, roots, and parts of the siliques. We conclude that AtGH3.15 is unique in the GH3 protein family for its role in modifying IBA in auxin homeostasis and that it is the first GH3 protein shown to primarily modify a plant growth regulator other than IAA and JA.
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Affiliation(s)
- Ashley M Sherp
- From the Department of Biology, Washington University, St. Louis, Missouri 63130 and
| | - Corey S Westfall
- From the Department of Biology, Washington University, St. Louis, Missouri 63130 and
| | - Sophie Alvarez
- the Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68588
| | - Joseph M Jez
- From the Department of Biology, Washington University, St. Louis, Missouri 63130 and
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204
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Du J, Jiang H, Sun X, Li Y, Liu Y, Sun M, Fan Z, Cao Q, Feng L, Shang J, Shu K, Liu J, Yang F, Liu W, Yong T, Wang X, Yuan S, Yu L, Liu C, Yang W. Auxin and Gibberellins Are Required for the Receptor-Like Kinase ERECTA Regulated Hypocotyl Elongation in Shade Avoidance in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2018; 9:124. [PMID: 29467786 PMCID: PMC5808342 DOI: 10.3389/fpls.2018.00124] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 01/23/2018] [Indexed: 05/27/2023]
Abstract
Plants use shade avoidance strategy to escape the canopy shade when grown under natural conditions. Previous studies showed that the Arabidopsis receptor-like kinase ERECTA (ER) is involved in shade avoidance syndrome. However, the mechanisms of ER in modulating SAR by promoting hypocotyl elongation are unknown yet. Here, we report that ER regulated hypocotyl elongation in shade avoidance requires auxin and gibberellins (GAs). The T-DNA insertional ER mutant er-3 shows a less hypocotyl length than that in Col-0 wild type. Promoter::GUS staining analysis shows that ER and its paralogous genes ERECTA-LIKE1 (ERL1) and ERECTA-LIKE2 (ERL2) are differentially expressed in the seedlings, of which only ER is most obviously upregulated in the hypocotyl by shade treatment. Exogenous feeding assay by using media-application with vertical-grown of Arabidopsis seedlings showed that the hypocotyl length of er-3 is partially promoted by indol-3-acetic acid (IAA), while it is relatively insensitive of er-3 to various concentrations of IAA than that of Col-0. Hypocotyl elongation of er-3 is promoted similar to that of Col-0 by high temperature in the white light condition, but the elongation was not significantly affected by the treatment of the auxin transport inhibitor 1-N-naphthylphthalamic acid (NPA). Exogenous GA3 increased the hypocotyl elongation of both er-3 and the wild type in the shade condition, and the GA3 biosynthesis inhibitor paclobutrazol (PAC) severely inhibits the hypocotyl elongation of Col-0 and er-3. Further analysis showed that auxin biosynthesis inhibitors yucasin and L-kynurenine remarkably inhibited the hypocotyl elongation of er-3 while yucasin shows a more severe inhibition to er-3 than Col-0. Relative expression of genes regulating auxin homeostasis and signaling, and GA homeostasis is less in er-3 than that in Col-0. Furthermore, genetic evidences show that ER regulated hypocotyl elongation is dependent of PHYTOCHROME B (PHYB). Overall, we propose that ER regulated shade avoidance by promoting hypocotyl elongation is PHYB-dependent and requires auxin and GAs.
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Affiliation(s)
- Junbo Du
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Hengke Jiang
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Xin Sun
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Yan Li
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Yi Liu
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
| | - Mengyuan Sun
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Zhou Fan
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
| | - Qiulin Cao
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
| | - Lingyang Feng
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Jing Shang
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Kai Shu
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Jiang Liu
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Feng Yang
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Weiguo Liu
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Taiwen Yong
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Xiaochun Wang
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Shu Yuan
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Liang Yu
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Chunyan Liu
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Wenyu Yang
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
- Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Crop Ecophysiology and Farming System in Southwest China – Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China
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205
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Hui WK, Wang Y, Chen XY, Zayed MZ, Wu GJ. Analysis of Transcriptional Responses of the Inflorescence Meristems in Jatropha curcas Following Gibberellin Treatment. Int J Mol Sci 2018; 19:ijms19020432. [PMID: 29389867 PMCID: PMC5855654 DOI: 10.3390/ijms19020432] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/16/2018] [Accepted: 01/25/2018] [Indexed: 12/25/2022] Open
Abstract
Jatropha curcas L. seeds an oilseed plant with great potential for biodiesel production. However, low seed yield, which was limited by its lower female flowers, was a major drawback for its utilization. Our previous study found that the flower number and female-to-male ratio were increased by gibberellin treatment. Here, we compared the transcriptomic profiles of inflorescence meristem at different time points after gibberellic acid A3 (GA3) treatment. The present study showed that 951 differentially expressed genes were obtained in response to gibberellin treatment, compared with control samples. The 6-h time point was an important phase in the response to exogenous gibberellin. Furthermore, the plant endogenous gibberellin, auxin, ethylene, abscisic acid, and brassinolide-signaling transduction pathways were repressed, whereas the genes associated with cytokinin and jasmonic acid signaling were upregulated for 24-h time point following GA3 treatment. In addition, the floral meristem determinacy genes (JcLFY, JcSOC1) and floral organ identity genes (JcAP3, JcPI, JcSEP1-3) were significantly upregulated, but their negative regulator (JcSVP) was downregulated after GA3 treatment. Moreover, the effects of phytohormone, which was induced by exogenous plant growth regulator, mainly acted on the female floral differentiation process. To the best of our knowledge, this data is the first comprehensive analysis of the underlying transcriptional response mechanism of floral differentiation following GA3 treatment in J. curcas, which helps in engineering high-yielding varieties of Jatropha.
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Affiliation(s)
- Wen-Kai Hui
- National Engineering Laboratory for Forest Tree Breeding, College of Biological Science and Technology, Beijing Forestry University, Beijing 100083, China.
| | - Yi Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.
| | - Xiao-Yang Chen
- National Engineering Laboratory for Forest Tree Breeding, College of Biological Science and Technology, Beijing Forestry University, Beijing 100083, China.
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.
| | - Mohamed Zaky Zayed
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.
- Forestry and Wood Technology Department, Faculty of Agriculture (EL-Shatby), Alexandria University, Alexandria 21527, Egypt.
| | - Guo-Jiang Wu
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
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206
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Weijers D, Nemhauser J, Yang Z. Auxin: small molecule, big impact. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:133-136. [PMID: 29309681 PMCID: PMC5853209 DOI: 10.1093/jxb/erx463] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- Dolf Weijers
- Wageningen University & Research, Laboratory of Biochemistry, The Netherlands
- Correspondence:
| | | | - Zhenbiao Yang
- Institute of Integrative Genome Biology and Department of Botany and Plant Sciences, University of California, USA
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, China
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207
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Frick EM, Strader LC. Roles for IBA-derived auxin in plant development. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:169-177. [PMID: 28992091 PMCID: PMC5853464 DOI: 10.1093/jxb/erx298] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/01/2017] [Indexed: 05/18/2023]
Abstract
The plant hormone auxin is a central regulator of plant growth and development. Because auxin plays critical roles in cell division and cell expansion, plants use a number of cellular mechanisms to regulate auxin levels and response. Among these mechanisms is regulated input from the auxin precursor indole-3-butyric acid (IBA) toward the pool of active auxin [indole-3-acetic acid (IAA)]. In this review, we cover the mechanisms of IBA transport and conversion, and discuss specific roles for IBA-derived auxin in driving certain developmental events. We further discuss multiple open questions remaining for the IBA field.
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Affiliation(s)
- Elizabeth M Frick
- NSF Science and Technology Center for Engineering Mechanobiology, Department of Biology, Washington University in St. Louis, USA
| | - Lucia C Strader
- NSF Science and Technology Center for Engineering Mechanobiology, Department of Biology, Washington University in St. Louis, USA
- Correspondence:
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208
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Kunkel BN, Harper CP. The roles of auxin during interactions between bacterial plant pathogens and their hosts. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:245-254. [PMID: 29272462 DOI: 10.1093/jxb/erx447] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Plant pathogens have evolved several strategies to manipulate the biology of their hosts to facilitate colonization, growth to high levels in plant tissue, and production of disease. One of the less well known of these strategies is the synthesis of plant hormones and hormone analogs, and there is growing evidence that modulation of host hormone signaling is important during pathogenesis. Several plant pathogens produce the auxin indole-3-acetic acid (IAA) and/or virulence factors that modulate host auxin signaling. Auxin is well known for being involved in many aspects of plant growth and development, but recent findings have revealed that elevated IAA levels or enhanced auxin signaling can also promote disease development in some plant-pathogen interactions. In addition to stimulating plant cell growth during infection by gall-forming bacteria, auxin and auxin signaling can antagonize plant defense responses. Auxin can also act as a microbial signaling molecule to impact the biology of some pathogens directly. In this review, we summarize recent progress towards elucidating the roles that auxin production, modification of host auxin signaling, and direct effects of auxin on pathogens play during pathogenesis, with emphasis on the impacts of auxin on interactions with bacterial pathogens.
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Affiliation(s)
- Barbara N Kunkel
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
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209
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Ma Q, Grones P, Robert S. Auxin signaling: a big question to be addressed by small molecules. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:313-328. [PMID: 29237069 PMCID: PMC5853230 DOI: 10.1093/jxb/erx375] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/16/2017] [Indexed: 05/20/2023]
Abstract
Providing a mechanistic understanding of the crucial roles of the phytohormone auxin has been an important and coherent aspect of plant biology research. Since its discovery more than a century ago, prominent advances have been made in the understanding of auxin action, ranging from metabolism and transport to cellular and transcriptional responses. However, there is a long road ahead before a thorough understanding of its complex effects is achieved, because a lot of key information is still missing. The availability of an increasing number of technically advanced scientific tools has boosted the basic discoveries in auxin biology. A plethora of bioactive small molecules, consisting of the synthetic auxin-like herbicides and the more specific auxin-related compounds, developed as a result of the exploration of chemical space by chemical biology, have made the tool box for auxin research more comprehensive. This review mainly focuses on the compounds targeting the auxin co-receptor complex, demonstrates the various ways to use them, and shows clear examples of important basic knowledge obtained by their usage. Application of these precise chemical tools, together with an increasing amount of structural information for the major components in auxin action, will certainly aid in strengthening our insights into the complexity and diversity of auxin response.
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Affiliation(s)
- Qian Ma
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Sweden
| | - Peter Grones
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Sweden
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210
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Kao YT, Gonzalez KL, Bartel B. Peroxisome Function, Biogenesis, and Dynamics in Plants. PLANT PHYSIOLOGY 2018; 176:162-177. [PMID: 29021223 PMCID: PMC5761812 DOI: 10.1104/pp.17.01050] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/09/2017] [Indexed: 05/19/2023]
Abstract
Recent advances highlight understanding of the diversity of peroxisome contributions to plant biology and the mechanisms through which these essential organelles are generated.
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Affiliation(s)
- Yun-Ting Kao
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Kim L Gonzalez
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Bonnie Bartel
- Department of Biosciences, Rice University, Houston, Texas 77005
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211
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Olatunji D, Geelen D, Verstraeten I. Control of Endogenous Auxin Levels in Plant Root Development. Int J Mol Sci 2017; 18:E2587. [PMID: 29194427 PMCID: PMC5751190 DOI: 10.3390/ijms18122587] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/26/2017] [Accepted: 11/28/2017] [Indexed: 12/24/2022] Open
Abstract
In this review, we summarize the different biosynthesis-related pathways that contribute to the regulation of endogenous auxin in plants. We demonstrate that all known genes involved in auxin biosynthesis also have a role in root formation, from the initiation of a root meristem during embryogenesis to the generation of a functional root system with a primary root, secondary lateral root branches and adventitious roots. Furthermore, the versatile adaptation of root development in response to environmental challenges is mediated by both local and distant control of auxin biosynthesis. In conclusion, auxin homeostasis mediated by spatial and temporal regulation of auxin biosynthesis plays a central role in determining root architecture.
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Affiliation(s)
- Damilola Olatunji
- Department of Plant Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
| | - Danny Geelen
- Department of Plant Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
| | - Inge Verstraeten
- Department of Plant Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
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Damodaran S, Westfall CS, Kisely BA, Jez JM, Subramanian S. Nodule-Enriched GRETCHEN HAGEN 3 Enzymes Have Distinct Substrate Specificities and Are Important for Proper Soybean Nodule Development. Int J Mol Sci 2017; 18:E2547. [PMID: 29182530 PMCID: PMC5751150 DOI: 10.3390/ijms18122547] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 11/16/2022] Open
Abstract
Legume root nodules develop as a result of a symbiotic relationship between the plant and nitrogen-fixing rhizobia bacteria in soil. Auxin activity is detected in different cell types at different stages of nodule development; as well as an enhanced sensitivity to auxin inhibits, which could affect nodule development. While some transport and signaling mechanisms that achieve precise spatiotemporal auxin output are known, the role of auxin metabolism during nodule development is unclear. Using a soybean root lateral organ transcriptome data set, we identified distinct nodule enrichment of three genes encoding auxin-deactivating GRETCHEN HAGEN 3 (GH3) indole-3-acetic acid (IAA) amido transferase enzymes: GmGH3-11/12, GmGH3-14 and GmGH3-15. In vitro enzymatic assays showed that each of these GH3 proteins preferred IAA and aspartate as acyl and amino acid substrates, respectively. GmGH3-15 showed a broad substrate preference, especially with different forms of auxin. Promoter:GUS expression analysis indicated that GmGH3-14 acts primarily in the root epidermis and the nodule primordium where as GmGH3-15 might act in the vasculature. Silencing the expression of these GH3 genes in soybean composite plants led to altered nodule numbers, maturity, and size. Our results indicate that these GH3s are needed for proper nodule maturation in soybean, but the precise mechanism by which they regulate nodule development remains to be explained.
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Affiliation(s)
- Suresh Damodaran
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57007, USA.
| | - Corey S Westfall
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | - Brian A Kisely
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57007, USA.
| | - Joseph M Jez
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | - Senthil Subramanian
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57007, USA.
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
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213
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Eggert K, von Wirén N. Response of the plant hormone network to boron deficiency. THE NEW PHYTOLOGIST 2017; 216:868-881. [PMID: 28833172 DOI: 10.1111/nph.14731] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/30/2017] [Indexed: 05/04/2023]
Abstract
Plant hormones (PH) adjust plant growth to environmental conditions such as nutrient availability. Although responses of individual PHs to growth-determining nutrient supplies have been reported, little is known about simultaneous dynamics in the metabolism of different PH species. Brassica napus seedlings were grown under increasing supply of B, and LC-MS/MS was used to characterize bioactive forms of different PH species together with several of their precursors, storage and inactivated forms. Increasing shoot B concentrations in response to B supply were accompanied by decreasing concentrations of abscisic acid (ABA) and indole-3-acetic acid (IAA), which appeared to be synthesized under B deficiency mainly via indole-3-acetonitrile (IAN). By contrast, shoot B concentrations correlated closely with cytokinins, and the B-dependent growth response appeared to be triggered primarily by de-novo synthesis of cytokinins and by re-routing less active towards highly active forms of cytokinin. Also gibberellin biosynthesis strongly increased with B supply, in particular gibberellin species from the non-13-hydroxylation pathway. The brassinosteroid castasterone appeared to support shoot growth primarily at suboptimal B nutrition. These results indicate that a variable B nutritional status causes coordinated changes in PH metabolism as prerequisite for an adjusted growth response.
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Affiliation(s)
- Kai Eggert
- Molecular Plant Nutrition, Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstraße 3, 06466, Gatersleben, Germany
| | - Nicolaus von Wirén
- Molecular Plant Nutrition, Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstraße 3, 06466, Gatersleben, Germany
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214
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Mechanisms of action of plant growth promoting bacteria. World J Microbiol Biotechnol 2017; 33:197. [PMID: 28986676 PMCID: PMC5686270 DOI: 10.1007/s11274-017-2364-9] [Citation(s) in RCA: 354] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 10/04/2017] [Indexed: 01/01/2023]
Abstract
The idea of eliminating the use of fertilizers which are sometimes environmentally unsafe is slowly becoming a reality because of the emergence of microorganisms that can serve the same purpose or even do better. Depletion of soil nutrients through leaching into the waterways and causing contamination are some of the negative effects of these chemical fertilizers that prompted the need for suitable alternatives. This brings us to the idea of using microbes that can be developed for use as biological fertilizers (biofertilizers). They are environmentally friendly as they are natural living organisms. They increase crop yield and production and, in addition, in developing countries, they are less expensive compared to chemical fertilizers. These biofertilizers are typically called plant growth-promoting bacteria (PGPB). In addition to PGPB, some fungi have also been demonstrated to promote plant growth. Apart from improving crop yields, some biofertilizers also control various plant pathogens. The objective of worldwide sustainable agriculture is much more likely to be achieved through the widespread use of biofertilizers rather than chemically synthesized fertilizers. However, to realize this objective it is essential that the many mechanisms employed by PGPB first be thoroughly understood thereby allowing workers to fully harness the potentials of these microbes. The present state of our knowledge regarding the fundamental mechanisms employed by PGPB is discussed herein.
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215
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Fattorini L, Veloccia A, Della Rovere F, D’Angeli S, Falasca G, Altamura MM. Indole-3-butyric acid promotes adventitious rooting in Arabidopsis thaliana thin cell layers by conversion into indole-3-acetic acid and stimulation of anthranilate synthase activity. BMC PLANT BIOLOGY 2017; 17:121. [PMID: 28693423 PMCID: PMC5504571 DOI: 10.1186/s12870-017-1071-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/29/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Indole-3-acetic acid (IAA), and its precursor indole-3-butyric acid (IBA), control adventitious root (AR) formation in planta. Adventitious roots are also crucial for propagation via cuttings. However, IBA role(s) is/are still far to be elucidated. In Arabidopsis thaliana stem cuttings, 10 μM IBA is more AR-inductive than 10 μM IAA, and, in thin cell layers (TCLs), IBA induces ARs when combined with 0.1 μM kinetin (Kin). It is unknown whether arabidopsis TCLs produce ARs under IBA alone (10 μM) or IAA alone (10 μM), and whether they contain endogenous IAA/IBA at culture onset, possibly interfering with the exogenous IBA/IAA input. Moreover, it is unknown whether an IBA-to-IAA conversion is active in TCLs, and positively affects AR formation, possibly through the activity of the nitric oxide (NO) deriving from the conversion process. RESULTS Revealed undetectable levels of both auxins at culture onset, showing that arabidopsis TCLs were optimal for investigating AR-formation under the total control of exogenous auxins. The AR-response of TCLs from various ecotypes, transgenic lines and knockout mutants was analyzed under different treatments. It was shown that ARs are better induced by IBA than IAA and IBA + Kin. IBA induced IAA-efflux (PIN1) and IAA-influx (AUX1/LAX3) genes, IAA-influx carriers activities, and expression of ANTHRANILATE SYNTHASE -alpha1 (ASA1), a gene involved in IAA-biosynthesis. ASA1 and ANTHRANILATE SYNTHASE -beta1 (ASB1), the other subunit of the same enzyme, positively affected AR-formation in the presence of exogenous IBA, because the AR-response in the TCLs of their mutant wei2wei7 was highly reduced. The AR-response of IBA-treated TCLs from ech2ibr10 mutant, blocked into IBA-to-IAA-conversion, was also strongly reduced. Nitric oxide, an IAA downstream signal and a by-product of IBA-to-IAA conversion, was early detected in IAA- and IBA-treated TCLs, but at higher levels in the latter explants. CONCLUSIONS Altogether, results showed that IBA induced AR-formation by conversion into IAA involving NO activity, and by a positive action on IAA-transport and ASA1/ASB1-mediated IAA-biosynthesis. Results are important for applications aimed to overcome rooting recalcitrance in species of economic value, but mainly for helping to understand IBA involvement in the natural process of adventitious rooting.
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Affiliation(s)
- L. Fattorini
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - A. Veloccia
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - F. Della Rovere
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - S. D’Angeli
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - G. Falasca
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - M. M. Altamura
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
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216
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Kumar P, Kesari P, Dhindwal S, Choudhary AK, Katiki M, Neetu, Verma A, Ambatipudi K, Tomar S, Sharma AK, Mishra G, Kumar P. A novel function for globulin in sequestering plant hormone: Crystal structure of Wrightia tinctoria 11S globulin in complex with auxin. Sci Rep 2017; 7:4705. [PMID: 28680092 PMCID: PMC5498579 DOI: 10.1038/s41598-017-04518-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 05/17/2017] [Indexed: 11/20/2022] Open
Abstract
Auxin levels are tightly regulated within the plant cell, and its storage in the isolated cavity of proteins is a measure adopted by cells to maintain the availability of auxin. We report the first crystal structure of Wrightia tinctoria 11S globulin (WTG) in complex with Indole-3-acetic acid (IAA), an auxin, at 1.7 Å resolution. WTG hexamers assemble as a result of the stacking interaction between the hydrophobic surfaces of two trimers, leaving space for the binding of charged ligands. The bound auxin is stabilized by non-covalent interactions, contributed by four chains in each cavity. The presence of bound ligand was confirmed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and high-resolution mass spectrometry (HRMS). Here, we hypothesize that the cleavage of globulins by endopeptidases leads to the movement of the hydrophilic loop region from the surface to the periphery, leaving space for the binding of auxin, and promotes hexamer formation. As the process of germination proceeds, there is a change in the pH, which induces the dissociation of the hexamer and the release of auxin. The compact hexameric assembly ensures the long-term, stable storage of the hormone. This suggests a role for globulin as a novel player in auxin homeostasis.
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Affiliation(s)
- Pramod Kumar
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Pooja Kesari
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Sonali Dhindwal
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | | | - Madhusudhanarao Katiki
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Neetu
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Aparna Verma
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Kiran Ambatipudi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Shailly Tomar
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Ashwani Kumar Sharma
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Girish Mishra
- Department of Botany, University of Delhi, Delhi, 110007, India
| | - Pravindra Kumar
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.
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217
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Yu Y, Duan X, Ding X, Chen C, Zhu D, Yin K, Cao L, Song X, Zhu P, Li Q, Nisa ZU, Yu J, Du J, Song Y, Li H, Liu B, Zhu Y. A novel AP2/ERF family transcription factor from Glycine soja, GsERF71, is a DNA binding protein that positively regulates alkaline stress tolerance in Arabidopsis. PLANT MOLECULAR BIOLOGY 2017; 94:509-530. [PMID: 28681139 DOI: 10.1007/s11103-017-0623-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 06/08/2017] [Indexed: 05/07/2023]
Abstract
KEY MESSAGE Here we first found that GsERF71, an ERF factor from wild soybean could increase plant alkaline stress tolerance by up-regulating H+-ATPase and by modifing the accumulation of Auxin. Alkaline soils are widely distributed all over the world and greatly limit plant growth and development. In our previous transcriptome analyses, we have identified several ERF (ethylene-responsive factor) genes that responded strongly to bicarbonate stress in the roots of wild soybean G07256 (Glycine soja). In this study, we cloned and functionally characterized one of the genes, GsERF71. When expressed in epidermal cells of onion, GsERF71 localized to the nucleus. It can activate the reporters in yeast cells, and the C-terminus of 170 amino acids is essential for its transactivation activity. Yeast one-hybrid and EMSA assays indicated that GsERF71 specifically binds to the cis-acting elements of the GCC-box, suggesting that GsERF71 may participate in the regulation of transcription of the relevant biotic and abiotic stress-related genes. Furthermore, transgenic Arabidopsis plants overexpressing GsERF71 showed significantly higher tolerance to bicarbonate stress generated by NaHCO3 or KHCO3 than the wild type (WT) plants, i.e., the transgenic plants had greener leaves, longer roots, higher total chlorophyll contents and lower MDA contents. qRT-PCR and rhizosphere acidification assays indicated that the expression level and activity of H+-ATPase (AHA2) were enhanced in the transgenic plants under alkaline stress. Further analysis indicated that the expression of auxin biosynthetic genes and IAA contents were altered to a lower extent in the roots of transgenic plants than WT plants under alkaline stress in a short-term. Together, our data suggest that GsERF71 enhances the tolerance to alkaline stress by up-regulating the expression levels of H+-ATPase and by modifying auxin accumulation in transgenic plants.
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Affiliation(s)
- Yang Yu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Xiangbo Duan
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Xiaodong Ding
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Chao Chen
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Dan Zhu
- College of Life Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Kuide Yin
- School of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, 163319, China
| | - Lei Cao
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Xuewei Song
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Pinghui Zhu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Qiang Li
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Zaib Un Nisa
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Jiyang Yu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Jianying Du
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Yu Song
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Huiqing Li
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Beidong Liu
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, 413, Sweden
| | - Yanming Zhu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China.
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218
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Denisov Y, Glick S, Zviran T, Ish-Shalom M, Levin A, Faigenboim A, Cohen Y, Irihimovitch V. Distinct organ-specific and temporal expression profiles of auxin-related genes during mango fruitlet drop. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 115:439-448. [PMID: 28456120 DOI: 10.1016/j.plaphy.2017.04.021] [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: 12/19/2016] [Revised: 03/26/2017] [Accepted: 04/23/2017] [Indexed: 06/07/2023]
Abstract
In mango, fruitlet abscission initiates with a decrease in polar auxin transport through the abscission zone (AZ), triggered by ethylene. To explore the molecular components affecting this process, we initially conducted experiments with developing fruitlet explants in which fruitlet drop was induced by ethephon, and monitored the expression patterns of distinct indole-3-acetic acid (IAA)-related genes, comparing control vs. ethephon-treated pericarp and AZ profiles. Over the examined time period (48 h), the accumulation of MiPIN1 and MiLAX2 IAA-efflux and influx genes decreased in both control and treated tissues. Nevertheless, ethephon-treated tissues displayed significantly lower levels of these transcripts within 18-24 h. An opposite pattern was observed for MiLAX3, which overall exhibited up-regulation in treated fruitlet tissues. Ethephon treatment also induced an early and pronounced down-regulation of five out of six IAA-responsive genes, and a substantial reduction in the accumulation of two IAA-synthesis related transcripts, contrasting with significant up-regulation of Gretchen Hagen3 transcript (MiGH3.1) encoding an IAA-amino synthetase. Furthermore, for both control and treated AZ, the decrease in IAA-carrier transcripts was associated with a decrease in IAA content and an increase in IAA-Asp:IAA ratio, suggesting that fruitlet drop is accompanied by formation of this non-hydrolyzed IAA-amino acid conjugate. Despite these similarities, ethephon-treated AZ displayed a sharper decrease in IAA content and higher IAA-Asp:IAA ratio within 18 h. Lastly, the response of IAA-related genes to exogenous IAA treatment was also examined. Our results are discussed, highlighting the roles that distinct IAA-related genes might assume during mango fruitlet drop.
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Affiliation(s)
- Youlia Denisov
- Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet-Dagan 50250, Israel
| | - Shani Glick
- Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet-Dagan 50250, Israel; Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Tali Zviran
- Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet-Dagan 50250, Israel
| | - Mazal Ish-Shalom
- Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet-Dagan 50250, Israel
| | - Adolfo Levin
- Migal - Galilee Technology Center, P.O. Box 831, Kiryat Shemona 11016, Israel
| | - Adi Faigenboim
- Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet-Dagan 50250, Israel
| | - Yuval Cohen
- Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet-Dagan 50250, Israel
| | - Vered Irihimovitch
- Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet-Dagan 50250, Israel.
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219
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Han EH, Petrella DP, Blakeslee JJ. 'Bending' models of halotropism: incorporating protein phosphatase 2A, ABCB transporters, and auxin metabolism. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3071-3089. [PMID: 28899081 DOI: 10.1093/jxb/erx127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Salt stress causes worldwide reductions in agricultural yields, a problem that is exacerbated by the depletion of global freshwater reserves and the use of contaminated or recycled water (i.e. effluent water). Additionally, salt stress can occur as cultivated areas are subjected to frequent rounds of irrigation followed by periods of moderate to severe evapotranspiration, which can result in the heterogeneous aggregation of salts in agricultural soils. Our understanding of the later stages of salt stress and the mechanisms by which salt is transported out of cells and roots has greatly improved over the last decade. The precise mechanisms by which plant roots perceive salt stress and translate this perception into adaptive, directional growth away from increased salt concentrations (i.e. halotropism), however, are not well understood. Here, we provide a review of the current knowledge surrounding the early responses to salt stress and the initiation of halotropism, including lipid signaling, protein phosphorylation cascades, and changes in auxin metabolism and/or transport. Current models of halotropism have focused on the role of PIN2- and PIN1-mediated auxin efflux in initiating and controlling halotropism. Recent studies, however, suggest that additional factors such as ABCB transporters, protein phosphatase 2A activity, and auxin metabolism should be included in the model of halotropic growth.
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Affiliation(s)
- Eun Hyang Han
- Department of Horticulture and Crop Science, The Ohio State University/OARDC, Wooster, OH, USA
| | - Dominic P Petrella
- Department of Horticulture and Crop Science, The Ohio State University/OARDC, Wooster, OH, USA
| | - Joshua J Blakeslee
- Department of Horticulture and Crop Science, OARDC Metabolite Analysis Cluster (OMAC), The Ohio State University/OARDC, Wooster, OH, USA
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220
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Abstract
Nearly all programmed and plastic plant growth responses are at least partially regulated by auxins, such as indole-3-acetic acid (IAA). Although vectorial, long distance auxin transport is essential to its regulatory function, all auxin responses are ultimately localized in individual target cells. As a consequence, cellular auxin concentrations are tightly regulated via coordinated biosynthesis, transport, conjugation, and oxidation. The primary auxin oxidative product across species is 2-oxindole-3-acetic acid (oxIAA), followed by glucose and amino acid conjugation to oxIAA. Recently, the enzymes catalyzing the oxidative reaction were characterized in Arabidopsis thaliana. DIOXYGENASE OF AUXIN OXIDATION (DAO) comprises a small subfamily of the 2-oxoglutarate and Fe(II) [2-OG Fe(II)] dependent dioxygenase superfamily. Biochemical and genetic studies have revealed critical physiological functions of DAO during plant growth and development. Thus far, DAO has been identified in three species by homology. Here, we review historical and recent studies and discuss future perspectives regarding DAO and IAA oxidation.
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Affiliation(s)
- Jun Zhang
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742,USA
| | - Wendy Ann Peer
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA
- Department of Environmental Science and Technology, University of Maryland, College Park, MD 20742, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD 20742, USA
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221
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Liu H, Able AJ, Able JA. Genotypic water-deficit stress responses in durum wheat: association between physiological traits, microRNA regulatory modules and yield components. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:538-551. [PMID: 32480586 DOI: 10.1071/fp16294] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 02/07/2017] [Indexed: 06/11/2023]
Abstract
In Mediterranean environments, water-deficit stress that occurs before anthesis significantly limits durum wheat (Triticum turgidum L. ssp. durum) production. Stress tolerant and stress sensitive durum varieties exhibit genotypic differences in their response to pre-anthesis water-deficit stress as reflected by yield performance, but our knowledge of the mechanisms underlying tolerance is limited. We have previously identified stress responsive durum microRNAs (miRNAs) that could contribute to water-deficit stress tolerance by mediating post-transcriptional silencing of genes that lead to stress adaptation (e.g. miR160 and its targets ARF8 (auxin response factor 8) and ARF18). However, the temporal regulation pattern of miR160-ARFs after induction of pre-anthesis water-deficit stress in sensitive and tolerant varieties remains unknown. Here, the physiological responses of four durum genotypes are described by chlorophyll content, leaf relative water content, and stomatal conductance at seven time-points during water-deficit stress from booting to anthesis. qPCR examination of miR160, ARF8 and ARF18 at these time-points revealed a complex stress responsive regulatory pattern, in the flag leaf and the head, subject to genotype. Harvest components and morphological traits measured at maturity confirmed the stress tolerance level of these four varieties for agronomic performance, and their potential association with the physiological responses. In general, the distinct regulatory pattern of miR160-ARFs among stress tolerant and sensitive durum varieties suggests that miRNA-mediated molecular pathways may contribute to the genotypic differences in the physiological traits, ultimately affecting yield components (e.g. the maintenance of harvest index and grain number).
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Affiliation(s)
- Haipei Liu
- School of Agriculture, Food and Wine, University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, SA 5064, Australia
| | - Amanda J Able
- School of Agriculture, Food and Wine, University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, SA 5064, Australia
| | - Jason A Able
- School of Agriculture, Food and Wine, University of Adelaide, Waite Research Institute, PMB 1, Glen Osmond, SA 5064, Australia
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222
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Urano K, Maruyama K, Jikumaru Y, Kamiya Y, Yamaguchi-Shinozaki K, Shinozaki K. Analysis of plant hormone profiles in response to moderate dehydration stress. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:17-36. [PMID: 27995695 DOI: 10.1111/tpj.13460] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 12/14/2016] [Accepted: 12/14/2016] [Indexed: 05/19/2023]
Abstract
Plant responses to dehydration stress are mediated by highly complex molecular systems involving hormone signaling and metabolism, particularly the major stress hormone abscisic acid (ABA) and ABA-dependent gene expression. To understand the roles of plant hormones and their interactions during dehydration, we analyzed the plant hormone profiles with respect to dehydration responses in Arabidopsis thaliana wild-type (WT) plants and ABA biosynthesis mutants (nced3-2). We developed a procedure for moderate dehydration stress, and then investigated temporal changes in the profiles of ABA, jasmonic acid isoleucine (JA-Ile), salicylic acid (SA), cytokinin (trans-zeatin, tZ), auxin (indole-acetic acid, IAA), and gibberellin (GA4 ), along with temporal changes in the expression of key genes involved in hormone biosynthesis. ABA levels increased in a bi-phasic pattern (at the early and late phases) in response to moderate dehydration stress. JA-Ile levels increased slightly in WT plants and strongly increased in nced3-2 mutant plants at 72 h after the onset of dehydration. The expression profiles of dehydration-inducible genes displayed temporal responses in an ABA-dependent manner. The early phase of ABA accumulation correlated with the expression of touch-inducible genes and was independent of factors involved in the major ABA regulatory pathway, including the ABA-responsive element-binding (AREB/ABF) transcription factor. JA-Ile, SA, and tZ were negatively regulated during the late dehydration response phase. Transcriptome analysis revealed important roles for hormone-related genes in metabolism and signaling during dehydration-induced plant responses.
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Affiliation(s)
- Kaoru Urano
- RIKEN Center for Sustainable Resource Science (CSRS), 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan
| | - Kyonoshin Maruyama
- Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki, 305-8686, Japan
| | - Yusuke Jikumaru
- RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Yuji Kamiya
- RIKEN Center for Sustainable Resource Science (CSRS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | | | - Kazuo Shinozaki
- RIKEN Center for Sustainable Resource Science (CSRS), 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan
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Hu Y, Vandenbussche F, Van Der Straeten D. Regulation of seedling growth by ethylene and the ethylene-auxin crosstalk. PLANTA 2017; 245:467-489. [PMID: 28188422 DOI: 10.1007/s00425-017-2651-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/08/2017] [Indexed: 05/06/2023]
Abstract
This review highlights that the auxin gradient, established by local auxin biosynthesis and transport, can be controlled by ethylene, and steers seedling growth. A better understanding of the mechanisms in Arabidopsis will increase potential applications in crop species. In dark-grown Arabidopsis seedlings, exogenous ethylene treatment triggers an exaggeration of the apical hook, the inhibition of both hypocotyl and root elongation, and radial swelling of the hypocotyl. These features are predominantly based on the differential cell elongation in different cells/tissues mediated by an auxin gradient. Interestingly, the physiological responses regulated by ethylene and auxin crosstalk can be either additive or synergistic, as in primary root and root hair elongation, or antagonistic, as in hypocotyl elongation. This review focuses on the crosstalk of these two hormones at the seedling stage. Before illustrating the crosstalk, ethylene and auxin biosynthesis, metabolism, transport and signaling are briefly discussed.
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Affiliation(s)
- Yuming Hu
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Filip Vandenbussche
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Dominique Van Der Straeten
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium.
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224
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The Use of Auxin Quantification for Understanding Clonal Tree Propagation. FORESTS 2017. [DOI: 10.3390/f8010027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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225
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Žižková E, Kubeš M, Dobrev PI, Přibyl P, Šimura J, Zahajská L, Záveská Drábková L, Novák O, Motyka V. Control of cytokinin and auxin homeostasis in cyanobacteria and algae. ANNALS OF BOTANY 2017; 119:151-166. [PMID: 27707748 PMCID: PMC5218379 DOI: 10.1093/aob/mcw194] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/18/2016] [Accepted: 08/11/2016] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS The metabolism of cytokinins (CKs) and auxins in vascular plants is relatively well understood, but data concerning their metabolic pathways in non-vascular plants are still rather rare. With the aim of filling this gap, 20 representatives of taxonomically major lineages of cyanobacteria and algae from Cyanophyceae, Xanthophyceae, Eustigmatophyceae, Porphyridiophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae, Zygnematophyceae and Klebsormidiophyceae were analysed for endogenous profiles of CKs and auxins and some of them were used for studies of the metabolic fate of exogenously applied radiolabelled CK, [3H]trans-zeatin (transZ) and auxin ([3H]indole-3-acetic acid (IAA)), and the dynamics of endogenous CK and auxin pools during algal growth and cell division. METHODS Quantification of phytohormone levels was performed by high-performance or ultrahigh-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-MS/MS, UHPLC-MS/MS). The dynamics of exogenously applied [3H]transZ and [3H]IAA in cell cultures were monitored by HPLC with on-line radioactivity detection. KEY RESULTS The comprehensive screen of selected cyanobacteria and algae for endogenous CKs revealed a predominance of bioactive and phosphate CK forms while O- and N-glucosides evidently did not contribute greatly to the total CK pool. The abundance of cis-zeatin-type CKs and occurrence of CK 2-methylthio derivatives pointed to the tRNA pathway as a substantial source of CKs. The importance of the tRNA biosynthetic pathway was proved by the detection of tRNA-bound CKs during the course of Scenedesmus obliquus growth. Among auxins, free IAA and its oxidation catabolite 2-oxindole-3-acetic acid represented the prevailing endogenous forms. After treatment with [3H]IAA, IAA-aspartate and indole-3-acetyl-1-glucosyl ester were detected as major auxin metabolites. Moreover, different dynamics of endogenous CKs and auxin profiles during S. obliquus culture clearly demonstrated diverse roles of both phytohormones in algal growth and cell division. CONCLUSIONS Our data suggest the existence and functioning of a complex network of metabolic pathways and activity control of CKs and auxins in cyanobacteria and algae that apparently differ from those in vascular plants.
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Affiliation(s)
- Eva Žižková
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany CAS, Rozvojová 263, CZ-165 02 Prague 6, Czech Republic
| | - Martin Kubeš
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany CAS, Rozvojová 263, CZ-165 02 Prague 6, Czech Republic
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic
| | - Petre I Dobrev
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany CAS, Rozvojová 263, CZ-165 02 Prague 6, Czech Republic
| | - Pavel Přibyl
- Centre for Phycology and Biorefinery Research Centre of Competence, Institute of Botany CAS, Dukelská 135, CZ-379 82 Třeboň, Czech Republic
| | - Jan Šimura
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic
| | - Lenka Zahajská
- Isotope Laboratory, Institute of Experimental Botany CAS, Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic
| | - Lenka Záveská Drábková
- Department of Taxonomy and Biosystematics, Institute of Botany CAS, Zámek 1, CZ-252 43 Průhonice, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University and Institute of Experimental Botany CAS, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic
| | - Václav Motyka
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany CAS, Rozvojová 263, CZ-165 02 Prague 6, Czech Republic
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Saini K, Markakis MN, Zdanio M, Balcerowicz DM, Beeckman T, De Veylder L, Prinsen E, Beemster GTS, Vissenberg K. Alteration in Auxin Homeostasis and Signaling by Overexpression Of PINOID Kinase Causes Leaf Growth Defects in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2017; 8:1009. [PMID: 28659952 PMCID: PMC5470171 DOI: 10.3389/fpls.2017.01009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 05/26/2017] [Indexed: 05/18/2023]
Abstract
In plants many developmental processes are regulated by auxin and its directional transport. PINOID (PID) kinase helps to regulate this transport by influencing polar recruitment of PIN efflux proteins on the cellular membranes. We investigated how altered auxin levels affect leaf growth in Arabidopsis thaliana. Arabidopsis mutants and transgenic plants with altered PID expression levels were used to study the effect on auxin distribution and leaf development. Single knockouts showed small pleiotropic growth defects. Contrastingly, several leaf phenotypes related to changes in auxin concentrations and transcriptional activity were observed in PID overexpression (PIDOE ) lines. Unlike in the knockout lines, the leaves of PIDOE lines showed an elevation in total indole-3-acetic acid (IAA). Accordingly, enhanced DR5-visualized auxin responses were detected, especially along the leaf margins. Kinematic analysis revealed that ectopic expression of PID negatively affects cell proliferation and expansion rates, yielding reduced cell numbers and small-sized cells in the PIDOE leaves. We used PIDOE lines as a tool to study auxin dose effects on leaf development and demonstrate that auxin, above a certain threshold, has a negative affect on leaf growth. RNA sequencing further showed how subtle PIDOE -related changes in auxin levels lead to transcriptional reprogramming of cellular processes.
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Affiliation(s)
- Kumud Saini
- Integrated Molecular Plant Physiology Research, University of AntwerpAntwerp, Belgium
| | - Marios N. Markakis
- Integrated Molecular Plant Physiology Research, University of AntwerpAntwerp, Belgium
- Faculty of Health and Medical SciencesCopenhagen, Denmark
| | - Malgorzata Zdanio
- Integrated Molecular Plant Physiology Research, University of AntwerpAntwerp, Belgium
| | - Daria M. Balcerowicz
- Integrated Molecular Plant Physiology Research, University of AntwerpAntwerp, Belgium
| | - Tom Beeckman
- Center for Plant Systems Biology, VIBGhent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent UniversityGhent, Belgium
| | | | - Els Prinsen
- Integrated Molecular Plant Physiology Research, University of AntwerpAntwerp, Belgium
| | - Gerrit T. S. Beemster
- Integrated Molecular Plant Physiology Research, University of AntwerpAntwerp, Belgium
| | - Kris Vissenberg
- Integrated Molecular Plant Physiology Research, University of AntwerpAntwerp, Belgium
- Plant Biochemistry and Biotechnology Lab, Department Of Agriculture, School of Agriculture, Food and Nutrition, University of Applied Sciences Crete – Technological Educational Institute (UASC-TEI)Heraklion, Greece
- *Correspondence: Kris Vissenberg, ;
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227
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Veloccia A, Fattorini L, Della Rovere F, Sofo A, D'Angeli S, Betti C, Falasca G, Altamura MM. Ethylene and auxin interaction in the control of adventitious rooting in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:6445-6458. [PMID: 27831474 PMCID: PMC5181586 DOI: 10.1093/jxb/erw415] [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] [Indexed: 05/21/2023]
Abstract
Adventitious roots (ARs) are post-embryonic roots essential for plant survival and propagation. Indole-3-acetic acid (IAA) is the auxin that controls AR formation; however, its precursor indole-3-butyric acid (IBA) is known to enhance it. Ethylene affects many auxin-dependent processes by affecting IAA synthesis, transport and/or signaling, but its role in AR formation has not been elucidated. This research investigated the role of ethylene in AR formation in dark-grown Arabidopsis thaliana seedlings, and its interaction with IAA/IBA. A number of mutants/transgenic lines were exposed to various treatments, and mRNA in situ hybridizations were carried out and hormones were quantified In the wild-type, the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) at 0.1 μM enhanced AR formation when combined with IBA (10 μM), but reduced it when applied alone; this effect did not occur in the ein3eil1 ethylene-insensitive mutant. ACC inhibited the expression of the IAA-biosynthetic genes WEI2, WEI7, and YUC6, but enhanced IBA-to-IAA conversion, as shown by the response of the ech2ibr10 mutant and an increase in the endogenous levels of IAA. The ethylene effect was independent of auxin-signaling by TIR1-AFB2 and IBA-efflux by ABCG carriers, but it was dependent on IAA-influx by AUX1/LAX3.Taken together, the results demonstrate that a crosstalk involving ethylene signaling, IAA-influx, and IBA-to-IAA conversion exists between ethylene and IAA in the control of AR formation.
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Affiliation(s)
- A Veloccia
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - L Fattorini
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - F Della Rovere
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - A Sofo
- School of Agricultural, Forestry, Food and Environmental Sciences (SAFE), Università degli Studi della Basilicata, Potenza, Italy
| | - S D'Angeli
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - C Betti
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium
| | - G Falasca
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
| | - M M Altamura
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy
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228
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Aremu AO, Plačková L, Pěnčík A, Novák O, Doležal K, Van Staden J. Auxin-cytokinin interaction and variations in their metabolic products in the regulation of organogenesis in two Eucomis species. N Biotechnol 2016; 33:883-890. [DOI: 10.1016/j.nbt.2016.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 07/12/2016] [Accepted: 09/03/2016] [Indexed: 01/31/2023]
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Arabidopsis thaliana GH3.5 acyl acid amido synthetase mediates metabolic crosstalk in auxin and salicylic acid homeostasis. Proc Natl Acad Sci U S A 2016; 113:13917-13922. [PMID: 27849615 DOI: 10.1073/pnas.1612635113] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In Arabidopsis thaliana, the acyl acid amido synthetase Gretchen Hagen 3.5 (AtGH3.5) conjugates both indole-3-acetic acid (IAA) and salicylic acid (SA) to modulate auxin and pathogen response pathways. To understand the molecular basis for the activity of AtGH3.5, we determined the X-ray crystal structure of the enzyme in complex with IAA and AMP. Biochemical analysis demonstrates that the substrate preference of AtGH3.5 is wider than originally described and includes the natural auxin phenylacetic acid (PAA) and the potential SA precursor benzoic acid (BA). Residues that determine IAA versus BA substrate preference were identified. The dual functionality of AtGH3.5 is unique to this enzyme although multiple IAA-conjugating GH3 proteins share nearly identical acyl acid binding sites. In planta analysis of IAA, PAA, SA, and BA and their respective aspartyl conjugates were determined in wild-type and overexpressing lines of A thaliana This study suggests that AtGH3.5 conjugates auxins (i.e., IAA and PAA) and benzoates (i.e., SA and BA) to mediate crosstalk between different metabolic pathways, broadening the potential roles for GH3 acyl acid amido synthetases in plants.
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230
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Functional roles of Arabidopsis CKRC2/YUCCA8 gene and the involvement of PIF4 in the regulation of auxin biosynthesis by cytokinin. Sci Rep 2016; 6:36866. [PMID: 27827441 PMCID: PMC5101810 DOI: 10.1038/srep36866] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 10/21/2016] [Indexed: 11/09/2022] Open
Abstract
Auxin and cytokinin (CK) are both important hormones involved in many aspects of plant growth and development. However, the details of auxin biosynthesis and the interaction between auxin and CK are still unclear. Isolation and characterization of an auxin deficient mutant cytokinin induced root curling 2 (ckrc2) in this work reveal that CKRC2 encodes a previously identified member of YUCCA (YUC) flavin monooxygenase-like proteins (YUC8). Our results show that, like other YUCs, CKRC2/YUC8 is a rate-limiting enzyme for catalyzing the conversion of indole-3-pyruvic acid (IPyA) to indole-3-acetic acid (IAA), acting downstream of CKRC1/TAA1 in the IPyA pathway. Here we show that the transcription of both CKRC1/TAA and CKRC2/YUC8 can be induced by CK and that the phytochrome-interacting factor 4 (PIF4) is required for this upregulation. Transcription of PIF4 itself is induced by CK via the AHKs-ARR1/12 signalling pathway. These results indicate that PIF4 plays an essential role in mediating the regulatory effect of CK on the transcriptions of CKRC1 and CKRC2 genes in the IPyA pathway of auxin biosynthesis.
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231
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Ciarkowska A, Ostrowski M, Jakubowska A. Abiotic stress and phytohormones affect enzymic activity of 1-O-(indole-3-acetyl)-β-d-glucose: myo-inositol indoleacetyl transferase from rice (Oryza sativa). JOURNAL OF PLANT PHYSIOLOGY 2016; 205:93-96. [PMID: 27649324 DOI: 10.1016/j.jplph.2016.07.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/19/2016] [Accepted: 07/19/2016] [Indexed: 05/27/2023]
Abstract
Indole-3-acetic acid (IAA) conjugation is a part of mechanism regulating free auxin concentration. 1-O-(indole-3-acetyl)-β-d-glucose: myo-inositol indoleacetyl transferase (IAInos synthase) is an enzyme involved in IAA-ester conjugates biosynthesis. Biotic and abiotic stress conditions can modulate auxin conjugates formation in plants. In this study, we investigated effect of plant hormones (IAA, ABA, SA and 2,4-D) and abiotic stress (drought and salt stress: 150mM NaCl and 300mM NaCl) on expression level and catalytic activity of rice IAInos synthase. Enzymic activity assay indicated that all tested phytohormones affected activity of IAInos synthase, but only ABA had inhibiting effect, while IAA, SA and 2,4-D activated the enzyme. Drought and salt stress induced with lower NaCl concentration resulted in decreased activity of IAInos synthase, but 300mM NaCl had no effect on the enzyme. Despite observed differences in enzymic activities, no changes of expression level, tested by semiquantitative RT-PCR and Western blot, were detected. Based on our results it has been supposed that plant hormones and stress conditions affect IAInos synthase activity on posttranslational level.
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Affiliation(s)
- Anna Ciarkowska
- Department of Biochemistry, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland.
| | - Maciej Ostrowski
- Department of Biochemistry, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland.
| | - Anna Jakubowska
- Department of Biochemistry, Nicolaus Copernicus University, Lwowska 1, 87-100 Torun, Poland.
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232
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Liu F, Zhang L, Luo Y, Xu M, Fan Y, Wang L. Interactions of Oryza sativa OsCONTINUOUS VASCULAR RING-LIKE 1 (OsCOLE1) and OsCOLE1-INTERACTING PROTEIN reveal a novel intracellular auxin transport mechanism. THE NEW PHYTOLOGIST 2016; 212:96-107. [PMID: 27265035 DOI: 10.1111/nph.14021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 04/16/2016] [Indexed: 06/05/2023]
Abstract
Little is known about the transport mechanism of intracellular auxin. Here, we report two vacuole-localized proteins, Oryza sativa OsCONTINUOUS VASCULAR RING-LIKE 1 (OsCOLE1) and OsCOLE1-INTERACTING PROTEIN (OsCLIP), that regulate intracellular auxin transport and homoeostasis. Overexpression of OsCOLE1 markedly increased the internode length and auxin content of the stem base, whereas these parameters were decreased in RNA interference (RNAi) plants. OsCOLE1 was localized on the tonoplast and preferentially expressed in mature tissues. We further identified its interacting protein OsCLIP, which was co-localized on the tonoplast. Protein-protein binding assays demonstrated that the N-terminus of OsCOLE1 directly interacted with OsCLIP in yeast cells and the rice protoplast. Furthermore, (3) H-indole-3-acetic acid ((3) H-IAA) transport assays revealed that OsCLIP transported IAA into yeast cells, which was promoted by OsCOLE1. The results indicate that OsCOLE1 affects rice development by regulating intracellular auxin transport through interaction with OsCLIP, which provides a new insight into the regulatory mechanism of intracellular transport of auxin and the roles of vacuoles in plant development.
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Affiliation(s)
- Fei Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, China
| | - Lan Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, China
| | - Yanzhong Luo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, China
| | - Miaoyun Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, China
| | - Yunliu Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, China
| | - Lei Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, China
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233
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Jásik J, Bokor B, Stuchlík S, Mičieta K, Turňa J, Schmelzer E. Effects of Auxins on PIN-FORMED2 (PIN2) Dynamics Are Not Mediated by Inhibiting PIN2 Endocytosis. PLANT PHYSIOLOGY 2016; 172:1019-1031. [PMID: 27506239 PMCID: PMC5047079 DOI: 10.1104/pp.16.00563] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/04/2016] [Indexed: 05/20/2023]
Abstract
By using the photoconvertible fluorescence protein Dendra2 as a tag we demonstrated that neither the naturally occurring auxins indole-3-acetic acid and indole-3-butyric acid, nor the synthetic auxin analogs 1-naphthaleneacetic acid and 2,4-dichlorophenoxyacetic acid nor compounds inhibiting polar auxin transport such as 2,3,5-triiodobenzoic acid and 1-N-naphthylphthalamic acid, were able to inhibit endocytosis of the putative auxin transporter PIN-FORMED2 (PIN2) in Arabidopsis (Arabidopsis thaliana) root epidermis cells. All compounds, except Indole-3-butyric acid, repressed the recovery of the PIN2-Dendra2 plasma membrane pool after photoconversion when they were used in high concentrations. The synthetic auxin analogs 1-naphthaleneacetic acid and 2,4-dichlorophenoxyacetic acid showed the strongest inhibition. Auxins and auxin transport inhibitors suppressed also the accumulation of both newly synthesized and endocytotic PIN2 pools in Brefeldin A compartments (BFACs). Furthermore, we demonstrated that all compounds are also interfering with BFAC formation. The synthetic auxin analogs caused the highest reduction in the number and size of BFACs. We concluded that auxins and inhibitors of auxin transport do affect PIN2 turnover in the cells, but it is through the synthetic rather than the endocytotic pathway. The study also confirmed inappropriateness of the BFA-based approach to study PIN2 endocytosis because the majority of PIN2 accumulating in BFACs is newly synthesized and not derived from the plasma membrane.
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Affiliation(s)
- Ján Jásik
- Comenius University Science Park, Comenius University, 841 04 Bratislava, Slovakia (J.J., B.B., S.S., K.M., J.T.); Institute of Botany, Slovak Academy of Sciences, 845 23 Bratislava (J.J.); Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, 842 15 Bratislava, Slovakia (S.S., J.T.); Department of Botany, Faculty of Natural Sciences, Comenius University, 811 02 Bratislava, Slovakia (K.M.); and Central Microscopy, Max Planck Institute for Plant Breeding Research, 508 29 Cologne, Germany (E.S.)
| | - Boris Bokor
- Comenius University Science Park, Comenius University, 841 04 Bratislava, Slovakia (J.J., B.B., S.S., K.M., J.T.); Institute of Botany, Slovak Academy of Sciences, 845 23 Bratislava (J.J.); Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, 842 15 Bratislava, Slovakia (S.S., J.T.); Department of Botany, Faculty of Natural Sciences, Comenius University, 811 02 Bratislava, Slovakia (K.M.); and Central Microscopy, Max Planck Institute for Plant Breeding Research, 508 29 Cologne, Germany (E.S.)
| | - Stanislav Stuchlík
- Comenius University Science Park, Comenius University, 841 04 Bratislava, Slovakia (J.J., B.B., S.S., K.M., J.T.); Institute of Botany, Slovak Academy of Sciences, 845 23 Bratislava (J.J.); Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, 842 15 Bratislava, Slovakia (S.S., J.T.); Department of Botany, Faculty of Natural Sciences, Comenius University, 811 02 Bratislava, Slovakia (K.M.); and Central Microscopy, Max Planck Institute for Plant Breeding Research, 508 29 Cologne, Germany (E.S.)
| | - Karol Mičieta
- Comenius University Science Park, Comenius University, 841 04 Bratislava, Slovakia (J.J., B.B., S.S., K.M., J.T.); Institute of Botany, Slovak Academy of Sciences, 845 23 Bratislava (J.J.); Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, 842 15 Bratislava, Slovakia (S.S., J.T.); Department of Botany, Faculty of Natural Sciences, Comenius University, 811 02 Bratislava, Slovakia (K.M.); and Central Microscopy, Max Planck Institute for Plant Breeding Research, 508 29 Cologne, Germany (E.S.)
| | - Ján Turňa
- Comenius University Science Park, Comenius University, 841 04 Bratislava, Slovakia (J.J., B.B., S.S., K.M., J.T.); Institute of Botany, Slovak Academy of Sciences, 845 23 Bratislava (J.J.); Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, 842 15 Bratislava, Slovakia (S.S., J.T.); Department of Botany, Faculty of Natural Sciences, Comenius University, 811 02 Bratislava, Slovakia (K.M.); and Central Microscopy, Max Planck Institute for Plant Breeding Research, 508 29 Cologne, Germany (E.S.)
| | - Elmon Schmelzer
- Comenius University Science Park, Comenius University, 841 04 Bratislava, Slovakia (J.J., B.B., S.S., K.M., J.T.); Institute of Botany, Slovak Academy of Sciences, 845 23 Bratislava (J.J.); Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, 842 15 Bratislava, Slovakia (S.S., J.T.); Department of Botany, Faculty of Natural Sciences, Comenius University, 811 02 Bratislava, Slovakia (K.M.); and Central Microscopy, Max Planck Institute for Plant Breeding Research, 508 29 Cologne, Germany (E.S.)
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Simm S, Scharf KD, Jegadeesan S, Chiusano ML, Firon N, Schleiff E. Survey of Genes Involved in Biosynthesis, Transport, and Signaling of Phytohormones with Focus on Solanum lycopersicum. Bioinform Biol Insights 2016; 10:185-207. [PMID: 27695302 PMCID: PMC5038615 DOI: 10.4137/bbi.s38425] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/15/2016] [Accepted: 08/16/2016] [Indexed: 12/19/2022] Open
Abstract
Phytohormones control the development and growth of plants, as well as their response to biotic and abiotic stress. The seven most well-studied phytohormone classes defined today are as follows: auxins, ethylene, cytokinin, abscisic acid, jasmonic acid, gibberellins, and brassinosteroids. The basic principle of hormone regulation is conserved in all plants, but recent results suggest adaptations of synthesis, transport, or signaling pathways to the architecture and growth environment of different plant species. Thus, we aimed to define the extent to which information from the model plant Arabidopsis thaliana is transferable to other plants such as Solanum lycopersicum. We extracted the co-orthologues of genes coding for major pathway enzymes in A. thaliana from the translated genomes of 12 species from the clade Viridiplantae. Based on predicted domain architecture and localization of the identified proteins from all 13 species, we inspected the conservation of phytohormone pathways. The comparison was complemented by expression analysis of (co-) orthologous genes in S. lycopersicum. Altogether, this information allowed the assignment of putative functional equivalents between A. thaliana and S. lycopersicum but also pointed to some variations between the pathways in eudicots, monocots, mosses, and green algae. These results provide first insights into the conservation of the various phytohormone pathways between the model system A. thaliana and crop plants such as tomato. We conclude that orthologue prediction in combination with analysis of functional domain architecture and intracellular localization and expression studies are sufficient tools to transfer information from model plants to other plant species. Our results support the notion that hormone synthesis, transport, and response for most part of the pathways are conserved, and species-specific variations can be found.
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Affiliation(s)
- Stefan Simm
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.; Cluster of Excellence Macromolecular Complexes, Institute for Molecular Cell Biology of Plants, Frankfurt am Main, Germany
| | - Klaus-Dieter Scharf
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.; Cluster of Excellence Macromolecular Complexes, Institute for Molecular Cell Biology of Plants, Frankfurt am Main, Germany
| | - Sridharan Jegadeesan
- Department of Vegetable Research, Institute for Plant Sciences, Agricultural Research Organization, Volcani Centre, Bet Dagan, Israel.; The Robert H. Smith Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Maria Luisa Chiusano
- Department of Soil, Plants Environmental and Animal Production Sciences, Laboratory of Computer Aided Biosciences, University of Studies of Naples Federico II, Portici, Naples, Italy
| | - Nurit Firon
- Department of Vegetable Research, Institute for Plant Sciences, Agricultural Research Organization, Volcani Centre, Bet Dagan, Israel
| | - Enrico Schleiff
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.; Cluster of Excellence Macromolecular Complexes, Institute for Molecular Cell Biology of Plants, Frankfurt am Main, Germany
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235
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DAO1 catalyzes temporal and tissue-specific oxidative inactivation of auxin in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2016; 113:11010-5. [PMID: 27651492 DOI: 10.1073/pnas.1604769113] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tight homeostatic regulation of the phytohormone auxin [indole-3-acetic acid (IAA)] is essential to plant growth. Auxin biosynthetic pathways and the processes that inactivate auxin by conjugation to amino acids and sugars have been thoroughly characterized. However, the enzyme that catalyzes oxidation of IAA to its primary catabolite 2-oxindole-3-acetic acid (oxIAA) remains uncharacterized. Here, we show that DIOXYGENASE FOR AUXIN OXIDATION 1 (DAO1) catalyzes formation of oxIAA in vitro and in vivo and that this mechanism regulates auxin homeostasis and plant growth. Null dao1-1 mutants contain 95% less oxIAA compared with wild type, and complementation of dao1 restores wild-type oxIAA levels, indicating that DAO1 is the primary IAA oxidase in seedlings. Furthermore, dao1 loss of function plants have altered morphology, including larger cotyledons, increased lateral root density, delayed sepal opening, elongated pistils, and reduced fertility in the primary inflorescence stem. These phenotypes are tightly correlated with DAO1 spatiotemporal expression patterns as shown by DAO1pro:β-glucuronidase (GUS) activity and DAO1pro:YFP-DAO1 signals, and transformation with DAO1pro:YFP-DAO1 complemented the mutant phenotypes. The dominant dao1-2D mutant has increased oxIAA levels and decreased stature with shorter leaves and inflorescence stems, thus supporting DAO1 IAA oxidase function in vivo. A second isoform, DAO2, is very weakly expressed in seedling root apices. Together, these data confirm that IAA oxidation by DAO1 is the principal auxin catabolic process in Arabidopsis and that localized IAA oxidation plays a role in plant morphogenesis.
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236
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Auxin catabolism unplugged: Role of IAA oxidation in auxin homeostasis. Proc Natl Acad Sci U S A 2016; 113:10742-4. [PMID: 27651487 DOI: 10.1073/pnas.1613506113] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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237
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Challa KR, Aggarwal P, Nath U. Activation of YUCCA5 by the Transcription Factor TCP4 Integrates Developmental and Environmental Signals to Promote Hypocotyl Elongation in Arabidopsis. THE PLANT CELL 2016; 28:2117-2130. [PMID: 27597774 PMCID: PMC5059803 DOI: 10.1105/tpc.16.00360] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 08/08/2016] [Accepted: 08/30/2016] [Indexed: 05/20/2023]
Abstract
Cell expansion is an essential process in plant morphogenesis and is regulated by the coordinated action of environmental stimuli and endogenous factors, such as the phytohormones auxin and brassinosteroid. Although the biosynthetic pathways that generate these hormones and their downstream signaling mechanisms have been extensively studied, the upstream transcriptional network that modulates their levels and connects their action to cell morphogenesis is less clear. Here, we show that the miR319-regulated TCP (TEOSINTE BRANCHED1, CYCLODEA, PROLIFERATING CELL FACTORS) transcription factors, notably TCP4, directly activate YUCCA5 transcription and integrate the auxin response to a brassinosteroid-dependent molecular circuit that promotes cell elongation in Arabidopsis thaliana hypocotyls. Furthermore, TCP4 modulates the common transcriptional network downstream to auxin-brassinosteroid signaling, which is also triggered by environmental cues, such as light, to promote cell expansion. Our study links TCP function with the hormone response during cell morphogenesis and shows that developmental and environmental signals converge on a common transcriptional network to promote cell elongation.
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Affiliation(s)
- Krishna Reddy Challa
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
| | - Pooja Aggarwal
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
| | - Utpal Nath
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
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238
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Yu R, Wang J, Xu L, Wang Y, Wang R, Zhu X, Sun X, Luo X, Xie Y, Everlyne M, Liu L. Transcriptome Profiling of Taproot Reveals Complex Regulatory Networks during Taproot Thickening in Radish (Raphanus sativus L.). FRONTIERS IN PLANT SCIENCE 2016; 7:1210. [PMID: 27597853 PMCID: PMC4992731 DOI: 10.3389/fpls.2016.01210] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 07/29/2016] [Indexed: 05/19/2023]
Abstract
Radish (Raphanus sativus L.) is one of the most important vegetable crops worldwide. Taproot thickening represents a critical developmental period that determines yield and quality in radish life cycle. To isolate differentially expressed genes (DGEs) involved in radish taproot thickening process and explore the molecular mechanism underlying taproot development, three cDNA libraries from radish taproot collected at pre-cortex splitting stage (L1), cortex splitting stage (L2), and expanding stage (L3) were constructed and sequenced by RNA-Seq technology. More than seven million clean reads were obtained from the three libraries, from which 4,717,617 (L1, 65.35%), 4,809,588 (L2, 68.24%) and 4,973,745 (L3, 69.45%) reads were matched to the radish reference genes, respectively. A total of 85,939 transcripts were generated from three libraries, from which 10,450, 12,325, and 7392 differentially expressed transcripts (DETs) were detected in L1 vs. L2, L1 vs. L3, and L2 vs. L3 comparisons, respectively. Gene Ontology and pathway analysis showed that many DEGs, including EXPA9, Cyclin, CaM, Syntaxin, MADS-box, SAUR, and CalS were involved in cell events, cell wall modification, regulation of plant hormone levels, signal transduction and metabolisms, which may relate to taproot thickening. Furthermore, the integrated analysis of mRNA-miRNA revealed that 43 miRNAs and 92 genes formed 114 miRNA-target mRNA pairs were co-expressed, and three miRNA-target regulatory networks of taproot were constructed from different libraries. Finally, the expression patterns of 16 selected genes were confirmed using RT-qPCR analysis. A hypothetical model of genetic regulatory network associated with taproot thickening in radish was put forward. The taproot formation of radish is mainly attributed to cell differentiation, division and expansion, which are regulated and promoted by certain specific signal transduction pathways and metabolism processes. These results could provide new insights into the complex molecular mechanism underlying taproot thickening and facilitate genetic improvement of taproot in radish.
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Affiliation(s)
- Rugang Yu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
- School of Life Science, Huaibei Normal UniversityHuaibei, China
| | - Jing Wang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Liang Xu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Yan Wang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Ronghua Wang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Xianwen Zhu
- Department of Plant Sciences, North Dakota State UniversityFargo, ND, USA
| | - Xiaochuan Sun
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Xiaobo Luo
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Yang Xie
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Muleke Everlyne
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Liwang Liu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural UniversityNanjing, China
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239
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Eyer L, Vain T, Pařízková B, Oklestkova J, Barbez E, Kozubíková H, Pospíšil T, Wierzbicka R, Kleine-Vehn J, Fránek M, Strnad M, Robert S, Novak O. 2,4-D and IAA Amino Acid Conjugates Show Distinct Metabolism in Arabidopsis. PLoS One 2016; 11:e0159269. [PMID: 27434212 PMCID: PMC4951038 DOI: 10.1371/journal.pone.0159269] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/29/2016] [Indexed: 11/19/2022] Open
Abstract
The herbicide 2,4-D exhibits an auxinic activity and therefore can be used as a synthetic and traceable analog to study auxin-related responses. Here we identified that not only exogenous 2,4-D but also its amide-linked metabolite 2,4-D-Glu displayed an inhibitory effect on plant growth via the TIR1/AFB auxin-mediated signaling pathway. To further investigate 2,4-D metabolite conversion, identity and activity, we have developed a novel purification procedure based on the combination of ion exchange and immuno-specific sorbents combined with a sensitive liquid chromatography-mass spectrometry method. In 2,4-D treated samples, 2,4-D-Glu and 2,4-D-Asp were detected at 100-fold lower concentrations compared to 2,4-D levels, showing that 2,4-D can be metabolized in the plant. Moreover, 2,4-D-Asp and 2,4-D-Glu were identified as reversible forms of 2,4-D homeostasis that can be converted to free 2,4-D. This work paves the way to new studies of auxin action in plant development.
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Affiliation(s)
- Luděk Eyer
- Department of Virology, Veterinary Research Institute, Brno, Czech Republic
| | - Thomas Vain
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Barbora Pařízková
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany CAS & Faculty of Science of Palacký University, Olomouc, Czech Republic
| | - Jana Oklestkova
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany CAS & Faculty of Science of Palacký University, Olomouc, Czech Republic
| | - Elke Barbez
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Hana Kozubíková
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University, Olomouc, Czech Republic
| | - Tomáš Pospíšil
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science of Palacký University, Olomouc, Czech Republic
| | - Roksana Wierzbicka
- Department of Virology, Veterinary Research Institute, Brno, Czech Republic
| | - Jürgen Kleine-Vehn
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Milan Fránek
- Department of Virology, Veterinary Research Institute, Brno, Czech Republic
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany CAS & Faculty of Science of Palacký University, Olomouc, Czech Republic
| | - Stéphanie Robert
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, Sweden
- * E-mail: (ON); (SR)
| | - Ondrej Novak
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany CAS & Faculty of Science of Palacký University, Olomouc, Czech Republic
- * E-mail: (ON); (SR)
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240
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Shigenaga AM, Argueso CT. No hormone to rule them all: Interactions of plant hormones during the responses of plants to pathogens. Semin Cell Dev Biol 2016; 56:174-189. [PMID: 27312082 DOI: 10.1016/j.semcdb.2016.06.005] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/01/2016] [Accepted: 06/07/2016] [Indexed: 11/17/2022]
Abstract
Plant hormones are essential regulators of plant growth and immunity. In the last few decades, a vast amount of information has been obtained detailing the role of different plant hormones in immunity, and how they work together to ultimately shape the outcomes of plant pathogen interactions. Here we provide an overview on the roles of the main classes of plant hormones in the regulation of plant immunity, highlighting their metabolic and signaling pathways and how plants and pathogens utilize these pathways to activate or suppress defence.
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Affiliation(s)
- Alexandra M Shigenaga
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, USA
| | - Cristiana T Argueso
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, USA.
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241
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Novák O, Pěnčík A, Blahoušek O, Ljung K. Quantitative Auxin Metabolite Profiling Using Stable Isotope Dilution UHPLC-MS/MS. ACTA ACUST UNITED AC 2016; 1:419-430. [DOI: 10.1002/cppb.20028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Ondřej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany CAS, Faculty of Science, Palacký University; Olomouc Czech Republic
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences; Umeå Sweden
| | - Aleš Pěnčík
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences; Umeå Sweden
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University; Olomouc Czech Republic
| | - Ota Blahoušek
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany CAS, Faculty of Science, Palacký University; Olomouc Czech Republic
| | - Karin Ljung
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences; Umeå Sweden
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242
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Arabidopsis Myrosinase Genes AtTGG4 and AtTGG5 Are Root-Tip Specific and Contribute to Auxin Biosynthesis and Root-Growth Regulation. Int J Mol Sci 2016; 17:ijms17060892. [PMID: 27338341 PMCID: PMC4926426 DOI: 10.3390/ijms17060892] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 05/31/2016] [Accepted: 06/02/2016] [Indexed: 11/17/2022] Open
Abstract
Plant myrosinases (β-thioglucoside glucohydrolases) are classified into two subclasses, Myr I and Myr II. The biological function of Myr I has been characterized as a major biochemical defense against insect pests and pathogens in cruciferous plants. However, the biological function of Myr II remains obscure. We studied the function of two Myr II member genes AtTGG4 and AtTGG5 in Arabidopsis. RT-PCR showed that both genes were specifically expressed in roots. GUS-assay revealed that both genes were expressed in the root-tip but with difference: AtTGG4 was expressed in the elongation zone of the root-tip, while AtTGG5 was expressed in the whole root-tip. Moreover, myrosin cells that produce and store the Myr I myrosinases in aboveground organs were not observed in roots, and AtTGG4 and AtTGG5 were expressed in all cells of the specific region. A homozygous double mutant line tgg4tgg5 was obtained through cross-pollination between two T-DNA insertion lines, tgg4E8 and tgg5E12, by PCR-screening in the F2 and F3 generations. Analysis of myrosinase activity in roots of mutants revealed that AtTGG4 and AtTGG5 had additive effects and contributed 35% and 65% myrosinase activity in roots of the wild type Col-0, respectively, and myrosinase activity in tgg4tgg5 was severely repressed. When grown in Murashiege & Skoog (MS) medium or in soil with sufficient water, Col-0 had the shortest roots, and tgg4tgg5 had the longest roots, while tgg4E8 and tgg5E12 had intermediate root lengths. In contrast, when grown in soil with excessive water, Col-0 had the longest roots, and tgg4tgg5 had the shortest roots. These results suggested that AtTGG4 and AtTGG5 regulated root growth and had a role in flood tolerance. The auxin-indicator gene DR5::GUS was then introduced into tgg4tgg5 by cross-pollination. DR5::GUS expression patterns in seedlings of F1, F2, and F3 generations indicated that AtTGG4 and AtTGG5 contributed to auxin biosynthesis in roots. The proposed mechanism is that indolic glucosinolate is transported to the root-tip and converted to indole-3-acetonitrile (IAN) in the tryptophan-dependent pathways by AtTGG4 and AtTGG5, and IAN is finally converted to indole-3-acetic acid (IAA) by nitrilases in the root-tip. This mechanism guarantees the biosynthesis of IAA in correct cells of the root-tip and, thus, a correct auxin gradient is formed for healthy development of roots.
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243
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Schühle K, Nies J, Heider J. An indoleacetate-CoA ligase and a phenylsuccinyl-CoA transferase involved in anaerobic metabolism of auxin. Environ Microbiol 2016; 18:3120-32. [DOI: 10.1111/1462-2920.13347] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/15/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Karola Schühle
- Laboratory for Microbiology; Philipps-Universität Marburg; Karl-von-Frisch-Straße 8 35043 Marburg Germany
| | - Jonas Nies
- Laboratory for Microbiology; Philipps-Universität Marburg; Karl-von-Frisch-Straße 8 35043 Marburg Germany
| | - Johann Heider
- Laboratory for Microbiology; Philipps-Universität Marburg; Karl-von-Frisch-Straße 8 35043 Marburg Germany
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244
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Gangola MP, Jaiswal S, Kannan U, Gaur PM, Båga M, Chibbar RN. Galactinol synthase enzyme activity influences raffinose family oligosaccharides (RFO) accumulation in developing chickpea (Cicer arietinum L.) seeds. PHYTOCHEMISTRY 2016; 125:88-98. [PMID: 26953100 DOI: 10.1016/j.phytochem.2016.02.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 02/10/2016] [Accepted: 02/18/2016] [Indexed: 06/05/2023]
Abstract
To understand raffinose family oligosaccharides (RFO) metabolism in chickpea (Cicer arietinum L.) seeds, RFO accumulation and corresponding biosynthetic enzymes activities were determined during seed development of chickpea genotypes with contrasting RFO concentrations. RFO concentration in mature seeds was found as a facilitator rather than a regulating step of seed germination. In mature seeds, raffinose concentrations ranged from 0.38 to 0.68 and 0.75 to 0.99 g/100 g, whereas stachyose concentrations varied from 0.79 to 1.26 and 1.70 to 1.87 g/100 g indicating significant differences between low and high RFO genotypes, respectively. Chickpea genotypes with high RFO concentration accumulated higher concentrations of myo-inositol and sucrose during early seed developmental stages suggesting that initial substrate concentrations may influence RFO concentration in mature seeds. High RFO genotypes showed about two to three-fold higher activity for all RFO biosynthetic enzymes compared to those with low RFO concentrations. RFO biosynthetic enzymes activities correspond with accumulation of individual RFO during seed development.
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Affiliation(s)
- Manu P Gangola
- Department of Plant Sciences, College of Agriculture and Bioresources, 51 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada
| | - Sarita Jaiswal
- Department of Plant Sciences, College of Agriculture and Bioresources, 51 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada
| | - Udhaya Kannan
- Department of Plant Sciences, College of Agriculture and Bioresources, 51 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada
| | - Pooran M Gaur
- International Crops Research Institute for the Semi-Arid-Tropics, Patancheru near Hyderabad, Telangana, India
| | - Monica Båga
- Department of Plant Sciences, College of Agriculture and Bioresources, 51 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada
| | - Ravindra N Chibbar
- Department of Plant Sciences, College of Agriculture and Bioresources, 51 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada.
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245
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Zheng Z, Guo Y, Novák O, Chen W, Ljung K, Noel JP, Chory J. Local auxin metabolism regulates environment-induced hypocotyl elongation. NATURE PLANTS 2016; 2:16025. [PMID: 27249562 PMCID: PMC4849989 DOI: 10.1038/nplants.2016.25] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/12/2016] [Indexed: 05/18/2023]
Abstract
A hallmark of plants is their adaptability of size and form in response to widely fluctuating environments. The metabolism and redistribution of the phytohormone auxin play pivotal roles in establishing active auxin gradients and resulting cellular differentiation. In Arabidopsis thaliana, cotyledons and leaves synthesize indole-3-acetic acid (IAA) from tryptophan through indole-3-pyruvic acid (3-IPA) in response to vegetational shade. This newly synthesized auxin moves to the hypocotyl where it induces elongation of hypocotyl cells. Here we show that loss of function of VAS2 (IAA-amido synthetase Gretchen Hagen 3 (GH3).17) leads to increases in free IAA at the expense of IAA-Glu (IAA-glutamate) in the hypocotyl epidermis. This active IAA elicits shade- and high temperature-induced hypocotyl elongation largely independently of 3-IPA-mediated IAA biosynthesis in cotyledons. Our results reveal an unexpected capacity of local auxin metabolism to modulate the homeostasis and spatial distribution of free auxin in specialized organs such as hypocotyls in response to shade and high temperature.
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Affiliation(s)
- Zuyu Zheng
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Yongxia Guo
- The Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Ondřej Novák
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany ASCR, Šlechtielů 11, 783 71 Olomouc, Czech Republic
| | - William Chen
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Karin Ljung
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Joseph P. Noel
- Howard Hughes Medical Institute and The Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, California 92037, USA, Czech Republic
- Correspondence and requests for materials should be addressed to J.P.N. and J.C. ;
| | - Joanne Chory
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
- Correspondence and requests for materials should be addressed to J.P.N. and J.C. ;
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246
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Different cucumber CsYUC genes regulate response to abiotic stresses and flower development. Sci Rep 2016; 6:20760. [PMID: 26857463 PMCID: PMC4746583 DOI: 10.1038/srep20760] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/07/2016] [Indexed: 12/22/2022] Open
Abstract
The phytohormone auxin is essential for plant growth and development, and YUCCA (YUC) proteins catalyze a rate-limiting step for endogenous auxin biosynthesis. Despite YUC family genes have been isolated from several species, systematic expression analyses of YUCs in response to abiotic stress are lacking, and little is known about the function of YUC homologs in agricultural crops. Cucumber (Cucumis sativus L.) is a world cultivated vegetable crop with great economical and nutritional value. In this study, we isolated 10 YUC family genes (CsYUCs) from cucumber and explored their expression pattern under four types of stress treatments. Our data showed that CsYUC8 and CsYUC9 were specifically upregulated to elevate the auxin level under high temperature. CsYUC10b was dramatically increased but CsYUC4 was repressed in response to low temperature. CsYUC10a and CsYUC11 act against the upregulation of CsYUC10b under salinity stress, suggesting that distinct YUC members participate in different stress response, and may even antagonize each other to maintain the proper auxin levels in cucumber. Further, CsYUC11 was specifically expressed in the male flower in cucumber, and enhanced tolerance to salinity stress and regulated pedicel and stamen development through auxin biosynthesis in Arabidopsis.
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Lulai EC, Suttle JC, Olson LL, Neubauer JD, Campbell LG, Campbell MA. Wounding induces changes in cytokinin and auxin content in potato tuber, but does not induce formation of gibberellins. JOURNAL OF PLANT PHYSIOLOGY 2016; 191:22-28. [PMID: 26708026 DOI: 10.1016/j.jplph.2015.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 11/17/2015] [Accepted: 11/18/2015] [Indexed: 06/05/2023]
Abstract
Cytokinin, auxin and gibberellin contents in resting and wound-responding potato tubers have not been fully determined and coordinated with wound-healing processes. Using a well-defined wound-healing model system, hormone content and expression of genes associated with hormone turnover were determined in tubers following wounding. Changes in hormone content were coordinated with: (I) formation and completion of the wound closing layer (0-5/6 days), and (II) initiation of phellogen and wound periderm formation (∼ 7 days). Quantifiable amounts of biologically active cytokinins (Z, DZ and IP) were not detected in resting or wound-responding tubers. However, the precursor IPA and catabolic product c-ZOG were found in small amounts in resting and wound-responding tubers. Wound-induced activation of cytokinin biosynthesis was suggested by an increase in t-ZR and c-ZR content at 0.5 days and large increases in IPA and c-ZR content by 3 days and throughout 7 days after wounding suggesting roles in II, but little or no role in I. Expression of key genes involved in cytokinin metabolism followed similar profiles with transcripts decreasing through 3 days and then increasing at 5-7 days after wounding. Both free IAA and IAA-Asp were present in resting tubers. While IAA-Asp was no longer present by 3 days after wounding, IAA content nearly doubled by 5 days and was more than 4-fold greater at 7 days compared to that in resting tuber (0 day) suggesting roles in II, but little or no role in I. Gibberellins were not present in quantifiable amounts in resting or wound-responding tubers. These results suggest that bio-active cytokinins are wound-induced, but their residency is temporal and highly regulated. The transient presence of active cytokinins and corresponding increases in IAA content strongly suggest their involvement in the regulation of wound periderm development. The absence of gibberellins indicates that they are not a regulatory component of wound-healing processes.
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Affiliation(s)
- Edward C Lulai
- United States Department of Agriculture, Agricultural Research Service, Sugarbeet and Potato Unit, Northern Crop Science Laboratory, Fargo, ND 58102-2765, United States.
| | - Jeffrey C Suttle
- United States Department of Agriculture, Agricultural Research Service, Sugarbeet and Potato Unit, Northern Crop Science Laboratory, Fargo, ND 58102-2765, United States
| | - Linda L Olson
- United States Department of Agriculture, Agricultural Research Service, Sugarbeet and Potato Unit, Northern Crop Science Laboratory, Fargo, ND 58102-2765, United States
| | - Jonathan D Neubauer
- United States Department of Agriculture, Agricultural Research Service, Sugarbeet and Potato Unit, Northern Crop Science Laboratory, Fargo, ND 58102-2765, United States
| | - Larry G Campbell
- United States Department of Agriculture, Agricultural Research Service, Sugarbeet and Potato Unit, Northern Crop Science Laboratory, Fargo, ND 58102-2765, United States
| | - Michael A Campbell
- School of Science, Penn State Erie, The Behrend College, P-1 Prischak Building, 4205 College Drive, Erie, PA 16563-0203, United States
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248
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Kuhn BM, Errafi S, Bucher R, Dobrev P, Geisler M, Bigler L, Zažímalová E, Ringli C. 7-Rhamnosylated Flavonols Modulate Homeostasis of the Plant Hormone Auxin and Affect Plant Development. J Biol Chem 2016; 291:5385-95. [PMID: 26742840 DOI: 10.1074/jbc.m115.701565] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Indexed: 11/06/2022] Open
Abstract
Flavonols are a group of secondary metabolites that affect diverse cellular processes. They are considered putative negative regulators of the transport of the phytohormone auxin, by which they influence auxin distribution and concomitantly take part in the control of plant organ development. Flavonols are accumulating in a large number of glycosidic forms. Whether these have distinct functions and diverse cellular targets is not well understood. The rol1-2 mutant of Arabidopsis thaliana is characterized by a modified flavonol glycosylation profile that is inducing changes in auxin transport and growth defects in shoot tissues. To determine whether specific flavonol glycosides are responsible for these phenotypes, a suppressor screen was performed on the rol1-2 mutant, resulting in the identification of an allelic series of UGT89C1, a gene encoding a flavonol 7-O-rhamnosyltransferase. A detailed analysis revealed that interfering with flavonol rhamnosylation increases the concentration of auxin precursors and auxin metabolites, whereas auxin transport is not affected. This finding provides an additional level of complexity to the possible ways by which flavonols influence auxin distribution and suggests that flavonol glycosides play an important role in regulating plant development.
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Affiliation(s)
- Benjamin M Kuhn
- From the Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland
| | - Sanae Errafi
- From the Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland
| | - Rahel Bucher
- the Department of Chemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Petre Dobrev
- the Institute of Experimental Botany, Academy of Sciences of the Czech Republic, 165 02 Prague 6, Czech Republic, and
| | - Markus Geisler
- the Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Laurent Bigler
- the Department of Chemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Eva Zažímalová
- the Institute of Experimental Botany, Academy of Sciences of the Czech Republic, 165 02 Prague 6, Czech Republic, and
| | - Christoph Ringli
- From the Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland,
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249
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Zhang GZ, Jin SH, Jiang XY, Dong RR, Li P, Li YJ, Hou BK. Ectopic expression of UGT75D1, a glycosyltransferase preferring indole-3-butyric acid, modulates cotyledon development and stress tolerance in seed germination of Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2016; 90:77-93. [PMID: 26496910 DOI: 10.1007/s11103-015-0395-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 10/19/2015] [Indexed: 05/06/2023]
Abstract
The formation of auxin glucose conjugate is proposed to be one of the molecular modifications controlling auxin homeostasis. However, the involved mechanisms and relevant physiological significances are largely unknown or poorly understood. In this study, Arabidopsis UGT75D1 was at the first time identified to be an indole-3-butyric acid (IBA) preferring glycosyltransferase. Assessment of enzyme activity and IBA conjugates in transgenic plants ectopically expressing UGT75D1 indicated that the UGT75D1 catalytic specificity was maintained in planta. It was found that the expression pattern of UGT75D1 was specific in germinating seeds. Consistently, we found that transgenic seedlings with over-produced UGT75D1 exhibited smaller cotyledons and cotyledon epidermal cells than the wild type. In addition, UGT75D1 was found to be up-regulated under mannitol, salt and ABA treatments and the over-expression lines were tolerant to osmotic and salt stresses during germination, resulting in an increased germination rate. Quantitative RT-PCR analysis revealed that the mRNA levels of ABA INSENSITIVE 3 (ABI3) and ABI5 gene in ABA signaling were substantially down-regulated in the transgenic lines under stress treatments. Interestingly, AUXIN RESPONSE FACTOR 16 (ARF16) gene of transgenic lines was also dramatically down-regulated under the same stress conditions. Since ARF16 functions as an activator of ABI3 transcription, we supposed that UGT75D1 might play a role in stress tolerance during germination through modulating ARF16-ABI3 signaling. Taken together, our work indicated that, serving as the IBA preferring glycosyltransferase but distinct from other auxin glycosyltransferases identified so far, UGT75D1 might be a very important player mediating a crosstalk between cotyledon development and stress tolerance of germination at the early stage of plant growth.
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Affiliation(s)
- Gui-Zhi Zhang
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Chinese Ministry of Education; School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Shang-Hui Jin
- School of Life Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xiao-Yi Jiang
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Chinese Ministry of Education; School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Rui-Rui Dong
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Chinese Ministry of Education; School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Pan Li
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Chinese Ministry of Education; School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Yan-Jie Li
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Chinese Ministry of Education; School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Bing-Kai Hou
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Chinese Ministry of Education; School of Life Sciences, Shandong University, Jinan, 250100, China.
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250
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Pan L, Zeng W, Niu L, Lu Z, Liu H, Cui G, Zhu Y, Chu J, Li W, Fang W, Cai Z, Li G, Wang Z. PpYUC11, a strong candidate gene for the stony hard phenotype in peach (Prunus persica L. Batsch), participates in IAA biosynthesis during fruit ripening. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:7031-44. [PMID: 26307136 PMCID: PMC4765781 DOI: 10.1093/jxb/erv400] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
High concentrations of indole-3-acetic acid (IAA) are required for climacteric ethylene biosynthesis to cause fruit softening in melting flesh peaches at the late ripening stage. By contrast, the fruits of stony hard peach cultivars do not soften and produce little ethylene due to the low IAA concentrations. To investigate the regulation of IAA accumulation during peach ripening [the transition from stage S3 to stage S4 III (climacteric)], a digital gene expression (DGE) analysis was performed. The expression patterns of auxin-homeostasis-related genes were compared in fruits of the melting flesh peach 'Goldhoney 3' and the stony hard flesh peach 'Yumyeong' during the ripening stage. It is revealed here that a YUCCA flavin mono-oxygenase gene (PpYUC11, ppa008176m), a key gene in auxin biosynthesis, displayed an identical differential expression profile to the profiles of IAA accumulation and PpACS1 transcription: the mRNA transcripts increased at the late ripening stage in melting flesh peaches but were below the limit of detection in mature fruits of stony hard peaches. In addition, the strong association between intron TC microsatellite genotypes of PpYUC11 and the flesh texture (normal or stony hard) is described in 43 peach varieties, indicating that this locus may be responsible for the stony hard phenotype in peach. These findings support the hypothesis that PpYUC11 may play an essential role in auxin biosynthesis during peach fruit ripening and is a candidate gene for the control of the stony hard phenotype in peach.
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Affiliation(s)
- Lei Pan
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenfang Zeng
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Liang Niu
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Zhenhua Lu
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Hui Liu
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Guochao Cui
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Yunqin Zhu
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Jinfang Chu
- National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weiping Li
- National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weichao Fang
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Zuguo Cai
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
| | - Guohuai Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhiqiang Wang
- Key Laboratory of Fruit Breeding Technology, Ministry of Agriculture, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
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