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Han Y, Qu M, Liu Z, Kang C. Transcription factor FveMYB117a inhibits axillary bud outgrowth by regulating cytokinin homeostasis in woodland strawberry. THE PLANT CELL 2024; 36:2427-2446. [PMID: 38547429 PMCID: PMC11132891 DOI: 10.1093/plcell/koae097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 03/11/2024] [Indexed: 05/30/2024]
Abstract
Shoot branching affects plant architecture. In strawberry (Fragaria L.), short branches (crowns) develop from dormant axillary buds to form inflorescences and flowers. While this developmental transition contributes greatly to perenniality and yield in strawberry, its regulatory mechanism remains unclear and understudied. In the woodland strawberry (Fragaria vesca), we identified and characterized 2 independent mutants showing more crowns. Both mutant alleles reside in FveMYB117a, a R2R3-MYB transcription factor gene highly expressed in shoot apical meristems, axillary buds, and young leaves. Transcriptome analysis revealed that the expression of several cytokinin pathway genes was altered in the fvemyb117a mutant. Consistently, active cytokinins were significantly increased in the axillary buds of the fvemyb117a mutant. Exogenous application of cytokinin enhanced crown outgrowth in the wild type, whereas the cytokinin inhibitors suppressed crown outgrowth in the fvemyb117a mutant. FveMYB117a binds directly to the promoters of the cytokinin homeostasis genes FveIPT2 encoding an isopentenyltransferase and FveCKX1 encoding a cytokinin oxidase to regulate their expression. Conversely, the type-B Arabidopsis response regulators FveARR1 and FveARR2b can directly inhibit the expression of FveMYB117a, indicative of a negative feedback regulation. In conclusion, we identified FveMYB117a as a key repressor of crown outgrowth by inhibiting cytokinin accumulation and provide a mechanistic basis for bud fate transition in an herbaceous perennial plant.
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Affiliation(s)
- Yafan Han
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Minghao Qu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Zhongchi Liu
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Chunying Kang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
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2
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Argueso CT, Kieber JJ. Cytokinin: From autoclaved DNA to two-component signaling. THE PLANT CELL 2024; 36:1429-1450. [PMID: 38163638 PMCID: PMC11062471 DOI: 10.1093/plcell/koad327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 01/03/2024]
Abstract
Since its first identification in the 1950s as a regulator of cell division, cytokinin has been linked to many physiological processes in plants, spanning growth and development and various responses to the environment. Studies from the last two and one-half decades have revealed the pathways underlying the biosynthesis and metabolism of cytokinin and have elucidated the mechanisms of its perception and signaling, which reflects an ancient signaling system evolved from two-component elements in bacteria. Mutants in the genes encoding elements involved in these processes have helped refine our understanding of cytokinin functions in plants. Further, recent advances have provided insight into the mechanisms of intracellular and long-distance cytokinin transport and the identification of several proteins that operate downstream of cytokinin signaling. Here, we review these processes through a historical lens, providing an overview of cytokinin metabolism, transport, signaling, and functions in higher plants.
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Affiliation(s)
- Cristiana T Argueso
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Joseph J Kieber
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
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3
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Kaeser G, Krauß N, Roughan C, Sauthof L, Scheerer P, Lamparter T. Phytochrome-Interacting Proteins. Biomolecules 2023; 14:9. [PMID: 38275750 PMCID: PMC10813442 DOI: 10.3390/biom14010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
Phytochromes are photoreceptors of plants, fungi, slime molds bacteria and heterokonts. These biliproteins sense red and far-red light and undergo light-induced changes between the two spectral forms, Pr and Pfr. Photoconversion triggered by light induces conformational changes in the bilin chromophore around the ring C-D-connecting methine bridge and is followed by conformational changes in the protein. For plant phytochromes, multiple phytochrome interacting proteins that mediate signal transduction, nuclear translocation or protein degradation have been identified. Few interacting proteins are known as bacterial or fungal phytochromes. Here, we describe how the interacting partners were identified, what is known about the different interactions and in which context of signal transduction these interactions are to be seen. The three-dimensional arrangement of these interacting partners is not known. Using an artificial intelligence system-based modeling software, a few predicted and modulated examples of interactions of bacterial phytochromes with their interaction partners are interpreted.
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Affiliation(s)
- Gero Kaeser
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
| | - Norbert Krauß
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
| | - Clare Roughan
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
| | - Luisa Sauthof
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Group Structural Biology of Cellular Signaling, Charitéplatz 1, D-10117 Berlin, Germany; (L.S.); (P.S.)
| | - Patrick Scheerer
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Group Structural Biology of Cellular Signaling, Charitéplatz 1, D-10117 Berlin, Germany; (L.S.); (P.S.)
| | - Tilman Lamparter
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
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4
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Hong L, Fletcher JC. Stem Cells: Engines of Plant Growth and Development. Int J Mol Sci 2023; 24:14889. [PMID: 37834339 PMCID: PMC10573764 DOI: 10.3390/ijms241914889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 09/30/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
The development of both animals and plants relies on populations of pluripotent stem cells that provide the cellular raw materials for organ and tissue formation. Plant stem cell reservoirs are housed at the shoot and root tips in structures called meristems, with the shoot apical meristem (SAM) continuously producing aerial leaf, stem, and flower organs throughout the life cycle. Thus, the SAM acts as the engine of plant development and has unique structural and molecular features that allow it to balance self-renewal with differentiation and act as a constant source of new cells for organogenesis while simultaneously maintaining a stem cell reservoir for future organ formation. Studies have identified key roles for intercellular regulatory networks that establish and maintain meristem activity, including the KNOX transcription factor pathway and the CLV-WUS stem cell feedback loop. In addition, the plant hormones cytokinin and auxin act through their downstream signaling pathways in the SAM to integrate stem cell activity and organ initiation. This review discusses how the various regulatory pathways collectively orchestrate SAM function and touches on how their manipulation can alter stem cell activity to improve crop yield.
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Affiliation(s)
- Liu Hong
- Plant Gene Expression Center, United States Department of Agriculture—Agricultural Research Service, Albany, CA 94710, USA;
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jennifer C. Fletcher
- Plant Gene Expression Center, United States Department of Agriculture—Agricultural Research Service, Albany, CA 94710, USA;
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
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5
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Chun Y, Kumar A, Li X. Genetic and molecular pathways controlling rice inflorescence architecture. FRONTIERS IN PLANT SCIENCE 2022; 13:1010138. [PMID: 36247571 PMCID: PMC9554555 DOI: 10.3389/fpls.2022.1010138] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Rice inflorescence is one of the major organs in determining grain yield. The genetic and molecular regulation on rice inflorescence architecture has been well investigated over the past years. In the present review, we described genes regulating rice inflorescence architecture based on their roles in meristem activity maintenance, meristem identity conversion and branch elongation. We also introduced the emerging regulatory pathways of phytohormones involved in rice inflorescence development. These studies show the intricacies and challenges of manipulating inflorescence architecture for rice yield improvement.
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Affiliation(s)
- Yan Chun
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ashmit Kumar
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Agriculture, Fisheries and Forestry, Fiji National University, Nausori, Fiji
| | - Xueyong Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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6
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Zha M, Zhao Y, Wang Y, Chen B, Tan Z. Strigolactones and Cytokinin Interaction in Buds in the Control of Rice Tillering. FRONTIERS IN PLANT SCIENCE 2022; 13:837136. [PMID: 35845690 PMCID: PMC9286680 DOI: 10.3389/fpls.2022.837136] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Shoot branching is among the most crucial morphological traits in rice (Oryza sativa L.) and is physiologically modulated by auxins, cytokinins (CKs), and strigolactones (SLs) cumulatively in rice. A number of studies focused on the interplay of these three hormones in regulating rice tiller extension. The present study primarily aimed at determining the impact of different treatments, which were used to regulate rice tiller and axillary bud development on node 2 at the tillering stage and full heading stage, respectively. Transcription levels of several genes were quantified through qRT-PCR analysis, and an endogenous auxin and four types of CKs were determined through LC-MS/MS. Both nutrient deficiency and exogenous SL supply were found to inhibit rice tiller outgrowth by reducing the CK content in the tiller buds. Furthermore, supplying the inhibitor of both exogenous SLs and endogenous SL synthesis could also affect the expression level of OsCKX genes but not the OsIPT genes. Comparison of OsCKX gene expression pattern under exogenous SL and CK supply suggested that the induction of OsCKX expression was most likely via a CK-induced independent pathway. These results combined with the expression of CK type-A RR genes in bud support a role for SLs in regulating bud outgrowth through the regulation of local CK levels. SL functioned antagonistically with CK in regulating the outgrowth of buds on node 2, by promoting the OsCKX gene expression in buds.
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Affiliation(s)
- Manrong Zha
- College of Biology Resources and Environmental Sciences, Jishou University, Jishou, China
- Key Laboratory of Plant Resources Conservation and Utilization, College of Hunan Province, Jishou, China
| | - Yanhui Zhao
- College of Biology Resources and Environmental Sciences, Jishou University, Jishou, China
- Key Laboratory of Plant Resources Conservation and Utilization, College of Hunan Province, Jishou, China
| | - Yan Wang
- College of Biology Resources and Environmental Sciences, Jishou University, Jishou, China
- Key Laboratory of Plant Resources Conservation and Utilization, College of Hunan Province, Jishou, China
| | - Bingxian Chen
- Guangdong Key Lab for Crop Germplasm Resources Preservation and Utilization, Guangzhou, China
| | - Zecheng Tan
- College of Biology Resources and Environmental Sciences, Jishou University, Jishou, China
- Key Laboratory of Plant Resources Conservation and Utilization, College of Hunan Province, Jishou, China
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7
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Rehman OU, Uzair M, Chao H, Fiaz S, Khan MR, Chen M. Role of the type-B authentic response regulator gene family in fragrant rice under alkaline salt stress. PHYSIOLOGIA PLANTARUM 2022; 174:e13696. [PMID: 35502736 DOI: 10.1111/ppl.13696] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 06/14/2023]
Abstract
Globally, rice is being consumed as a main staple food and faces different kinds of biotic and abiotic stresses such drought, salinity, and pest attacks. Through the cytokinin signaling, Type-B authentic response regulators (ARR-Bs) respond positively towards the environmental stimuli. ARR-Bs are involved in abiotic stress tolerance and plant development but their molecular mechanisms in fragrant rice are still not fully explored. The current study showed the genome-wide characterization of OsARR-B genes under alkaline salt stress. Results showed that in total, 24 OsARR-B genes were found and divided into four subgroups on the basis of a phylogenetic analysis. These genes were located on all rice chromosomes except 8 and 10. Analysis of gene duplications, gene structure, cis-elements, protein-protein interactions, and miRNA were performed. Gene ontology analysis showed that OsARR-B genes are involved in plant development through the regulation of molecular functions, biological processes, and cellular components. Furthermore, 117 and 192 RNA editing sites were detected in chloroplast and mitochondrial genes, respectively, encoding proteins of OsARR-B. In chloroplast and mitochondrial genes, six and nine types of amino acid changes, respectively, were caused by RNA editing, showing that RNA editing has a role in the alkaline salt stress tolerance in fragrant rice. We also used a comparative transcriptome approach to study the gene expression changes in alkaline tolerant and susceptible genotypes. Under alkaline salt stress, OsARR-B5, OsARR-B7, OsARR-B9, OsARR-B10, OsARR-B16, OsARR-B22, and OsARR-B23 showed higher transcript levels in alkaline salt tolerant genotypes as compared to susceptible ones. Quantitative RT-PCR showed upregulation of gene expression in the alkaline tolerant genotypes under alkaline stress. Our study explored the gene expression profiling and RESs of two rice contrasting genotypes, which will help to understand the molecular mechanisms of alkaline salt tolerance in fragrant rice.
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Affiliation(s)
- Obaid Ur Rehman
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
- National Institute for Genomics and Advanced Biotechnology, Islamabad, Pakistan
| | - Muhammad Uzair
- National Institute for Genomics and Advanced Biotechnology, Islamabad, Pakistan
| | - Haoyu Chao
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Sajid Fiaz
- Department of Plant Breeding and Genetics, The University of Haripur, Haripur, Pakistan
| | | | - Ming Chen
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
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8
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Li J, Li D, Liu B, Wang R, Yan Y, Li G, Wang L, Ma C, Xu W, Zhao L, Li X, Wang S. Effects of root restriction on phytohormone levels in different growth stages and grapevine organs. Sci Rep 2022; 12:1323. [PMID: 35079016 PMCID: PMC8789776 DOI: 10.1038/s41598-021-04617-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 12/28/2021] [Indexed: 11/10/2022] Open
Abstract
Phytohormones play important roles in germination, blossom, senescence, abscission of plants by a series of signal transduction and molecular regulation. The purpose of this research was to investigate the influence of root restriction (RR) cultivation on plant endogenous hormone variation tendency at different growth stages in diverse organs or tissues. 'Muscat Hamburg' (Vitis 'Muscat of Alexandria' × Vitis 'Trollinger') grapevine was used as test material. High Performance Liquid Chromatography (HPLC) was used to quantify hormone levels, qRT-PCR was used to quantify the expression of genes related to hormone biosynthesis pathway, and determined parameters of growth and photosynthetic, aiming to investigate the influence of root restriction on the formation and metabolism of phytohormones, as well as the degree of correlation between phytohormones and plant growth and photosynthetic intensity under root restriction. By measuring the photosynthetic rate of leaves at the stages of core-hardening, veraison and maturity, it was found that root restriction could reduce most photosynthetic parameters. The results also revealed that RR treatment increased abscisic acid (ABA), salicylic acid (SA), zeatin riboside (ZR), N6-(delta 2-isopentenyl)-adenine nucleoside (iPR) concentrations, while reduced auxin (IAA), 3-indolepropionic acid (IPA), 3-indolebutyric acid (IBA), gibberellin A3 (GA3), zeatin (ZT), N6-(delta 2-Isopentenyl)-adenine (iP), kinetin (KT), jasmonic acid (JA) and methyl jasmonate (MeJA) concentrations in most organs and at most developmental stages. RT-qPCR was carried out to further explore the effect of root restriction on genes expression of ABA, SA and IAA biosynthesis pathways at molecular level. Meanwhile, through correlation analysis, we found that different phytohormones contributed differently to physiological indicators, there existed strong correlation of ABA, KT, MeJA, iPR, SA, JA with leaf photosynthesis, GA3, IBA, ZR, IAA, ZT with fruit quality. In addition, we also found that the shoot growth related parameters were closely correlated with JA, IPA and iP. To sum up, our results suggested that RR treatment could significantly increase soluble solid content, regulate the growth and photosynthesis of grapevine, by affecting the biosynthesis of phytohormones. It could further prove that root restriction was a feasible technique to ameliorate the phenomenon of low quality in grape berry in southern China.
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Affiliation(s)
- Jiajia Li
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Dongmei Li
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Boyang Liu
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Ruiqi Wang
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Yixuan Yan
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Guanhan Li
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Lei Wang
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Chao Ma
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Wenping Xu
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Liping Zhao
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiangyi Li
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
| | - Shiping Wang
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
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9
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Polko JK, Potter KC, Burr CA, Schaller GE, Kieber JJ. Meta-analysis of transcriptomic studies of cytokinin-treated rice roots defines a core set of cytokinin response genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:1387-1402. [PMID: 34165836 DOI: 10.1111/tpj.15386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/06/2021] [Accepted: 06/19/2021] [Indexed: 05/25/2023]
Abstract
Cytokinins regulate diverse aspects of plant growth and development, primarily through modulation of gene expression. The cytokinin-responsive transcriptome has been thoroughly described in dicots, especially Arabidopsis, but much less so in monocots. Here, we present a meta-analysis of five different transcriptomic analyses of rice (Oryza sativa) roots treated with cytokinin, including three previously unpublished experiments. We developed a treatment method in which hormone is added to the media of rice seedlings grown in sterile hydroponic culture under a continuous airflow, which resulted in minimal perturbation of the seedlings, thus greatly reducing changes in gene expression in the absence of exogenous hormone. We defined a core set of 205 upregulated and 86 downregulated genes that were differentially expressed in at least three of the transcriptomic datasets. This core set includes genes encoding the type-A response regulators (RRs) and cytokinin oxidases/dehydrogenases, which have been shown to be primary cytokinin response genes. GO analysis revealed that the upregulated genes were enriched for terms related to cytokinin/hormone signaling and metabolism, while the downregulated genes were significantly enriched for genes encoding transporters. Variations of type-B RR binding motifs were significantly enriched in the promoters of the upregulated genes, as were binding sites for other potential partner transcription factors. The promoters of the downregulated genes were generally enriched for distinct cis-acting motifs and did not include the type-B RR binding motif. This analysis provides insight into the molecular mechanisms underlying cytokinin action in a monocot and provides a useful foundation for future studies of this hormone in rice and other cereals.
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Affiliation(s)
- Joanna K Polko
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Kevin C Potter
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Christian A Burr
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - G Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - Joseph J Kieber
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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10
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Hormonal Regulation and Crosstalk of Auxin/Cytokinin Signaling Pathways in Potatoes In Vitro and in Relation to Vegetation or Tuberization Stages. Int J Mol Sci 2021; 22:ijms22158207. [PMID: 34360972 PMCID: PMC8347663 DOI: 10.3390/ijms22158207] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/11/2022] Open
Abstract
Auxins and cytokinins create versatile regulatory network controlling virtually all aspects of plant growth and development. These hormonal systems act in close contact, synergistically or antagonistically, determining plant phenotype, resistance and productivity. However, the current knowledge about molecular interactions of these systems is still scarce. Our study with potato plants aimed at deciphering potential interactions between auxin and cytokinin signaling pathways at the level of respective gene expression. Potato plants grown on sterile medium with 1.5% (vegetation) or 5% (tuberization) sucrose were treated for 1 h with auxin or cytokinin. Effects of these two hormones on expression profiles of genes belonging to main signaling pathways of auxin and cytokinin were quantified by RT-qPCR. As a result, several signaling genes were found to respond to auxin and/or cytokinin by up- or down-regulation. The observed effects were largely organ-specific and depended on sucrose content. Auxin strongly reduced cytokinin perception apparatus while reciprocal cytokinin effect was ambiguous and sucrose-dependent. In many cases, functional clustering of genes of the same family was observed. Promoters in some clusters are enriched with canonic hormone-response cis-elements supporting their direct sensitivity to hormones. Collectively, our data shed new light on the crosstalk between auxin- and cytokinin signaling pathways.
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11
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Fu X, Su H, Liu S, Du X, Xu C, Luo K. Cytokinin signaling localized in phloem noncell-autonomously regulates cambial activity during secondary growth of Populus stems. THE NEW PHYTOLOGIST 2021; 230:1476-1488. [PMID: 33540480 DOI: 10.1111/nph.17255] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
The regulation of cytokinin on secondary vascular development has been uncovered by modulating cytokinin content. However, it remains unclear how cytokinin enriched in developing secondary phloem regulates cambium activity in poplar. Here, we visualized the gradient distribution of cytokinin with a peak in the secondary phloem of poplar stem via immunohistochemical imaging, and determined the role of phloem-located cytokinin signaling during wood formation. We generated transgenic poplar harboring cytokinin oxidase/dehydrogenase (CKX)2, a gene encoding a cytokinin degrading enzyme, driven by the phloem-specific CLE41b promoter, indicating that the disruption of the cytokinin gradient pattern restricts the cambial activity. The RNA interference-based knockdown of the histidine kinase (HK) genes encoding cytokinin receptors specifically in secondary phloem significantly compromised the division activity of cambial cells, whereas the phloem-specific expression of a type-B response regulator (RR) transcription factor stimulated cambial proliferation, providing evidence for the noncell-autonomous regulation of local cytokinin signaling on the cambial activity. Moreover, the cambium-specific knockdown of HKs also led to restricted cambial activity, and the defects were aggravated by the reduced cytokinin accumulation. Our results showed that local cytokinin signaling in secondary phloem regulates cambial activity noncell-autonomously, and coordinately with its local signaling in cambium.
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Affiliation(s)
- Xiaokang Fu
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Huili Su
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Shuai Liu
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xuelian Du
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Changzheng Xu
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Keming Luo
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China
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12
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Hashem AM, Moore S, Chen S, Hu C, Zhao Q, Elesawi IE, Feng Y, Topping JF, Liu J, Lindsey K, Chen C. Putrescine Depletion Affects Arabidopsis Root Meristem Size by Modulating Auxin and Cytokinin Signaling and ROS Accumulation. Int J Mol Sci 2021; 22:4094. [PMID: 33920993 PMCID: PMC8071467 DOI: 10.3390/ijms22084094] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 02/07/2023] Open
Abstract
Polyamines (PAs) dramatically affect root architecture and development, mainly by unknown mechanisms; however, accumulating evidence points to hormone signaling and reactive oxygen species (ROS) as candidate mechanisms. To test this hypothesis, PA levels were modified by progressively reducing ADC1/2 activity and Put levels, and then changes in root meristematic zone (MZ) size, ROS, and auxin and cytokinin (CK) signaling were investigated. Decreasing putrescine resulted in an interesting inverted-U-trend in primary root growth and a similar trend in MZ size, and differential changes in putrescine (Put), spermidine (Spd), and combined spermine (Spm) plus thermospermine (Tspm) levels. At low Put concentrations, ROS accumulation increased coincidently with decreasing MZ size, and treatment with ROS scavenger KI partially rescued this phenotype. Analysis of double AtrbohD/F loss-of-function mutants indicated that NADPH oxidases were not involved in H2O2 accumulation and that elevated ROS levels were due to changes in PA back-conversion, terminal catabolism, PA ROS scavenging, or another pathway. Decreasing Put resulted in a non-linear trend in auxin signaling, whereas CK signaling decreased, re-balancing auxin and CK signaling. Different levels of Put modulated the expression of PIN1 and PIN2 auxin transporters, indicating changes to auxin distribution. These data strongly suggest that PAs modulate MZ size through both hormone signaling and ROS accumulation in Arabidopsis.
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Affiliation(s)
- Ahmed M. Hashem
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang 550025, China
- Biotechnology Department, Faculty of Agriculture, Al-Azhar University, Cairo 11651, Egypt
| | - Simon Moore
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; (J.F.T.); (J.L.); (K.L.)
| | - Shangjian Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
| | - Chenchen Hu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
| | - Qing Zhao
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
| | - Ibrahim Eid Elesawi
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang 550025, China
- Agricultural Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt
| | - Yanni Feng
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
| | - Jennifer F. Topping
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; (J.F.T.); (J.L.); (K.L.)
| | - Junli Liu
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; (J.F.T.); (J.L.); (K.L.)
| | - Keith Lindsey
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; (J.F.T.); (J.L.); (K.L.)
| | - Chunli Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (A.M.H.); (S.M.); (S.C.); (C.H.); (Q.Z.); (I.E.E.); (Y.F.)
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang 550025, China
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13
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Vaughan-Hirsch J, Tallerday EJ, Burr CA, Hodgens C, Boeshore SL, Beaver K, Melling A, Sari K, Kerr ID, Šimura J, Ljung K, Xu D, Liang W, Bhosale R, Schaller GE, Bishopp A, Kieber JJ. Function of the pseudo phosphotransfer proteins has diverged between rice and Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:159-173. [PMID: 33421204 DOI: 10.1111/tpj.15156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
The phytohormone cytokinin plays a significant role in nearly all aspects of plant growth and development. Cytokinin signaling has primarily been studied in the dicot model Arabidopsis, with relatively little work done in monocots, which include rice (Oryza sativa) and other cereals of agronomic importance. The cytokinin signaling pathway is a phosphorelay comprised of the histidine kinase receptors, the authentic histidine phosphotransfer proteins (AHPs) and type-B response regulators (RRs). Two negative regulators of cytokinin signaling have been identified: the type-A RRs, which are cytokinin primary response genes, and the pseudo histidine phosphotransfer proteins (PHPs), which lack the His residue required for phosphorelay. Here, we describe the role of the rice PHP genes. Phylogenic analysis indicates that the PHPs are generally first found in the genomes of gymnosperms and that they arose independently in monocots and dicots. Consistent with this, the three rice PHPs fail to complement an Arabidopsis php mutant (aphp1/ahp6). Disruption of the three rice PHPs results in a molecular phenotype consistent with these elements acting as negative regulators of cytokinin signaling, including the induction of a number of type-A RR and cytokinin oxidase genes. The triple php mutant affects multiple aspects of rice growth and development, including shoot morphology, panicle architecture, and seed fill. In contrast to Arabidopsis, disruption of the rice PHPs does not affect root vascular patterning, suggesting that while many aspects of key signaling networks are conserved between monocots and dicots, the roles of at least some cytokinin signaling elements are distinct.
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Affiliation(s)
| | - Emily J Tallerday
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Christian A Burr
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Charlie Hodgens
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Samantha L Boeshore
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Kevin Beaver
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Allison Melling
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Kartika Sari
- School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK
- FKIP, Universitas Muhammadiyah Metro, Lampung, 34111, Indonesia
| | - Ian D Kerr
- University of Nottingham, Loughborough, NG7 2UH, UK
| | - Jan Šimura
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), Umeå, 901 83, Sweden
| | - Karin Ljung
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), Umeå, 901 83, Sweden
| | - Dawei Xu
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Wanqi Liang
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Rahul Bhosale
- School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK
- Future Food Beacon of Excellence and School of Biosciences, University of Nottingham, LE12 5RD, UK
| | - G Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - Anthony Bishopp
- School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK
| | - Joseph J Kieber
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
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14
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He G, Yang P, Cao Y, Tang Y, Wang L, Song M, Wang J, Xu L, Ming J. Cytokinin Type-B Response Regulators Promote Bulbil Initiation in Lilium lancifolium. Int J Mol Sci 2021; 22:ijms22073320. [PMID: 33805045 PMCID: PMC8037933 DOI: 10.3390/ijms22073320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 11/24/2022] Open
Abstract
The bulbil is an important vegetative reproductive organ in triploid Lilium lancifolium whose development is promoted by cytokinins. Type-B response regulators (RRs) are critical regulators that mediate primary cytokinin responses and promote cytokinin-induced gene expression. However, the function of cytokinin type-B Arabidopsis RRs (ARRs) in regulating bulbil formation is unclear. In this study, we identified five type-B LlRRs, LlRR1, LlRR2, LlRR10, LlRR11 and LlRR12, in L. lancifolium for the first time. The five LlRRs encode proteins of 715, 675, 573, 582 and 647 amino acids. All of the regulators belong to the B-I subfamily, whose members typically contain a conserved CheY-homologous receiver (REC) domain and an Myb DNA-binding (MYB) domain at the N-terminus. As transcription factors, all five type-B LlRRs localize at the nucleus and are widely expressed in plant tissues, especially during axillary meristem (AM) formation. Functional analysis showed that type-B LlRRs are involved in bulbil formation in a functionally redundant manner and can activate LlRR9 expression. In summary, our study elucidates the process by which cytokinins regulate bulbil initiation in L. lancifolium through type-B LlRRs and lays a foundation for research on the molecular mechanism of bulbil formation in the lily.
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Affiliation(s)
- Guoren He
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
| | - Panpan Yang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
- Correspondence: (P.Y.); (J.M.)
| | - Yuwei Cao
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
| | - Yuchao Tang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
| | - Ling Wang
- School of Foresty and Landscape Architecture, Anhui Agricultural University, Hefei 230036, China;
| | - Meng Song
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
| | - Jing Wang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
| | - Leifeng Xu
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
| | - Jun Ming
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (G.H.); (Y.C.); (Y.T.); (M.S.); (J.W.); (L.X.)
- Correspondence: (P.Y.); (J.M.)
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15
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Jiang L, Yoshida T, Stiegert S, Jing Y, Alseekh S, Lenhard M, Pérez-Alfocea F, Fernie AR. Multi-omics approach reveals the contribution of KLU to leaf longevity and drought tolerance. PLANT PHYSIOLOGY 2021; 185:352-368. [PMID: 33721894 PMCID: PMC8133585 DOI: 10.1093/plphys/kiaa034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/05/2020] [Indexed: 05/05/2023]
Abstract
KLU, encoded by a cytochrome P450 CYP78A family gene, generates an important-albeit unknown-mobile signal that is distinct from the classical phytohormones. Multiple lines of evidence suggest that KLU/KLU-dependent signaling functions in several vital developmental programs, including leaf initiation, leaf/floral organ growth, and megasporocyte cell fate. However, the interactions between KLU/KLU-dependent signaling and the other classical phytohormones, as well as how KLU influences plant physiological responses, remain poorly understood. Here, we applied in-depth, multi-omics analysis to monitor transcriptome and metabolome dynamics in klu-mutant and KLU-overexpressing Arabidopsis plants. By integrating transcriptome sequencing data and primary metabolite profiling alongside phytohormone measurements, our results showed that cytokinin signaling, with its well-established function in delaying leaf senescence, was activated in KLU-overexpressing plants. Consistently, KLU-overexpressing plants exhibited significantly delayed leaf senescence and increased leaf longevity, whereas the klu-mutant plants showed early leaf senescence. In addition, proline biosynthesis and catabolism were enhanced following KLU overexpression owing to increased expression of genes associated with proline metabolism. Furthermore, KLU-overexpressing plants showed enhanced drought-stress tolerance and reduced water loss. Collectively, our work illustrates a role for KLU in positively regulating leaf longevity and drought tolerance by synergistically activating cytokinin signaling and promoting proline metabolism. These data promote KLU as a potential ideal genetic target to improve plant fitness.
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Affiliation(s)
- Liang Jiang
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Takuya Yoshida
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Sofia Stiegert
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Genetics, University of Potsdam, 14469 Potsdam, Germany
| | - Yue Jing
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Saleh Alseekh
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Michael Lenhard
- Department of Genetics, University of Potsdam, 14469 Potsdam, Germany
| | - Francisco Pérez-Alfocea
- Department of Plant Nutrition, CEBAS-CSIC, Campus Universitario de Espinardo, 30100 Murcia, Spain
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Genetics, University of Potsdam, 14469 Potsdam, Germany
- Author for communication:
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16
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Hodgens C, Chang N, Schaller GE, Kieber JJ. Mutagenomics: A Rapid, High-Throughput Method to Identify Causative Mutations from a Genetic Screen. PLANT PHYSIOLOGY 2020; 184:1658-1673. [PMID: 32887734 PMCID: PMC7723078 DOI: 10.1104/pp.20.00609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/02/2020] [Indexed: 05/30/2023]
Abstract
Genetic screens are powerful tools to dissect complex biological processes, but a rate-limiting step is often the cloning of targeted genes. Here, we present a strategy, "mutagenomics," to identify causal mutations from a screen in a high throughput fashion in the absence of backcrossing. Mutagenomics is initiated by sequencing the genomes of the mutants identified, which are then subjected to a three-stage pipeline. The first stage identifies sequence changes in genes previously linked to the targeted pathway. The second stage uses heuristics derived from a simulation strategy to identify genes that are represented by multiple independent alleles more often than expected by chance. The third stage identifies candidate genes for the remaining lines by sequencing multiple lines of common descent. Our simulations indicate that sequencing as few as three to four sibling lines generally results in fewer than five candidate genes. We applied mutagenomics to a screen for Arabidopsis (Arabidopsis thaliana) mutants involved in the response to the phytohormone cytokinin. Mutagenomics identified likely causative genes for many of the mutant lines analyzed from this screen, including 13 alleles of the gene encoding the ARABIDOPSIS HIS KINASE4 cytokinin receptor. The screen also identified 1-AMINOCYCLOPROPANE-1-CARBOXYLATE (ACC) SYNTHASE7, an ACC synthase homolog involved in ethylene biosynthesis, and ELONGATED HYPOCOTYL5 (HY5), a master transcriptional regulator of photomorphogenesis. HY5 was found to mediate a subset of the transcriptional response to cytokinin. Mutagenomics has the potential to accelerate the pace and utility of genetic screens in Arabidopsis.
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Affiliation(s)
- Charles Hodgens
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Nicole Chang
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - G Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
| | - Joseph J Kieber
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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17
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Burr CA, Sun J, Yamburenko MV, Willoughby A, Hodgens C, Boeshore SL, Elmore A, Atkinson J, Nimchuk ZL, Bishopp A, Schaller GE, Kieber JJ. The HK5 and HK6 cytokinin receptors mediate diverse developmental pathways in rice. Development 2020; 147:dev191734. [PMID: 33028608 PMCID: PMC7648598 DOI: 10.1242/dev.191734] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 09/23/2020] [Indexed: 12/22/2022]
Abstract
The phytohormone cytokinin regulates diverse aspects of plant growth and development. Our understanding of the metabolism and perception of cytokinin has made great strides in recent years, mostly from studies of the model dicot Arabidopsis Here, we employed a CRISPR/Cas9-based approach to disrupt a subset of cytokinin histidine kinase (HK) receptors in rice (Oryza sativa) in order to explore the role of cytokinin in a monocot species. In hk5 and hk6 single mutants, the root growth, leaf width, inflorescence architecture and/or floral development were affected. The double hk5 hk6 mutant showed more substantial defects, including severely reduced root and shoot growth, a smaller shoot apical meristem, and an enlarged root cap. Flowering was delayed in the hk5 hk6 mutant and the panicle was significantly reduced in size and infertile due to multiple defects in floral development. The hk5 hk6 mutant also exhibited a severely reduced cytokinin response, consistent with the developmental phenotypes arising from a defect in cytokinin signaling. These results indicate that HK5 and HK6 act as cytokinin receptors, with overlapping functions to regulate diverse aspects of rice growth and development.
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Affiliation(s)
- Christian A Burr
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jinjing Sun
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Andrew Willoughby
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Charles Hodgens
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Agustus Elmore
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jonathan Atkinson
- School of Bioscience, University of Nottingham, Nottingham LE12 5RD, UK
| | - Zachary L Nimchuk
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Anthony Bishopp
- School of Bioscience, University of Nottingham, Nottingham LE12 5RD, UK
| | - G Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
| | - Joseph J Kieber
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
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18
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Lin J, Frank M, Reid D. No Home without Hormones: How Plant Hormones Control Legume Nodule Organogenesis. PLANT COMMUNICATIONS 2020; 1:100104. [PMID: 33367261 PMCID: PMC7747975 DOI: 10.1016/j.xplc.2020.100104] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 05/08/2023]
Abstract
The establishment of symbiotic nitrogen fixation requires the coordination of both nodule development and infection events. Despite the evolution of a variety of anatomical structures, nodule organs serve a common purpose in establishing a localized area that facilitates efficient nitrogen fixation. As in all plant developmental processes, the establishment of a new nodule organ is regulated by plant hormones. During nodule initiation, regulation of plant hormone signaling is one of the major targets of symbiotic signaling. We review the role of major developmental hormones in the initiation of the nodule organ and argue that the manipulation of plant hormones is a key requirement for engineering nitrogen fixation in non-legumes as the basis for improved food security and sustainability.
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Affiliation(s)
- Jieshun Lin
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Manuel Frank
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Dugald Reid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Corresponding author
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19
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Research Progress on the Roles of Cytokinin in Plant Response to Stress. Int J Mol Sci 2020; 21:ijms21186574. [PMID: 32911801 PMCID: PMC7555750 DOI: 10.3390/ijms21186574] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 01/05/2023] Open
Abstract
Cytokinins promote plant growth and development under normal plant growth conditions and also play an important role in plant resistance to stress. Understanding the working mechanisms of cytokinins under adverse conditions will help to make full use of cytokinins in agriculture to increase production and efficiency of land use. In this article, we review the progress that has been made in cytokinin research in plant response to stress and propose its future application prospects.
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20
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Zhu C, Xiaoyu L, Junlan G, Yun X, Jie R. Integrating transcriptomic and metabolomic analysis of hormone pathways in Acer rubrum during developmental leaf senescence. BMC PLANT BIOLOGY 2020; 20:410. [PMID: 32883206 PMCID: PMC7650285 DOI: 10.1186/s12870-020-02628-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND To fully elucidate the roles and mechanisms of plant hormones in leaf senescence, we adopted an integrated analysis of both non-senescing and senescing leaves from red maple with transcriptome and metabolome data. RESULTS Transcription and metabolite profiles were generated through a combination of deep sequencing, third-generation sequencing data analysis, and ultrahigh-performance liquid chromatograph Q extractive mass spectrometry (UHPLC-QE-MS), respectively. We investigated the accumulation of compounds and the expression of biosynthesis and signaling genes for eight hormones. The results revealed that ethylene and abscisic acid concentrations increased during the leaf senescence process, while the contents of cytokinin, auxin, jasmonic acid, and salicylic acid continued to decrease. Correlation tests between the hormone content and transcriptional changes were analyzed, and in six pathways, genes closely linked with leaf senescence were identified. CONCLUSIONS These results will enrich our understanding of the mechanisms of plant hormones that regulate leaf senescence in red maple, while establishing a foundation for the genetic modification of Acer in the future.
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Affiliation(s)
- Chen Zhu
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 Nongkenanlu, Hefei, Anhui 230031 P.R. China
| | - Lu Xiaoyu
- College of Forestry and Landscape Architecture, Anhui Agricultural University, 130 Changjiangxilu, Hefei, Anhui 230036 P.R. China
| | - Gao Junlan
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 Nongkenanlu, Hefei, Anhui 230031 P.R. China
| | - Xuan Yun
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 Nongkenanlu, Hefei, Anhui 230031 P.R. China
| | - Ren Jie
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 Nongkenanlu, Hefei, Anhui 230031 P.R. China
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21
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Shi F, Wang M, An Y. Overexpression of a B-type cytokinin response regulator ( OsORR2) reduces plant height in rice. PLANT SIGNALING & BEHAVIOR 2020; 15:1780405. [PMID: 32552330 PMCID: PMC8570751 DOI: 10.1080/15592324.2020.1780405] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 05/19/2023]
Abstract
Cytokinin plays crucial roles in regulating plant growth and development, with the signal transduction mediated by type-A and type-B response regulators (RRs).While much genetic knowledge about RRs on regulating plant height remains unclear. Here, we found that overexpressing an OsORR2 gene (a type-B RR) could reduce plant height in rice compared with the wild type (WT). Using quantitative real time (RT-qPCR) assay, OsORR2was expressed widely in most tissues such as root, culm, sheath, leaf, and panicle. Strong signals were detected in leaf mesophyll cells and anther by in situ hybridization assays (ISH). The subcellular localization of OsORR2 was in cell nucleus. In addition, we found that the transcriptional expression levels of type-A RR genes such as OsRR9, OsRR10, OsRR12, and OsRR13 were significantly up-regulated in the overexpression transgenic plants (OE) plants. Taken together, our data suggested that OsORR2was involved in the development of plant height in rice and provided a foundation for future deep molecular research of the type-B RRs.
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Affiliation(s)
- Fachao Shi
- Guangdong Bioengineering Institute (Guangzhou Sugarcane Industry Research Institute), Guangdong Engineering Research Center for Pesticide & Fertilizer, Guangzhou, China
| | - Min Wang
- Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Yuxing An
- Guangdong Bioengineering Institute (Guangzhou Sugarcane Industry Research Institute), Guangdong Engineering Research Center for Pesticide & Fertilizer, Guangzhou, China
- CONTACT Yuxing an Bioengineering Building No.1905, Shiliugang road 10#, Haizhu District, Gungzhou city, China
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Ali S, Khan N, Xie L. Molecular and Hormonal Regulation of Leaf Morphogenesis in Arabidopsis. Int J Mol Sci 2020; 21:ijms21145132. [PMID: 32698541 PMCID: PMC7404056 DOI: 10.3390/ijms21145132] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 12/28/2022] Open
Abstract
Shoot apical meristems (SAM) are tissues that function as a site of continuous organogenesis, which indicates that a small pool of pluripotent stem cells replenishes into lateral organs. The coordination of intercellular and intracellular networks is essential for maintaining SAM structure and size and also leads to patterning and formation of lateral organs. Leaves initiate from the flanks of SAM and then develop into a flattened structure with variable sizes and forms. This process is mainly regulated by the transcriptional regulators and mechanical properties that modulate leaf development. Leaf initiation along with proper orientation is necessary for photosynthesis and thus vital for plant survival. Leaf development is controlled by different components such as hormones, transcription factors, miRNAs, small peptides, and epigenetic marks. Moreover, the adaxial/abaxial cell fate, lamina growth, and shape of margins are determined by certain regulatory mechanisms. The over-expression and repression of various factors responsible for leaf initiation, development, and shape have been previously studied in several mutants. However, in this review, we collectively discuss how these factors modulate leaf development in the context of leaf initiation, polarity establishment, leaf flattening and shape.
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Affiliation(s)
- Shahid Ali
- College of Life Sciences, Northeast Forestry University, Harbin 150040, China
- Correspondence: (S.A.); (L.X.)
| | - Naeem Khan
- Department of Agronomy, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA;
| | - Linan Xie
- College of Life Sciences, Northeast Forestry University, Harbin 150040, China
- Key Laboratory of Saline-Alkali Vegetative Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
- Correspondence: (S.A.); (L.X.)
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23
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Huo R, Liu Z, Yu X, Li Z. The Interaction Network and Signaling Specificity of Two-Component System in Arabidopsis. Int J Mol Sci 2020; 21:ijms21144898. [PMID: 32664520 PMCID: PMC7402358 DOI: 10.3390/ijms21144898] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 01/25/2023] Open
Abstract
Two-component systems (TCS) in plants have evolved into a more complicated multi-step phosphorelay (MSP) pathway, which employs histidine kinases (HKs), histidine-containing phosphotransfer proteins (HPts), and response regulators (RRs) to regulate various aspects of plant growth and development. How plants perceive the external signals, then integrate and transduce the secondary signals specifically to the desired destination, is a fundamental characteristic of the MSP signaling network. The TCS elements involved in the MSP pathway and molecular mechanisms of signal transduction have been best understood in the model plant Arabidopsis thaliana. In this review, we focus on updated knowledge on TCS signal transduction in Arabidopsis. We first present a brief description of the TCS elements; then, the protein–protein interaction network is established. Finally, we discuss the possible molecular mechanisms involved in the specificity of the MSP signaling at the mRNA and protein levels.
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Affiliation(s)
- Ruxue Huo
- Institute of Integrative Plant Biology, Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China;
- College of Agriculture and Forestry Sciences, Linyi University, Linyi 276000, China
| | - Zhenning Liu
- College of Agriculture and Forestry Sciences, Linyi University, Linyi 276000, China
- Correspondence: (Z.L.); (Z.L.)
| | - Xiaolin Yu
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China;
| | - Zongyun Li
- Institute of Integrative Plant Biology, Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China;
- Correspondence: (Z.L.); (Z.L.)
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24
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Novel markers for high-throughput protoplast-based analyses of phytohormone signaling. PLoS One 2020; 15:e0234154. [PMID: 32497144 PMCID: PMC7272087 DOI: 10.1371/journal.pone.0234154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/19/2020] [Indexed: 02/03/2023] Open
Abstract
Phytohormones mediate most diverse processes in plants, ranging from organ development to immune responses. Receptor protein complexes perceive changes in intracellular phytohormone levels and trigger a signaling cascade to effectuate downstream responses. The in planta analysis of elements involved in phytohormone signaling can be achieved through transient expression in mesophyll protoplasts, which are a fast and versatile alternative to generating plant lines that stably express a transgene. While promoter-reporter constructs have been used successfully to identify internal or external factors that change phytohormone signaling, the range of available marker constructs does not meet the potential of the protoplast technique for large scale approaches. The aim of our study was to provide novel markers for phytohormone signaling in the Arabidopsis mesophyll protoplast system. We validated 18 promoter::luciferase constructs towards their phytohormone responsiveness and specificity and suggest an experimental setup for high-throughput analyses. We recommend novel markers for the analysis of auxin, abscisic acid, cytokinin, salicylic acid and jasmonic acid responses that will facilitate future screens for biological elements and environmental stimuli affecting phytohormone signaling.
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25
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Ahmad B, Azeem F, Ali MA, Nawaz MA, Nadeem H, Abbas A, Batool R, Atif RM, Ijaz U, Nieves-Cordones M, Chung G. Genome-wide identification and expression analysis of two component system genes in Cicer arietinum. Genomics 2020; 112:1371-1383. [DOI: 10.1016/j.ygeno.2019.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/19/2019] [Accepted: 08/11/2019] [Indexed: 10/26/2022]
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26
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Zubo YO, Schaller GE. Role of the Cytokinin-Activated Type-B Response Regulators in Hormone Crosstalk. PLANTS 2020; 9:plants9020166. [PMID: 32019090 PMCID: PMC7076656 DOI: 10.3390/plants9020166] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 01/24/2020] [Accepted: 01/24/2020] [Indexed: 02/06/2023]
Abstract
Cytokinin is an important phytohormone that employs a multistep phosphorelay to transduce the signal from receptors to the nucleus, culminating in activation of type-B response regulators which function as transcription factors. Recent chromatin immunoprecipitation-sequencing (ChIP-seq) studies have identified targets of type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs) and integrated these into the cytokinin-activated transcriptional network. Primary targets of the type-B ARRs are enriched for genes involved in hormonal regulation, emphasizing the extensive crosstalk that can occur between cytokinin, auxin, abscisic acid, brassinosteroids, gibberellic acid, ethylene, jasmonic acid, and salicylic acid. Examination of hormone-related targets reveals multiple regulatory points including biosynthesis, degradation/inactivation, transport, and signal transduction. Here, we consider this early response to cytokinin in terms of the hormones involved, points of regulatory crosstalk, and physiological significance.
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27
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Wang WC, Lin TC, Kieber J, Tsai YC. Response Regulators 9 and 10 Negatively Regulate Salinity Tolerance in Rice. PLANT & CELL PHYSIOLOGY 2019; 60:2549-2563. [PMID: 31359043 DOI: 10.1093/pcp/pcz149] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/19/2019] [Indexed: 05/23/2023]
Abstract
Cytokinins are involved in the regulation of many plant growth and development processes, and function in response to abiotic stress. Cytokinin signaling is similar to the prokaryotic two-component signaling systems and includes the transcriptional upregulation of type-A response regulators (RRs), which in turn act to inhibit cytokinin signal response via negative feedback. Cytokinin signaling consists of several gene families and only a handful full of genes is studied. In this study, we demonstrated the function of two highly identical type-A RR genes from rice, OsRR9 and OsRR10, which are induced by cytokinin and only OsRR10 repressed by salinity stress in rice. Loss-of-function mutations give rise to mutant genes, osrr9/osrr10, which have higher salinity tolerance than wild type rice seedlings. The transcriptomic analysis uncovered several ion transporter genes, which were upregulated in response to salt stress in the osrr9/osrr10 mutants relative to the wild type seedlings. These include high-affinity potassium transporters, such as OsHKT1;1, OsHKT1;3 and OsHKT2;1, which play an important role in sodium and potassium homeostasis. In addition, disruption of the genes OsRR9 and OsRR10 also affects the expression of multiple genes related to photosynthesis, transcription and phytohormone signaling. Taken together, these results suggest that the genes OsRR9 and OsRR10 function as negative regulators in response to salinity in rice.
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Affiliation(s)
- Wei-Chen Wang
- Department of Agronomy, National Taiwan University, Roosevelt Road, Taipei, Taiwan
| | - Te-Che Lin
- Department of Agronomy, National Taiwan University, Roosevelt Road, Taipei, Taiwan
| | - Joseph Kieber
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
| | - Yu-Chang Tsai
- Department of Agronomy, National Taiwan University, Roosevelt Road, Taipei, Taiwan
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28
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Zdarska M, Cuyacot AR, Tarr PT, Yamoune A, Szmitkowska A, Hrdinová V, Gelová Z, Meyerowitz EM, Hejátko J. ETR1 Integrates Response to Ethylene and Cytokinins into a Single Multistep Phosphorelay Pathway to Control Root Growth. MOLECULAR PLANT 2019; 12:1338-1352. [PMID: 31176773 PMCID: PMC8040967 DOI: 10.1016/j.molp.2019.05.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 04/17/2019] [Accepted: 05/28/2019] [Indexed: 05/18/2023]
Abstract
Cytokinins and ethylene control plant development via sensors from the histidine kinase (HK) family. However, downstream signaling pathways for the key phytohormones are distinct. Here we report that not only cytokinin but also ethylene is able to control root apical meristem (RAM) size through activation of the multistep phosphorelay (MSP) pathway. We found that both cytokinin and ethylene-dependent RAM shortening requires ethylene binding to ETR1 and the HK activity of ETR1. The receiver domain of ETR1 interacts with MSP signaling intermediates acting downstream of cytokinin receptors, further substantiating the role of ETR1 in MSP signaling. We revealed that both cytokinin and ethylene induce the MSP in similar and distinct cell types with ETR1-mediated ethylene signaling controlling MSP output specifically in the root transition zone. We identified members of the MSP pathway specific and common to both hormones and showed that ETR1-regulated ARR3 controls RAM size. ETR1-mediated MSP spatially differs from canonical CTR1/EIN2/EIN3 ethylene signaling and is independent of EIN2, indicating that both pathways can be spatially and functionally separated. Furthermore, we demonstrated that canonical ethylene signaling controls MSP responsiveness to cytokinin specifically in the root transition zone, presumably via regulation of ARR10, one of the positive regulators of MSP signaling in Arabidopsis.
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Affiliation(s)
- Marketa Zdarska
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic; Division of Biology and Biological Engineering 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
| | - Abigail Rubiato Cuyacot
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Paul T Tarr
- Howard Hughes Medical Institute, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; Division of Biology and Biological Engineering 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Amel Yamoune
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Agnieszka Szmitkowska
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Vendula Hrdinová
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Zuzana Gelová
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic
| | - Elliot M Meyerowitz
- Howard Hughes Medical Institute, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; Division of Biology and Biological Engineering 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Jan Hejátko
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, CETEC-MU, Kamenice 5/A2, 625 00 Brno, Czech Republic.
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29
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Chen P, Jiao X, Zhang Y, Wu L, Tang DJ, Li P, Chen X, Chao D, Tang JL, Ming Z. The crystal structure of the phytopathogenic bacterial sensor PcrK reveals different cytokinin recognition mechanism from the plant sensor AHK4. J Struct Biol 2019; 208:69-76. [PMID: 31419523 DOI: 10.1016/j.jsb.2019.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/01/2019] [Accepted: 08/05/2019] [Indexed: 10/26/2022]
Abstract
Plant cytokinins (CKs) are essential for many central cellular processes and play important roles in the interaction between bacteria and plants. Perception of CK is executed by the CHASE domain in the histidine kinase sensors of a class of two-component regulatory systems. Despite advances in understanding the structural basis for CK perception by the sensor AHK4 in Arabidopsis, the molecular mechanism of CK binding by other sensors is unclear. Here, we report the crystal structure of the CHASE domain in the histidine kinase PcrK of the bacterial plant pathogen Xanthomonas campestris pathovar campestris, which senses plant CK, determined at 2.55 Å resolution. The structure reveals that the PcrK has an AHK4-like overall topology and assembles into a homodimer. Strikingly, detailed structural analysis unveils two unique features of the PcrK ligand binding pocket: the size of the pocket is restricted for CK binding, and the PcrK applies a positively charged arginine but not a negatively charged aspartate to recognize the ligand. We propose a model to explain how the PcrK accommodates CK-sized compounds through conformational changes, providing a potential mechanistic framework for understanding ligand recognition by the PcrK.
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Affiliation(s)
- Peng Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Xi Jiao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Yukun Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Lijie Wu
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Dong-Jie Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Peifang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Xiaoxuan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Dong Chao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China.
| | - Zhenhua Ming
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China.
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Cammarata J, Roeder AH, Scanlon MJ. Cytokinin and CLE signaling are highly intertwined developmental regulators across tissues and species. CURRENT OPINION IN PLANT BIOLOGY 2019; 51:96-104. [PMID: 31280129 DOI: 10.1016/j.pbi.2019.05.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 05/18/2023]
Abstract
The control of cell identity and differentiation is critical for proper development. In plants, cell identity is largely determined by a cell's spatial context, which is communicated in the form of varying abundances of hormones. Two classes of hormones, the classical phytohormone cytokinin and the small CLE peptide hormones, are potent regulators of cell division and cell differentiation. While a relationship between these two classes of hormones is well-established at developing shoot tips, recent evidence suggests that CLE and cytokinin signaling converge on the same developmental processes across many different contexts and in widely divergent species. Here, we review evidence predominately from Arabidopsis thaliana and the moss Physcomitrella patens that supports a general model where CLE and cytokinin signaling are highly intertwined developmental regulators with antagonistic functions in shoots and synergistic functions in roots.
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Affiliation(s)
- Joseph Cammarata
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, United States; Weill Institute for Cell and Molecular Biology, Cornell University, United States
| | - Adrienne Hk Roeder
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, United States; Weill Institute for Cell and Molecular Biology, Cornell University, United States
| | - Michael J Scanlon
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, United States
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31
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Lee ZH, Hirakawa T, Yamaguchi N, Ito T. The Roles of Plant Hormones and Their Interactions with Regulatory Genes in Determining Meristem Activity. Int J Mol Sci 2019; 20:ijms20164065. [PMID: 31434317 PMCID: PMC6720427 DOI: 10.3390/ijms20164065] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/08/2019] [Accepted: 08/16/2019] [Indexed: 12/11/2022] Open
Abstract
Plants, unlike animals, have developed a unique system in which they continue to form organs throughout their entire life cycle, even after embryonic development. This is possible because plants possess a small group of pluripotent stem cells in their meristems. The shoot apical meristem (SAM) plays a key role in forming all of the aerial structures of plants, including floral meristems (FMs). The FMs subsequently give rise to the floral organs containing reproductive structures. Studies in the past few decades have revealed the importance of transcription factors and secreted peptides in meristem activity using the model plant Arabidopsis thaliana. Recent advances in genomic, transcriptomic, imaging, and modeling technologies have allowed us to explore the interplay between transcription factors, secreted peptides, and plant hormones. Two different classes of plant hormones, cytokinins and auxins, and their interaction are particularly important for controlling SAM and FM development. This review focuses on the current issues surrounding the crosstalk between the hormonal and genetic regulatory network during meristem self-renewal and organogenesis.
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Affiliation(s)
- Ze Hong Lee
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Takeshi Hirakawa
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Nobutoshi Yamaguchi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi-shi, Saitama 332-0012, Japan
| | - Toshiro Ito
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan.
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Strigolactone promotes cytokinin degradation through transcriptional activation of CYTOKININ OXIDASE/DEHYDROGENASE 9 in rice. Proc Natl Acad Sci U S A 2019; 116:14319-14324. [PMID: 31235564 PMCID: PMC6628823 DOI: 10.1073/pnas.1810980116] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Strigolactone plays a vital role in plant growth and development, but its response genes remain to be identified. In this study, we found that cytokinin content is markedly increased in the strigolactone signaling mutant d53, and that OsCKX9, which encodes a cytokinin oxidase to catalyze the degradation of cytokinin, functions as a primary strigolactone-responsive gene to regulate rice tillering, plant height, and panicle size, likely via a secondary response gene, OsRR5, which encodes a cytokinin-inducible rice type-A response regulator, demonstrating that strigolactone regulates rice shoot architecture through enhanced cytokinin catabolism by modulating OsCKX9 expression. Strigolactones (SLs), a group of terpenoid lactones derived from carotenoids, are plant hormones that control numerous aspects of plant development. Although the framework of SL signaling that the repressor DWARF 53 (D53) could be SL-dependently degraded via the SL receptor D14 and F-box protein D3 has been established, the downstream response genes to SLs remain to be elucidated. Here we show that the cytokinin (CK) content is dramatically increased in shoot bases of the rice SL signaling mutant d53. By examining transcript levels of all the CK metabolism-related genes after treatment with SL analog GR24, we identified CYTOKININ OXIDASE/DEHYDROGENASE 9 (OsCKX9) as a primary response gene significantly up-regulated within 1 h of treatment in the wild type but not in d53. We also found that OsCKX9 functions as a cytosolic and nuclear dual-localized CK catabolic enzyme, and that the overexpression of OsCKX9 suppresses the browning of d53 calli. Both the CRISPR/Cas9-generated OsCKX9 mutants and OsCKX9-overexpressing transgenic plants showed significant increases in tiller number and decreases in plant height and panicle size, suggesting that the homeostasis of OsCKX9 plays a critical role in regulating rice shoot architecture. Moreover, we identified the CK-inducible rice type-A response regulator OsRR5 as the secondary SL-responsive gene, whose expression is significantly repressed after 4 h of GR24 treatment in the wild type but not in osckx9. These findings reveal a comprehensive plant hormone cross-talk in which SL can induce the expression of OsCKX9 to down-regulate CK content, which in turn triggers the response of downstream genes.
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Singh D, Raina TK, Kumar A, Singh J, Prasad R. Plant microbiome: A reservoir of novel genes and metabolites. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.plgene.2019.100177] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tan S, Debellé F, Gamas P, Frugier F, Brault M. Diversification of cytokinin phosphotransfer signaling genes in Medicago truncatula and other legume genomes. BMC Genomics 2019; 20:373. [PMID: 31088345 PMCID: PMC6518804 DOI: 10.1186/s12864-019-5724-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/22/2019] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Legumes can establish on nitrogen-deprived soils a symbiotic interaction with Rhizobia bacteria, leading to the formation of nitrogen-fixing root nodules. Cytokinin phytohormones are critical for triggering root cortical cell divisions at the onset of nodule initiation. Cytokinin signaling is based on a Two-Component System (TCS) phosphorelay cascade, involving successively Cytokinin-binding Histidine Kinase receptors, phosphorelay proteins shuttling between the cytoplasm and the nucleus, and Type-B Response Regulator (RRB) transcription factors activating the expression of cytokinin primary response genes. Among those, Type-A Response Regulators (RRA) exert a negative feedback on the TCS signaling. To determine whether the legume plant nodulation capacity is linked to specific features of TCS proteins, a genome-wide identification was performed in six legume genomes (Cajanus cajan, pigeonpea; Cicer arietinum, chickpea; Glycine max, soybean; Phaseolus vulgaris, common bean; Lotus japonicus; Medicago truncatula). The diversity of legume TCS proteins was compared to the one found in two non-nodulating species, Arabidopsis thaliana and Vitis vinifera, which are references for functional analyses of TCS components and phylogenetic analyses, respectively. RESULTS A striking expansion of non-canonical RRBs was identified, notably leading to the emergence of proteins where the conserved phosphor-accepting aspartate residue is replaced by a glutamate or an asparagine. M. truncatula genome-wide expression datasets additionally revealed that only a limited subset of cytokinin-related TCS genes is highly expressed in different organs, namely MtCHK1/MtCRE1, MtHPT1, and MtRRB3, suggesting that this "core" module potentially acts in most plant organs including nodules. CONCLUSIONS Further functional analyses are required to determine the relevance of these numerous non-canonical TCS RRBs in symbiotic nodulation, as well as of canonical MtHPT1 and MtRRB3 core signaling elements.
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Affiliation(s)
- Sovanna Tan
- IPS2 (Institute of Plant Sciences Paris-Saclay), CNRS, Université Paris-Sud, Université Paris-Diderot, INRA, Université d’Evry, Université Paris-Saclay, Rue de Noetzlin, 91190 Gif-sur-Yvette, France
| | - Frédéric Debellé
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - Pascal Gamas
- LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - Florian Frugier
- IPS2 (Institute of Plant Sciences Paris-Saclay), CNRS, Université Paris-Sud, Université Paris-Diderot, INRA, Université d’Evry, Université Paris-Saclay, Rue de Noetzlin, 91190 Gif-sur-Yvette, France
| | - Mathias Brault
- IPS2 (Institute of Plant Sciences Paris-Saclay), CNRS, Université Paris-Sud, Université Paris-Diderot, INRA, Université d’Evry, Université Paris-Saclay, Rue de Noetzlin, 91190 Gif-sur-Yvette, France
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35
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Li C, Zhang W, Yuan M, Jiang L, Sun B, Zhang D, Shao Y, Liu A, Liu X, Ma J. Transcriptome analysis of osmotic-responsive genes in ABA-dependent and -independent pathways in wheat ( Triticum aestivum L.) roots. PeerJ 2019; 7:e6519. [PMID: 30863676 PMCID: PMC6407504 DOI: 10.7717/peerj.6519] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 01/21/2019] [Indexed: 11/20/2022] Open
Abstract
Bread wheat is one of the most important crops in the world. However, osmotic stress significantly inhibits wheat growth and development, and reduces crop yield and quality. Plants respond to osmotic stress mainly through abscisic acid (ABA)-dependent and -independent pathways. In this study, root transcriptome profiles of wheat seedlings exposed to osmotic stress and exogenous ABA were analysed to identify osmotic-responsive genes belonging to the ABA-dependent or -independent pathways. We found that osmotic stress promoted proline biosynthesis in the ABA-dependent pathway, and trehalose biosynthesis is likely promoted among soluble sugars to maintain protein bioactivity under osmotic stress. In wheat roots subjected to osmotic stress, calcium ions, and glutathione exert their functions mainly through calcium-binding protein (CaM/CML) and glutathione-S-transferase, respectively, depending on both pathways. In addition, a complex relationship among phytohormones signal transduction was observed in response to osmotic stress. The findings of this study deepen our understanding of the molecular mechanisms of osmotic-stress resistance, and provide several candidate osmotic-responsive genes for further study.
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Affiliation(s)
- Chunxi Li
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Wenli Zhang
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Meng Yuan
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Lina Jiang
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Bo Sun
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Daijing Zhang
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Yun Shao
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Anqi Liu
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Xueqing Liu
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
| | - Jianhui Ma
- College of Life Science, Henan Normal University, Xinxiang, The People's Republic of China
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36
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Zha M, Imran M, Wang Y, Xu J, Ding Y, Wang S. Transcriptome analysis revealed the interaction among strigolactones, auxin, and cytokinin in controlling the shoot branching of rice. PLANT CELL REPORTS 2019; 38:279-293. [PMID: 30689021 DOI: 10.1007/s00299-018-2361-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
Strigolactones inhibit bud growth by negatively regulating the auxin transport without changing the auxin biosynthesis and suppressing the expression of A-ARR in buds. Strigolactones (SLs) are important phytohormones associated with regulation of shoot branching in rice. Rice shoot branching is persuasively mediated by plant hormones like auxin, cytokinins (CKs) and SLs. The interactions among these hormones were diversely investigated by many researchers but remained a subject of debate. In the present study, the removal of panicle and application of subsequent synthetic SLs were used to regulate rice bud growth on node 2 (the second node from panicle) at full heading stage. The bud growth was significantly induced after panicle removal but GR24 (synthetic SLs) application inhibited it, along with variations in endogenous hormone contents in bud. RNA samples from buds were subjected to RNA sequencing through Illumina HiSeq 2000 (RNA-seq). Comparison of transcript expression levels among three treatments, viz. (1) intact (Co), (2) removed panicle (RP) and (3) RP combined with synthetic SL GR24 (GR) revealed the involvement of numerous genes associated with hormone signal transduction. GR24 supply minimized the RP-induced enhancement of auxin early response genes, independent of ARF. CK signal transduction was also induced by RP, but type-A ARR were the only genes responding to GR without any other CK signal associated genes. Additionally, RP and GR can also modulate auxin transport and CK degradation by regulating the genes' expression involved in the biosynthesis of flavonoid, phenylpropanoid and benzoxazinoid. Contemplating the results obtained so far, it is possible to open new vistas of research to reveal the interactions among SLs, auxin and CK in controlling the shoot branching of rice.
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Affiliation(s)
- M Zha
- Agronomy College, Nanjing Agricultural University, Nanjing, People's Republic of China
- College of Biology and Environmental Sciences, Jishou University, Jishou, 416000, People's Republic of China
| | - M Imran
- Department of Soil and Environmental Sciences, University College of Agriculture, University of Sargodha, Sargodha, 40100, Pakistan
| | - Y Wang
- Agronomy College, Nanjing Agricultural University, Nanjing, People's Republic of China
- College of Biology and Environmental Sciences, Jishou University, Jishou, 416000, People's Republic of China
| | - J Xu
- Agronomy College, Nanjing Agricultural University, Nanjing, People's Republic of China
- Forest and Fruit Tree Institute, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, People's Republic of China
| | - Y Ding
- Agronomy College, Nanjing Agricultural University, Nanjing, People's Republic of China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, People's Republic of China
| | - Shaohua Wang
- Agronomy College, Nanjing Agricultural University, Nanjing, People's Republic of China.
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, People's Republic of China.
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37
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Bowman JL, Briginshaw LN, Fisher TJ, Flores-Sandoval E. Something ancient and something neofunctionalized-evolution of land plant hormone signaling pathways. CURRENT OPINION IN PLANT BIOLOGY 2019; 47:64-72. [PMID: 30339930 DOI: 10.1016/j.pbi.2018.09.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/13/2018] [Accepted: 09/25/2018] [Indexed: 06/08/2023]
Abstract
The evolution of land plants from a charophycean algal ancestor was accompanied by an increased diversity of regulatory networks, including signaling pathways mediating cellular communication within plants and between plants and the environment. Canonical land plant hormone signaling pathways were originally identified in angiosperms, and comparative studies in basal taxa show that they have been assembled from both ancient and newly evolved components, both before and during land plant evolution. In this review we present our current understanding, and highlight several uncertainties, of the evolution of hormone signaling pathways, focusing on the biosynthetic pathways generating putative ligands and the downstream perception and signaling pathways often leading to transcriptional responses.
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Affiliation(s)
- John L Bowman
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC 3800, Australia.
| | - Liam N Briginshaw
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Tom J Fisher
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC 3800, Australia
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38
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Hönig M, Plíhalová L, Husičková A, Nisler J, Doležal K. Role of Cytokinins in Senescence, Antioxidant Defence and Photosynthesis. Int J Mol Sci 2018; 19:E4045. [PMID: 30558142 PMCID: PMC6321018 DOI: 10.3390/ijms19124045] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/05/2018] [Accepted: 12/12/2018] [Indexed: 01/13/2023] Open
Abstract
Cytokinins modulate a number of important developmental processes, including the last phase of leaf development, known as senescence, which is associated with chlorophyll breakdown, photosynthetic apparatus disintegration and oxidative damage. There is ample evidence that cytokinins can slow down all these senescence-accompanying changes. Here, we review relationships between the various mechanisms of action of these regulatory molecules. We highlight their connection to photosynthesis, the pivotal process that generates assimilates, however may also lead to oxidative damage. Thus, we also focus on cytokinin induction of protective responses against oxidative damage. Activation of antioxidative enzymes in senescing tissues is described as well as changes in the levels of naturally occurring antioxidative compounds, such as phenolic acids and flavonoids, in plant explants. The main goal of this review is to show how the biological activities of cytokinins may be related to their chemical structure. New links between molecular aspects of natural cytokinins and their synthetic derivatives with antisenescent properties are described. Structural motifs in cytokinin molecules that may explain why these molecules play such a significant regulatory role are outlined.
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Affiliation(s)
- Martin Hönig
- 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.
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Lucie Plíhalová
- 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.
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Alexandra Husičková
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Jaroslav Nisler
- 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.
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
| | - Karel Doležal
- 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.
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic.
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39
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Han S, Cho H, Noh J, Qi J, Jung HJ, Nam H, Lee S, Hwang D, Greb T, Hwang I. BIL1-mediated MP phosphorylation integrates PXY and cytokinin signalling in secondary growth. NATURE PLANTS 2018; 4:605-614. [PMID: 29988154 DOI: 10.1038/s41477-018-0180-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 05/17/2018] [Indexed: 05/03/2023]
Abstract
Vascular cambium proliferation in plants is crucial for the generation of vascular tissues and for mechanical strength. Phytohormones and mobile peptides are key regulators of vascular cambial activity during secondary growth; however, the signalling cross-talk underlying their coordinated action is largely unknown. Here, we reveal that BIN2-LIKE 1 (BIL1), a glycogen synthase kinase 3, integrates the PHLOEM INTERCALATED WITH XYLEM/tracheary element differentiation inhibitory factor (TDIF) RECEPTOR (PXY/TDR) module into MONOPTEROS/AUXIN RESPONSE FACTOR 5 (MP/ARF5) transcription factor action during secondary growth. BIL1-mediated phosphorylation of MP/ARF5 enhances its negative effect on vascular cambial activity, which upregulates the negative regulators of cytokinin signalling ARABIDOPSIS RESPONSE REGULATOR 7 (ARR7) and ARR15. PXY/TDR inhibits BIL1 activity, which attenuates the effect of MP/ARF5 on ARR7 and ARR15 expression, thus increasing vascular cambial activity. Together, these results suggest that BIL1 is a key mediator that links peptide signalling with auxin-cytokinin signalling for the maintenance of cambial activity.
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Affiliation(s)
- Soeun Han
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Hyunwoo Cho
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Jaegyun Noh
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Jiyan Qi
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Hee-Jung Jung
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Korea
| | - Heejae Nam
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Seungchul Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Daehee Hwang
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Korea
| | - Thomas Greb
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Ildoo Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea.
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40
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Xie M, Chen H, Huang L, O'Neil RC, Shokhirev MN, Ecker JR. A B-ARR-mediated cytokinin transcriptional network directs hormone cross-regulation and shoot development. Nat Commun 2018; 9:1604. [PMID: 29686312 PMCID: PMC5913131 DOI: 10.1038/s41467-018-03921-6] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 03/22/2018] [Indexed: 11/08/2022] Open
Abstract
Cytokinin fulfills its diverse roles in planta through a series of transcriptional responses. We identify the in vivo DNA binding site profiles for three genetically redundant type-B ARABIDOPSIS RESPONSE REGULATORS (B-ARRs): ARR1, ARR10, and ARR12. The expression and genome-wide DNA binding locations of the three B-ARRs extensively overlap. Constructing a primary cytokinin response transcriptional network reveals a recurring theme of widespread cross-regulation between the components of the cytokinin pathway and other plant hormone pathways. The B-ARRs are found to have similar DNA binding motifs, though sequences flanking the core motif were degenerate. Cytokinin treatments amalgamate the three different B-ARRs motifs to identical DNA binding signatures (AGATHY, H(a/t/c), Y(t/c)) which suggests cytokinin may regulate binding activity of B-ARR family members. Furthermore, we find that WUSCHEL, a key gene required for apical meristem maintenance, is a cytokinin-dependent B-ARR target gene, demonstrating the importance of the cytokinin transcription factor network in shoot development.
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Affiliation(s)
- Mingtang Xie
- Plant Biology Laboratory, and Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Hongyu Chen
- Department of Computer Science, Dartmouth College, Hanover, NH, 03755, USA
| | - Ling Huang
- The Razavi Newman Integrative Genomics and Bioinformatics Core Facility, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Ryan C O'Neil
- Plant Biology Laboratory, and Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Bioinformatics Program, University of California at San Diego, La Jolla, CA, 92093, USA
| | - Maxim N Shokhirev
- The Razavi Newman Integrative Genomics and Bioinformatics Core Facility, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Joseph R Ecker
- Plant Biology Laboratory, and Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
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41
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Wang WF, Chen P, Lv J, Chen L, Sun YH. Transcriptomic analysis of topping-induced axillary shoot outgrowth in Nicotiana tabacum. Gene 2018; 646:169-180. [PMID: 29292191 DOI: 10.1016/j.gene.2017.12.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/11/2017] [Accepted: 12/27/2017] [Indexed: 12/16/2022]
Abstract
Topping is an important agronomic practice that significantly impacts the yield of various crop plants. Topping and the regulation of axillary shoot outgrowth are common agronomic practices in tobacco. However, the effects of topping on gene expression in tobacco remain unknown. We applied the Illumina HiSeq™ 2000 platform and analyzed differentially expressed genes (DEGs) from untopped and topped plants to study the global changes in gene expression in response to topping. We found that the number of DEGs varied from 7609 to 18,770 based on the reads per kilobase per million mapped reads (RPKM) values. The Gene Ontology (GO) enrichment analysis revealed that the cellular carbohydrate metabolic process and the disaccharide metabolic process, which may contribute to starch accumulation and stress/defense, were overrepresented terms for the DEGs. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that many DEGs were involved in starch and sucrose metabolism, glycolysis/gluconeogenesis, pyruvate metabolism, and plant hormone signal transduction, among other processes. The knowledge gained will improve our understanding of the processes of axillary shoot formation and enlargement at the transcriptional level. This study lays a solid foundation for future studies on molecular mechanisms underlying the growth of axillary shoots.
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Affiliation(s)
- Wei-Feng Wang
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Peng Chen
- College of Plant Protection, China Agricultural University, Beijing 100193, China.
| | - Jing Lv
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
| | - Lei Chen
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Yu-He Sun
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China.
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42
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Abstract
The phytohormone cytokinin plays diverse roles in plant development, influencing many agriculturally important processes, including growth, nutrient responses and the response to biotic and abiotic stresses. Cytokinin levels in plants are regulated by biosynthesis and inactivation pathways. Cytokinins are perceived by membrane-localized histidine-kinase receptors and are transduced through a His-Asp phosphorelay to activate a family of transcription factors in the nucleus. Here, and in the accompanying poster, we summarize the current understanding of cytokinin metabolism, transport and signaling, and discuss how this phytohormone regulates changes in gene expression to mediate its pleiotropic effects.
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Affiliation(s)
- Joseph J Kieber
- University of North Carolina, Biology Department, Chapel Hill, NC 27599-3280, USA
| | - G Eric Schaller
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755, USA
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43
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Numan M, Bashir S, Khan Y, Mumtaz R, Shinwari ZK, Khan AL, Khan A, Al-Harrasi A. Plant growth promoting bacteria as an alternative strategy for salt tolerance in plants: A review. Microbiol Res 2018; 209:21-32. [PMID: 29580619 DOI: 10.1016/j.micres.2018.02.003] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/31/2018] [Accepted: 02/10/2018] [Indexed: 11/26/2022]
Abstract
Approximately 5.2 billion hectare agriculture land are affected by erosion, salinity and soil degradation. Salinity stress has significantly affecting the fertile lands, and therefore possesses a huge impact on the agriculture and economy of a country. Salt stress has severe effects on the growth and development of plants as well as reducing its yield. Plants are inherently equipped with stress tolerance ability to responds the specific type of stress. Plants retained specific mechanisms for salt stress mitigation, such as hormonal stimulation, ion exchange, antioxidant enzymes and activation of signaling cascades on their metabolic and genetic frontiers that sooth the stressed condition. Additional to the plant inherent mechanisms, certain plant growth promoting bacteria (PGPB) also have specialized mechanism that play key role for salt stress tolerance and plant growth promotion. These bacteria triggers plants to produce different plant growth hormones like auxin, cytokinine and gibberellin as well as volatile organic compounds. These bacteria also produces growth regulators like siderophore, which fix nitrogen, solubilize organic and inorganic phosphate. Considering the importance of PGPB in compensation of salt tolerance in plants, the present study has reviewed the different aspect and mechanism of bacteria that play key role in promoting plants growth and yield. It can be concluded that PGPB can be used as a cost effective and economical tool for salinity tolerance and growth promotion in plants.
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Affiliation(s)
- Muhammad Numan
- Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan; UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa, P.O. Box 33, Birkatal Al Mauz, Nizwa 616, Oman.
| | - Samina Bashir
- Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
| | - Yasmin Khan
- Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
| | - Roqayya Mumtaz
- Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
| | - Zabta Khan Shinwari
- Qarshi Research International and Vice Chancellor of Qarshi University, Lahore, Pakistan.
| | - Abdul Latif Khan
- UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa, P.O. Box 33, Birkatal Al Mauz, Nizwa 616, Oman
| | - Ajmal Khan
- UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa, P.O. Box 33, Birkatal Al Mauz, Nizwa 616, Oman.
| | - Ahmed Al-Harrasi
- UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa, P.O. Box 33, Birkatal Al Mauz, Nizwa 616, Oman.
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44
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Roy S. Joseph J. Kieber. THE PLANT CELL 2018; 30:255-257. [PMID: 29434046 PMCID: PMC5868696 DOI: 10.1105/tpc.18.00110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Sonali Roy
- Noble Research InstituteArdmore, Oklahoma
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45
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Pernisova M, Grochova M, Konecny T, Plackova L, Harustiakova D, Kakimoto T, Heisler MG, Novak O, Hejatko J. Cytokinin signalling regulates organ identity via AHK4 receptor in Arabidopsis. Development 2018; 145:dev.163907. [DOI: 10.1242/dev.163907] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 06/22/2018] [Indexed: 01/19/2023]
Abstract
Mutual interactions of the phytohormones cytokinins and auxin determine root or shoot identity during postembryonic de novo organogenesis in plants. However, our understanding to the role of hormonal metabolism and perception during early stages of cell fate reprograming is still elusive.
In the hypocotyl explant assay, auxin activated root formation while cytokinins mediated early loss of the root identity, primordia disorganization and initiation of shoot development. Exogenous but also endogenous cytokinins influenced the initiation of newly formed organs as well as the pace of organ developmental sequence. The process of de novo shoot apical meristem establishment was accompanied by accumulation of endogenous cytokinins, differential regulation of genes for individual cytokinin receptors, strong activation of AHK4-mediated signalling and induction of shoot-specific homeodomain regulator WUSCHEL. The latter associated with upregulation of isopentenyladenine-type cytokinins, revealing higher shoot-forming potential when compared with trans-zeatin. Moreover, AHK4-controlled cytokinin signalling negatively regulated root stem cell organizer WUSCHEL RELATED HOMEOBOX 5 in the root quiescent centre. We propose an important role of endogenous cytokinin biosynthesis and AHK4-mediated cytokinin signalling in the control of de novo induced organ identity.
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Affiliation(s)
- Marketa Pernisova
- CEITEC - Central European Institute of Technology and Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Martina Grochova
- CEITEC - Central European Institute of Technology and Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Tomas Konecny
- CEITEC - Central European Institute of Technology and Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Lenka Plackova
- Laboratory of Growth Regulators, CRH, Institute of Experimental Botany AS CR and Faculty of Science of Palacký University, Olomouc, Czech Republic
| | - Danka Harustiakova
- Institute of Biostatistics and Analyses, Faculty of Medicine and Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Tatsuo Kakimoto
- Department of Biological Science, Graduate School of Science, Osaka University, Osaka, Japan
| | | | - Ondrej Novak
- Laboratory of Growth Regulators, CRH, Institute of Experimental Botany AS CR and Faculty of Science of Palacký University, Olomouc, Czech Republic
| | - Jan Hejatko
- CEITEC - Central European Institute of Technology and Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
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46
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SEKI N, TANIGAKI Y, YOSHIDA A, FUKUDA H. Spatiotemporal Analysis of Localized Circadian Arrhythmias in Plant Roots. ACTA ACUST UNITED AC 2018. [DOI: 10.2525/ecb.56.93] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Naoki SEKI
- Graduate School of Engineering, Osaka Prefecture University
| | | | | | - Hirokazu FUKUDA
- Graduate School of Engineering, Osaka Prefecture University
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology
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47
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Sharan A, Soni P, Nongpiur RC, Singla-Pareek SL, Pareek A. Mapping the 'Two-component system' network in rice. Sci Rep 2017; 7:9287. [PMID: 28839155 PMCID: PMC5571105 DOI: 10.1038/s41598-017-08076-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/06/2017] [Indexed: 01/20/2023] Open
Abstract
Two-component system (TCS) in plants is a histidine to aspartate phosphorelay based signaling system. Rice genome has multifarious TCS signaling machinery comprising of 11 histidine kinases (OsHKs), 5 histidine phosphotransferases (OsHPTs) and 36 response regulators (OsRRs). However, how these TCS members interact with each other and comprehend diverse signaling cascades remains unmapped. Using a highly stringent yeast two-hybrid (Y2H) platform and extensive in planta bimolecular fluorescence complementation (BiFC) assays, distinct arrays of interaction between various TCS proteins have been identified in the present study. Based on these results, an interactome map of TCS proteins has been assembled. This map clearly shows a cross talk in signaling, mediated by different sensory OsHKs. It also highlights OsHPTs as the interaction hubs, which interact with OsRRs, mostly in a redundant fashion. Remarkably, interactions between type-A and type-B OsRRs have also been revealed for the first time. These observations suggest that feedback regulation by type-A OsRRs may also be mediated by interference in signaling at the level of type-B OsRRs, in addition to OsHPTs, as known previously. The interactome map presented here provides a starting point for in-depth molecular investigations for signal(s) transmitted by various TCS modules into diverse biological processes.
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Affiliation(s)
- Ashutosh Sharan
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Praveen Soni
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Ramsong Chantre Nongpiur
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Sneh L Singla-Pareek
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
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Liu B, De Storme N, Geelen D. Cold interferes with male meiotic cytokinesis in Arabidopsis thaliana independently of the AHK2/3-AHP2/3/5 cytokinin signaling module. Cell Biol Int 2017; 41:879-889. [PMID: 28618065 DOI: 10.1002/cbin.10805] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/11/2017] [Indexed: 12/21/2022]
Abstract
Previously we have shown that low temperature stress in Arabidopsis causes defects in microtubule organization and cytokinesis in male meiocytes, which leads to the formation of diploid pollen. Because cytokinin (CK) mediates multiple physiological responses to cold stress, we investigated whether CK signaling is involved in cold-induced diploid pollen formation. To this end, we monitored male sporogenesis in a series of mutants defective in CK metabolism and signalling. Arabidopsis plants with altered CK homeostasis, that is, the ahk2-2 ahk3-3 double and the ahp2-1 ahp3 ahp5-2 triple mutant, were cold sensitive and displayed similar defective male meiotic cytokinesis as wild type plants upon cold stress. These findings demonstrate that the AHK2/3-AHP2/3/5 CK-signaling module is not required for cold-induced ploidy stability of male gamete in Arabidopsis. Cytological analysis further revealed that the cold-induced cytokinesis defects in the ahk2-2 ahk3-3 mutant correlated with irregular organization of the radial microtubule array (RMA) in tetrad microspores at the end of male meiosis. Contrary to the ahk and ahp mutants, Arabidopsis plants defective for ARR1, a downstream target of ahk and ahp mediated CK signalling, displayed higher cold-tolerance of male meiotic cytokinesis program. We here suggest that the transcription regulator ARR1 may act independently from the CK AHK2/3-AHP2/3/5 signaling module in conveying the cold response to male meiocytes.
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Affiliation(s)
- Bing Liu
- Faculty of Bioscience Engineering, Department of Plant Production, University of Ghent, Ghent, 9000, Belgium
| | - Nico De Storme
- Faculty of Bioscience Engineering, Department of Plant Production, University of Ghent, Ghent, 9000, Belgium
| | - Danny Geelen
- Faculty of Bioscience Engineering, Department of Plant Production, University of Ghent, Ghent, 9000, Belgium
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Bielach A, Hrtyan M, Tognetti VB. Plants under Stress: Involvement of Auxin and Cytokinin. Int J Mol Sci 2017; 18:E1427. [PMID: 28677656 PMCID: PMC5535918 DOI: 10.3390/ijms18071427] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023] Open
Abstract
Plant growth and development are critically influenced by unpredictable abiotic factors. To survive fluctuating changes in their environments, plants have had to develop robust adaptive mechanisms. The dynamic and complementary actions of the auxin and cytokinin pathways regulate a plethora of developmental processes, and their ability to crosstalk makes them ideal candidates for mediating stress-adaptation responses. Other crucial signaling molecules responsible for the tremendous plasticity observed in plant morphology and in response to abiotic stress are reactive oxygen species (ROS). Proper temporal and spatial distribution of ROS and hormone gradients is crucial for plant survival in response to unfavorable environments. In this regard, the convergence of ROS with phytohormone pathways acts as an integrator of external and developmental signals into systemic responses organized to adapt plants to their environments. Auxin and cytokinin signaling pathways have been studied extensively. Nevertheless, we do not yet understand the impact on plant stress tolerance of the sophisticated crosstalk between the two hormones. Here, we review current knowledge on the function of auxin and cytokinin in redirecting growth induced by abiotic stress in order to deduce their potential points of crosstalk.
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Affiliation(s)
- Agnieszka Bielach
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Czech 62500, Brno, Czech Republic.
| | - Monika Hrtyan
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Czech 62500, Brno, Czech Republic.
| | - Vanesa B Tognetti
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, Czech 62500, Brno, Czech Republic.
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50
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Cytokinin induces genome-wide binding of the type-B response regulator ARR10 to regulate growth and development in Arabidopsis. Proc Natl Acad Sci U S A 2017; 114:E5995-E6004. [PMID: 28673986 DOI: 10.1073/pnas.1620749114] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The plant hormone cytokinin affects a diverse array of growth and development processes and responses to the environment. How a signaling molecule mediates such a diverse array of outputs and how these response pathways are integrated with other inputs remain fundamental questions in plant biology. To this end, we characterized the transcriptional network initiated by the type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs) that mediate the cytokinin primary response, making use of chromatin immunoprecipitation sequencing (ChIP-seq), protein-binding microarrays, and transcriptomic approaches. By ectopic overexpression of ARR10, Arabidopsis lines hypersensitive to cytokinin were generated and used to clarify the role of cytokinin in regulation of various physiological responses. ChIP-seq was used to identify the cytokinin-dependent targets for ARR10, thereby defining a crucial link between the cytokinin primary-response pathway and the transcriptional changes that mediate physiological responses to this phytohormone. Binding of ARR10 was induced by cytokinin with binding sites enriched toward the transcriptional start sites for both induced and repressed genes. Three type-B ARR DNA-binding motifs, determined by use of protein-binding microarrays, were enriched at ARR10 binding sites, confirming their physiological relevance. WUSCHEL was identified as a direct target of ARR10, with its cytokinin-enhanced expression resulting in enhanced shooting in tissue culture. Results from our analyses shed light on the physiological role of the type-B ARRs in regulating the cytokinin response, mechanism of type-B ARR activation, and basis by which cytokinin regulates diverse aspects of growth and development as well as responses to biotic and abiotic factors.
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