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Bhattacharjee O, Raul B, Ghosh A, Bhardwaj A, Bandyopadhyay K, Sinharoy S. Nodule INception-independent epidermal events lead to bacterial entry during nodule development in peanut (Arachis hypogaea). THE NEW PHYTOLOGIST 2022; 236:2265-2281. [PMID: 36098671 DOI: 10.1111/nph.18483] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
Legumes can host nitrogen-fixing rhizobia inside root nodules. In model legumes, rhizobia enter via infection threads (ITs) and develop nodules in which the infection zone contains a mixture of infected and uninfected cells. Peanut (Arachis hypogaea) diversified from model legumes c. 50-55 million years ago. Rhizobia enter through 'cracks' to form nodules in peanut roots where cells of the infection zone are uniformly infected. Phylogenomic studies have indicated symbiosis as a labile trait in peanut. These atypical features prompted us to investigate the molecular mechanism of peanut nodule development. Combining cell biology, genetics and genomic tools, we visualized the status of hormonal signaling in peanut nodule primordia. Moreover, we dissected the signaling modules of Nodule INception (NIN), a master regulator of both epidermal infection and cortical organogenesis. Cytokinin signaling operates in a broad zone, from the epidermis to the pericycle inside nodule primordia, while auxin signaling is narrower and focused. Nodule INception is involved in nodule organogenesis, but not in crack entry. Nodulation Pectate Lyase, which remodels cell walls during IT formation, is not required. By contrast, Nodule enhanced Glycosyl Hydrolases (AhNGHs) are recruited for cell wall modification during crack entry. While hormonal regulation is conserved, the function of the NIN signaling modules is diversified in peanut.
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Affiliation(s)
- Oindrila Bhattacharjee
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India
- Amity University Haryana, Amity Education Valley, Panchgaon, Manesar, Haryana, 122412, India
| | - Bikash Raul
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Amit Ghosh
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Akanksha Bhardwaj
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Kaustav Bandyopadhyay
- Amity University Haryana, Amity Education Valley, Panchgaon, Manesar, Haryana, 122412, India
| | - Senjuti Sinharoy
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India
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2
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Chu X, Su H, Hayashi S, Gresshoff PM, Ferguson BJ. Spatiotemporal changes in gibberellin content are required for soybean nodulation. THE NEW PHYTOLOGIST 2022; 234:479-493. [PMID: 34870861 DOI: 10.1111/nph.17902] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 11/24/2021] [Indexed: 06/13/2023]
Abstract
The plant hormone gibberellin (GA) is required at different stages of legume nodule development, with its spatiotemporal distribution tightly regulated. Transcriptomic and bioinformatic analyses established that several key GA biosynthesis and catabolism enzyme encoding genes are critical to soybean (Glycine max) nodule formation. We examined the expression of several GA oxidase genes and used a Förster resonance energy transfer-based GA biosensor to determine the bioactive GA content of roots inoculated with DsRed-labelled Bradyrhizobium diazoefficiens. We manipulated the level of GA by genetically disrupting the expression of GA oxidase genes. Moreover, exogenous treatment of soybean roots with GA3 induced the expression of key nodulation genes and altered infection thread and nodule phenotypes. GmGA20ox1a, GmGA3ox1a, and GmGA2ox1a are upregulated in soybean roots inoculated with compatible B. diazoefficiens. GmGA20ox1a expression is predominately localized to the transient meristem of soybean nodules and coincides with the spatiotemporal distribution of bioactive GA occurring throughout nodule organogenesis. GmGA2ox1a exhibits a nodule vasculature-specific expression pattern, whereas GmGA3ox1a can be detected throughout the nodule and root. Disruptions in the level of GA resulted in aberrant rhizobia infection and reduced nodule numbers. Collectively, our results establish a central role for GAs in root hair infection by symbiotic rhizobia and in nodule organogenesis.
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Affiliation(s)
- Xitong Chu
- Integrative Legume Research Group, School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Brisbane, Qld, 4072, Australia
| | - Huanan Su
- Integrative Legume Research Group, School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Brisbane, Qld, 4072, Australia
- National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Satomi Hayashi
- Integrative Legume Research Group, School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Brisbane, Qld, 4072, Australia
- Centre for Agriculture and Biocommodities, Queensland University of Technology, Brisbane, Qld, 4000, Australia
| | - Peter M Gresshoff
- Integrative Legume Research Group, School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Brisbane, Qld, 4072, Australia
| | - Brett J Ferguson
- Integrative Legume Research Group, School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Brisbane, Qld, 4072, Australia
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3
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Triozzi PM, Irving TB, Schmidt HW, Keyser ZP, Chakraborty S, Balmant K, Pereira WJ, Dervinis C, Mysore KS, Wen J, Ané JM, Kirst M, Conde D. Spatiotemporal cytokinin response imaging and ISOPENTENYLTRANSFERASE 3 function in Medicago nodule development. PLANT PHYSIOLOGY 2022; 188:560-575. [PMID: 34599592 PMCID: PMC8774767 DOI: 10.1093/plphys/kiab447] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Most legumes can establish a symbiotic association with soil rhizobia that trigger the development of root nodules. These nodules host the rhizobia and allow them to fix nitrogen efficiently. The perception of bacterial lipo-chitooligosaccharides (LCOs) in the epidermis initiates a signaling cascade that allows rhizobial intracellular infection in the root and de-differentiation and activation of cell division that gives rise to the nodule. Thus, nodule organogenesis and rhizobial infection need to be coupled in space and time for successful nodulation. The plant hormone cytokinin (CK) contributes to the coordination of this process, acting as an essential positive regulator of nodule organogenesis. However, the temporal regulation of tissue-specific CK signaling and biosynthesis in response to LCOs or Sinorhizobium meliloti inoculation in Medicago truncatula remains poorly understood. In this study, using a fluorescence-based CK sensor (pTCSn::nls:tGFP), we performed a high-resolution tissue-specific temporal characterization of the sequential activation of CK response during root infection and nodule development in M. truncatula after inoculation with S. meliloti. Loss-of-function mutants of the CK-biosynthetic gene ISOPENTENYLTRANSFERASE 3 (IPT3) showed impairment of nodulation, suggesting that IPT3 is required for nodule development in M. truncatula. Simultaneous live imaging of pIPT3::nls:tdTOMATO and the CK sensor showed that IPT3 induction in the pericycle at the base of nodule primordium contributes to CK biosynthesis, which in turn promotes expression of positive regulators of nodule organogenesis in M. truncatula.
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Affiliation(s)
- Paolo M Triozzi
- School of Forest, Fisheries and Geomatics Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Thomas B Irving
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Henry W Schmidt
- School of Forest, Fisheries and Geomatics Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Zachary P Keyser
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Sanhita Chakraborty
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Kelly Balmant
- School of Forest, Fisheries and Geomatics Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Wendell J Pereira
- School of Forest, Fisheries and Geomatics Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Christopher Dervinis
- School of Forest, Fisheries and Geomatics Sciences, University of Florida, Gainesville, Florida 32611, USA
| | | | - Jiangqi Wen
- Noble Research Institute, Ardmore, Oklahoma 73401, USA
| | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Department of Agronomy, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Matias Kirst
- School of Forest, Fisheries and Geomatics Sciences, University of Florida, Gainesville, Florida 32611, USA
- Genetics Institute, University of Florida, Gainesville, Florida 32611, USA
| | - Daniel Conde
- School of Forest, Fisheries and Geomatics Sciences, University of Florida, Gainesville, Florida 32611, USA
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Thibivilliers S, Libault M. Enhancing Our Understanding of Plant Cell-to-Cell Interactions Using Single-Cell Omics. FRONTIERS IN PLANT SCIENCE 2021; 12:696811. [PMID: 34421948 PMCID: PMC8375048 DOI: 10.3389/fpls.2021.696811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/07/2021] [Indexed: 05/05/2023]
Abstract
Plants are composed of cells that physically interact and constantly adapt to their environment. To reveal the contribution of each plant cells to the biology of the entire organism, their molecular, morphological, and physiological attributes must be quantified and analyzed in the context of the morphology of the plant organs. The emergence of single-cell/nucleus omics technologies now allows plant biologists to access different modalities of individual cells including their epigenome and transcriptome to reveal the unique molecular properties of each cell composing the plant and their dynamic regulation during cell differentiation and in response to their environment. In this manuscript, we provide a perspective regarding the challenges and strategies to collect plant single-cell biological datasets and their analysis in the context of cellular interactions. As an example, we provide an analysis of the transcriptional regulation of the Arabidopsis genes controlling the differentiation of the root hair cells at the single-cell level. We also discuss the perspective of the use of spatial profiling to complement existing plant single-cell omics.
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Affiliation(s)
| | - Marc Libault
- Department of Agronomy and Horticulture, Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, United States
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Biosensors: A Sneak Peek into Plant Cell's Immunity. Life (Basel) 2021; 11:life11030209. [PMID: 33800034 PMCID: PMC7999283 DOI: 10.3390/life11030209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/23/2021] [Accepted: 03/03/2021] [Indexed: 12/26/2022] Open
Abstract
Biosensors are indispensable tools to understand a plant’s immunity as its spatiotemporal dimension is key in withstanding complex plant immune signaling. The diversity of genetically encoded biosensors in plants is expanding, covering new analytes with ever higher sensitivity and robustness, but their assortment is limited in some respects, such as their use in following biotic stress response, employing more than one biosensor in the same chassis, and their implementation into crops. In this review, we focused on the available biosensors that encompass these aspects. We show that in vivo imaging of calcium and reactive oxygen species is satisfactorily covered with the available genetically encoded biosensors, while on the other hand they are still underrepresented when it comes to imaging of the main three hormonal players in the immune response: salicylic acid, ethylene and jasmonic acid. Following more than one analyte in the same chassis, upon one or more conditions, has so far been possible by using the most advanced genetically encoded biosensors in plants which allow the monitoring of calcium and the two main hormonal pathways involved in plant development, auxin and cytokinin. These kinds of biosensor are also the most evolved in crops. In the last section, we examine the challenges in the use of biosensors and demonstrate some strategies to overcome them.
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Dolgikh EA, Kusakin PG, Kitaeva AB, Tsyganova AV, Kirienko AN, Leppyanen IV, Dolgikh AV, Ilina EL, Demchenko KN, Tikhonovich IA, Tsyganov VE. Mutational analysis indicates that abnormalities in rhizobial infection and subsequent plant cell and bacteroid differentiation in pea (Pisum sativum) nodules coincide with abnormal cytokinin responses and localization. ANNALS OF BOTANY 2020; 125:905-923. [PMID: 32198503 PMCID: PMC7218816 DOI: 10.1093/aob/mcaa022] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 02/26/2020] [Indexed: 05/14/2023]
Abstract
BACKGROUND AND AIMS Recent findings indicate that Nod factor signalling is tightly interconnected with phytohormonal regulation that affects the development of nodules. Since the mechanisms of this interaction are still far from understood, here the distribution of cytokinin and auxin in pea (Pisum sativum) nodules was investigated. In addition, the effect of certain mutations blocking rhizobial infection and subsequent plant cell and bacteroid differentiation on cytokinin distribution in nodules was analysed. METHODS Patterns of cytokinin and auxin in pea nodules were profiled using both responsive genetic constructs and antibodies. KEY RESULTS In wild-type nodules, cytokinins were found in the meristem, infection zone and apical part of the nitrogen fixation zone, whereas auxin localization was restricted to the meristem and peripheral tissues. We found significantly altered cytokinin distribution in sym33 and sym40 pea mutants defective in IPD3/CYCLOPS and EFD transcription factors, respectively. In the sym33 mutants impaired in bacterial accommodation and subsequent nodule differentiation, cytokinin localization was mostly limited to the meristem. In addition, we found significantly decreased expression of LOG1 and A-type RR11 as well as KNOX3 and NIN genes in the sym33 mutants, which correlated with low cellular cytokinin levels. In the sym40 mutant, cytokinins were detected in the nodule infection zone but, in contrast to the wild type, they were absent in infection droplets. CONCLUSIONS In conclusion, our findings suggest that enhanced cytokinin accumulation during the late stages of symbiosis development may be associated with bacterial penetration into the plant cells and subsequent plant cell and bacteroid differentiation.
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Affiliation(s)
- Elena A Dolgikh
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
| | - Pyotr G Kusakin
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
| | - Anna B Kitaeva
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
| | - Anna V Tsyganova
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
| | - Anna N Kirienko
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
| | - Irina V Leppyanen
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
| | - Aleksandra V Dolgikh
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
- Saint Petersburg State University, Department of Genetics and Biotechnology, Universitetskaya embankment 7–9, Saint Petersburg, Russia
| | - Elena L Ilina
- Komarov Botanical Institute, Russian Academy of Sciences, Laboratory of Cellular and Molecular Mechanisms of Plant Development, Saint Petersburg, Russia
| | - Kirill N Demchenko
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
- Komarov Botanical Institute, Russian Academy of Sciences, Laboratory of Cellular and Molecular Mechanisms of Plant Development, Saint Petersburg, Russia
| | - Igor A Tikhonovich
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
- Saint Petersburg State University, Department of Genetics and Biotechnology, Universitetskaya embankment 7–9, Saint Petersburg, Russia
| | - Viktor E Tsyganov
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Saint Petersburg, Russia
- Saint Petersburg Scientific Center Russian Academy of Sciences, Universitetskaya embankment 5, Saint Petersburg, Russia
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Ng JLP, Welvaert A, Wen J, Chen R, Mathesius U. The Medicago truncatula PIN2 auxin transporter mediates basipetal auxin transport but is not necessary for nodulation. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1562-1573. [PMID: 31738415 DOI: 10.1093/jxb/erz510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
The development of root nodules leads to an increased auxin response in early nodule primordia, which is mediated by changes in acropetal auxin transport in some legumes. Here, we investigated the role of root basipetal auxin transport during nodulation. Rhizobia inoculation significantly increased basipetal auxin transport in both Medicago truncatula and Lotus japonicus. In M. truncatula, this increase was dependent on functional Nod factor signalling through NFP, NIN, and NSP2, as well as ethylene signalling through SKL. To test whether increased basipetal auxin transport is required for nodulation, we examined a loss-of-function mutant of the M. truncatula PIN2 gene. The Mtpin2 mutant exhibited a reduction in basipetal auxin transport and an agravitropic phenotype. Inoculation of Mtpin2 roots with rhizobia still led to a moderate increase in basipetal auxin transport, but the mutant nodulated normally. No clear differences in auxin response were observed during nodule development. Interestingly, inoculation of wild-type roots increased lateral root numbers, whereas inoculation of Mtpin2 mutants resulted in reduced lateral root numbers compared with uninoculated roots. We conclude that the MtPIN2 auxin transporter is involved in basipetal auxin transport, that its function is not essential for nodulation, but that it plays an important role in the control of lateral root development.
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Affiliation(s)
- Jason L P Ng
- Division of Plant Science, Research School of Biology, Australian National University, Canberra, Australia
| | - Astrid Welvaert
- Division of Plant Science, Research School of Biology, Australian National University, Canberra, Australia
| | - Jiangqi Wen
- Noble Research Institute LLC, Ardmore, OK, USA
| | - Rujin Chen
- School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Ulrike Mathesius
- Division of Plant Science, Research School of Biology, Australian National University, Canberra, Australia
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8
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Qiao Z, Zogli P, Libault M. Plant Hormones Differentially Control the Sub-Cellular Localization of Plasma Membrane Microdomains during the Early Stage of Soybean Nodulation. Genes (Basel) 2019; 10:E1012. [PMID: 31817452 PMCID: PMC6947267 DOI: 10.3390/genes10121012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/30/2019] [Accepted: 12/02/2019] [Indexed: 01/31/2023] Open
Abstract
Phytohormones regulate the mutualistic symbiotic interaction between legumes and rhizobia, nitrogen-fixing soil bacteria, notably by controlling the formation of the infection thread in the root hair (RH). At the cellular level, the formation of the infection thread is promoted by the translocation of plasma membrane microdomains at the tip of the RH. We hypothesize that phytohormones regulate the translocation of plasma membrane microdomains to regulate infection thread formation. Accordingly, we treated with hormone and hormone inhibitors transgenic soybean roots expressing fusions between the Green Fluorescent Protein (GFP) and GmFWL1 or GmFLOT2/4, two microdomain-associated proteins translocated at the tip of the soybean RH in response to rhizobia. Auxin and cytokinin treatments are sufficient to trigger or inhibit the translocation of GmFWL1 and GmFLOT2/4 to the RH tip independently of the presence of rhizobia, respectively. Unexpectedly, the application of salicylic acid, a phytohormone regulating the plant defense system, also promotes the translocation of GmFWL1 and GmFLOT2/4 to the RH tip regardless of the presence of rhizobia. These results suggest that phytohormones are playing a central role in controlling the early stages of rhizobia infection by regulating the translocation of plasma membrane microdomains. They also support the concept of crosstalk of phytohormones to control nodulation.
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Affiliation(s)
- Zhenzhen Qiao
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, USA;
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Prince Zogli
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Beadle Center, Lincoln, NE 68503, USA;
| | - Marc Libault
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Beadle Center, Lincoln, NE 68503, USA;
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9
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Soba D, Zhou B, Arrese-Igor C, Munné-Bosch S, Aranjuelo I. Physiological, Hormonal and Metabolic Responses of two Alfalfa Cultivars with Contrasting Responses to Drought. Int J Mol Sci 2019; 20:E5099. [PMID: 31618819 PMCID: PMC6829892 DOI: 10.3390/ijms20205099] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/13/2019] [Accepted: 10/14/2019] [Indexed: 12/17/2022] Open
Abstract
Alfalfa (Medicago sativa L.) is frequently constrained by environmental conditions such as drought. Within this context, it is crucial to identify the physiological and metabolic traits conferring a better performance under stressful conditions. In the current study, two alfalfa cultivars (San Isidro and Zhong Mu) with different physiological strategies were selected and subjected to water limitation conditions. Together with the physiological analyses, we proceeded to characterize the isotopic, hormone, and metabolic profiles of the different plants. According to physiological and isotopic data, Zhong Mu has a water-saver strategy, reducing water lost by closing its stomata but fixing less carbon by photosynthesis, and therefore limiting its growth under water-stressed conditions. In contrast, San Isidro has enhanced root growth to replace the water lost through transpiration due to its more open stomata, thus maintaining its biomass. Zhong Mu nodules were less able to maintain nodule N2 fixing activity (matching plant nitrogen (N) demand). Our data suggest that this cultivar-specific performance is linked to Asn accumulation and its consequent N-feedback nitrogenase inhibition. Additionally, we observed a hormonal reorchestration in both cultivars under drought. Therefore, our results showed an intra-specific response to drought at physiological and metabolic levels in the two alfalfa cultivars studied.
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Affiliation(s)
- David Soba
- Instituto de Agrobiotecnología (IdAB), Consejo Superior de Investigaciones Científicas-Gobierno de Navarra, 31006 Mutilva, Spain.
| | - Bangwei Zhou
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China.
| | - Cesar Arrese-Igor
- Department of Sciences, Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra, E-31006 Pamplona, Spain.
| | - Sergi Munné-Bosch
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain.
| | - Iker Aranjuelo
- Instituto de Agrobiotecnología (IdAB), Consejo Superior de Investigaciones Científicas-Gobierno de Navarra, 31006 Mutilva, Spain.
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Nadzieja M, Stougaard J, Reid D. A Toolkit for High Resolution Imaging of Cell Division and Phytohormone Signaling in Legume Roots and Root Nodules. FRONTIERS IN PLANT SCIENCE 2019; 10:1000. [PMID: 31428118 PMCID: PMC6688427 DOI: 10.3389/fpls.2019.01000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/17/2019] [Indexed: 05/22/2023]
Abstract
Legume plants benefit from a nitrogen-fixing symbiosis in association with rhizobia hosted in specialized root nodules. Formation of root nodules is initiated by de novo organogenesis and coordinated infection of these developing lateral root organs by rhizobia. Both bacterial infection and nodule organogenesis involve cell cycle activation and regulation by auxin and cytokinin is tightly integrated in the process. To characterize the hormone dynamics and cell division patterns with cellular resolution during nodulation, sensitive and specific sensors suited for imaging of multicellular tissues are required. Here we report a modular toolkit, optimized in the model legume Lotus japonicus, for use in legume roots and root nodules. This toolkit includes synthetic transcriptional reporters for auxin and cytokinin, auxin accumulation sensors and cell cycle progression markers optimized for fluorescent and bright field microscopy. The developed vectors allow for efficient one-step assembly of multiple units using the GoldenGate cloning system. Applied together with a fluorescence-compatible clearing approach, these reporters improve imaging depth and facilitate fluorescence examination in legume roots. We additionally evaluate the utility of the dynamic gravitropic root response in altering the timing and location of auxin accumulation and nodule emergence. We show that alteration of auxin distribution in roots allows for preferential nodule emergence at the outer side of the bend corresponding to a region of high auxin signaling capacity. The presented tools and procedures open new possibilities for comparative mutant studies and for developing a more comprehensive understanding of legume-rhizobia interactions.
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11
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Demina IV, Maity PJ, Nagchowdhury A, Ng JLP, van der Graaff E, Demchenko KN, Roitsch T, Mathesius U, Pawlowski K. Accumulation of and Response to Auxins in Roots and Nodules of the Actinorhizal Plant Datisca glomerata Compared to the Model Legume Medicago truncatula. FRONTIERS IN PLANT SCIENCE 2019; 10:1085. [PMID: 31608077 PMCID: PMC6773980 DOI: 10.3389/fpls.2019.01085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 08/09/2019] [Indexed: 05/13/2023]
Abstract
Actinorhizal nodules are structurally different from legume nodules and show a greater similarity to lateral roots. Because of the important role of auxins in lateral root and nodule formation, auxin profiles were examined in roots and nodules of the actinorhizal species Datisca glomerata and the model legume Medicago truncatula. The auxin response in roots and nodules of both species was analyzed in transgenic root systems expressing a beta-glucuronidase gene under control of the synthetic auxin-responsive promoter DR5. The effects of two different auxin on root development were compared for both species. The auxin present in nodules at the highest levels was phenylacetic acid (PAA). No differences were found between the concentrations of active auxins of roots vs. nodules, while levels of the auxin conjugate indole-3-acetic acid-alanine were increased in nodules compared to roots of both species. Because auxins typically act in concert with cytokinins, cytokinins were also quantified. Concentrations of cis-zeatin and some glycosylated cytokinins were dramatically increased in nodules compared to roots of D. glomerata, but not of M. truncatula. The ratio of active auxins to cytokinins remained similar in nodules compared to roots in both species. The auxin response, as shown by the activation of the DR5 promoter, seemed significantly reduced in nodules compared to roots of both species, suggesting the accumulation of auxins in cell types that do not express the signal transduction pathway leading to DR5 activation. Effects on root development were analyzed for the synthetic auxin naphthaleneacetic acid (NAA) and PAA, the dominant auxin in nodules. Both auxins had similar effects, except that the sensitivity of roots to PAA was lower than to NAA. However, while the effects of both auxins on primary root growth were similar for both species, effects on root branching were different: both auxins had the classical positive effect on root branching in M. truncatula, but a negative effect in D. glomerata. Such a negative effect of exogenous auxin on root branching has previously been found for a cucurbit that forms lateral root primordia in the meristem of the parental root; however, root branching in D. glomerata does not follow that pattern.
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Affiliation(s)
- Irina V. Demina
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Pooja Jha Maity
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Anurupa Nagchowdhury
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Jason L. P. Ng
- Division of Plant Science, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Eric van der Graaff
- Department of Plant Physiology, Karl-Franzens-Universität Graz, Graz, Austria
| | - Kirill N. Demchenko
- Laboratory of Cellular and Molecular Mechanisms of Plant Development, Komarov Botanical Institute, Russian Academy of Sciences, Saint-Petersburg, Russia
- Laboratory of Molecular and Cellular Biology, All-Russia Research Institute for Agricultural Microbiology, Saint-Petersburg, Russia
| | - Thomas Roitsch
- Department of Plant Physiology, Karl-Franzens-Universität Graz, Graz, Austria
| | - Ulrike Mathesius
- Division of Plant Science, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Katharina Pawlowski
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- *Correspondence: Katharina Pawlowski,
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