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Rasouli F, Kiani-Pouya A, Movahedi A, Wang Y, Li L, Yu M, Pourkheirandish M, Zhou M, Chen Z, Zhang H, Shabala S. Guard Cell Transcriptome Reveals Membrane Transport, Stomatal Development and Cell Wall Modifications as Key Traits Involved in Salinity Tolerance in Halophytic Chenopodium quinoa. PLANT & CELL PHYSIOLOGY 2023; 64:204-220. [PMID: 36355785 DOI: 10.1093/pcp/pcac158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 11/06/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
A comparative investigation was conducted to evaluate transcriptional changes in guard cells (GCs) of closely related halophytic (Chenopodium quinoa) and glycophytic (Spinacia oleracea) species. Plants were exposed to 3 weeks of 250 mM sodium chloride treatment, and GC-enriched epidermal fragments were mechanically prepared. In both species, salt-responsive genes were mainly related to categories of protein metabolism, secondary metabolites, signal transduction and transport systems. Genes related to abscisic acid (ABA) signaling and ABA biosynthesis were strongly induced in quinoa but not in spinach GCs. Also, expression of the genes encoding transporters of amino acids, proline, sugars, sucrose and potassium increased in quinoa GCs under salinity stress. Analysis of cell-wall-related genes suggests that genes involved in lignin synthesis (e.g. lignin biosynthesis LACCASE 4) were highly upregulated by salt in spinach GCs. In contrast, transcripts related to cell wall plasticity Pectin methylesterase3 (PME3) were highly induced in quinoa. Faster stomatal response to light and dark measured by observing kinetics of changes in stomatal conductance in quinoa might be associated with higher plasticity of the cell wall regulated by PME3 Furthermore, genes involved in the inhibition of stomatal development and differentiation were highly expressed by salt in quinoa, but not in spinach. These changes correlated with reduced stomatal density and index in quinoa, thus improving its water use efficiency. The fine modulation of transporters, cell wall modification and controlling stomatal development in GCs of quinoa may have resulted in high K+/Na+ ratio, lower stomatal conductance and higher stomatal speed for better adaptation to salinity stress in quinoa.
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Affiliation(s)
- Fatemeh Rasouli
- Tasmanian Institute of Agriculture, College of Science and Engineering, University of Tasmania, Hobart, TAS 7001, Australia
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China
- State Key Laboratory of Molecular Plant Genetics, Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Ali Kiani-Pouya
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
- State Key Laboratory of Molecular Plant Genetics, Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Ali Movahedi
- Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Yuan Wang
- State Key Laboratory of Molecular Plant Genetics, Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Leiting Li
- State Key Laboratory of Molecular Plant Genetics, Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Min Yu
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China
| | - Mohammad Pourkheirandish
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Meixue Zhou
- Tasmanian Institute of Agriculture, College of Science and Engineering, University of Tasmania, Hobart, TAS 7001, Australia
| | - Zhonghua Chen
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2747, Australia
| | - Heng Zhang
- State Key Laboratory of Molecular Plant Genetics, Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Sergey Shabala
- Tasmanian Institute of Agriculture, College of Science and Engineering, University of Tasmania, Hobart, TAS 7001, Australia
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China
- School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia
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Tojo H, Tabeta H, Gunji S, Hirai MY, David P, Javot H, Ferjani A. Roles of type II H +-PPases and PPsPase1/PECP2 in early developmental stages and PPi homeostasis of Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2023; 14:1031426. [PMID: 36778688 PMCID: PMC9911876 DOI: 10.3389/fpls.2023.1031426] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
The regulation of intracellular pyrophosphate (PPi) level is crucial for proper morphogenesis across all taxonomic kingdoms. PPi is released as a byproduct from ~200 metabolic reactions, then hydrolyzed by either membrane-bound (H+-PPase) or soluble pyrophosphatases (PPases). In Arabidopsis, the loss of the vacuolar H+-PPase/FUGU5, a key enzyme in PPi homeostasis, results in delayed growth and a number of developmental defects, pointing to the importance of PPi homeostasis in plant morphogenesis. The Arabidopsis genome encodes several PPases in addition to FUGU5, such as PPsPase1/PECP2, VHP2;1 and VHP2;2, although their significance regarding PPi homeostasis remains elusive. Here, to assess their contribution, phenotypic analyses of cotyledon aspect ratio, palisade tissue cellular phenotypes, adaxial side pavement cell complexity, stomatal distribution, and etiolated seedling length were performed, provided that they were altered due to excess PPi in a fugu5 mutant background. Overall, our analyses revealed that the above five traits were unaffected in ppspase1/pecp2, vhp2;1 and vhp2;2 loss-of-function mutants, as well as in fugu5 mutant lines constitutively overexpressing PPsPase1/PECP2. Furthermore, metabolomics revealed that ppspase1/pecp2, vhp2;1 and vhp2;2 etiolated seedlings exhibited metabolic profiles comparable to the wild type. Together, these results indicate that the contribution of PPsPase1/PECP2, VHP2;1 and VHP2;2 to PPi levels is negligible in comparison to FUGU5 in the early stages of seedling development.
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Affiliation(s)
- Hiroshi Tojo
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
| | - Hiromitsu Tabeta
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Shizuka Gunji
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
| | - Masami Y. Hirai
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Pascale David
- Aix Marseille Univ, CEA, CNRS, BIAM, Saint Paul-Lez-Durance, France
| | - Hélène Javot
- Aix Marseille Univ, CEA, CNRS, BIAM, Saint Paul-Lez-Durance, France
- Aix Marseille Univ, CEA, CNRS, BIAM, Marseille, France
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
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Tabeta H, Gunji S, Kawade K, Ferjani A. Leaf-size control beyond transcription factors: Compensatory mechanisms. FRONTIERS IN PLANT SCIENCE 2023; 13:1024945. [PMID: 36756231 PMCID: PMC9901582 DOI: 10.3389/fpls.2022.1024945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/28/2022] [Indexed: 06/18/2023]
Abstract
Plant leaves display abundant morphological richness yet grow to characteristic sizes and shapes. Beginning with a small number of undifferentiated founder cells, leaves evolve via a complex interplay of regulatory factors that ultimately influence cell proliferation and subsequent post-mitotic cell enlargement. During their development, a sequence of key events that shape leaves is both robustly executed spatiotemporally following a genomic molecular network and flexibly tuned by a variety of environmental stimuli. Decades of work on Arabidopsis thaliana have revisited the compensatory phenomena that might reflect a general and primary size-regulatory mechanism in leaves. This review focuses on key molecular and cellular events behind the organ-wide scale regulation of compensatory mechanisms. Lastly, emerging novel mechanisms of metabolic and hormonal regulation are discussed, based on recent advances in the field that have provided insights into, among other phenomena, leaf-size regulation.
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Affiliation(s)
- Hiromitsu Tabeta
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Shizuka Gunji
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Kensuke Kawade
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- National Institute for Basic Biology, Okazaki, Japan
- Department of Basic Biology, School of Life Science, Graduate University for Advanced Studies (SOKENDAI), Okazaki, Japan
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
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Gunji S, Kawade K, Tabeta H, Horiguchi G, Oikawa A, Asaoka M, Hirai MY, Tsukaya H, Ferjani A. Tissue-targeted inorganic pyrophosphate hydrolysis in a fugu5 mutant reveals that excess inorganic pyrophosphate triggers developmental defects in a cell-autonomous manner. FRONTIERS IN PLANT SCIENCE 2022; 13:945225. [PMID: 35991393 PMCID: PMC9386291 DOI: 10.3389/fpls.2022.945225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Excess PPi triggers developmental defects in a cell-autonomous manner. The level of inorganic pyrophosphate (PPi) must be tightly regulated in all kingdoms for the proper execution of cellular functions. In plants, the vacuolar proton pyrophosphatase (H+-PPase) has a pivotal role in PPi homeostasis. We previously demonstrated that the excess cytosolic PPi in the H+-PPase loss-of-function fugu5 mutant inhibits gluconeogenesis from seed storage lipids, arrests cell division in cotyledonary palisade tissue, and triggers a compensated cell enlargement (CCE). Moreover, PPi alters pavement cell (PC) shape, stomatal patterning, and functioning, supporting specific yet broad inhibitory effects of PPi on leaf morphogenesis. Whereas these developmental defects were totally rescued by the expression of the yeast soluble pyrophosphatase IPP1, sucrose supply alone canceled CCE in the palisade tissue but not the epidermal developmental defects. Hence, we postulated that the latter are likely triggered by excess PPi rather than a sucrose deficit. To formally test this hypothesis, we adopted a spatiotemporal approach by constructing and analyzing fugu5-1 PDF1 pro ::IPP1, fugu5-1 CLV1 pro ::IPP1, and fugu5-1 ICL pro ::IPP1, whereby PPi was removed specifically from the epidermis, palisade tissue cells, or during the 4 days following seed imbibition, respectively. It is important to note that whereas PC defects in fugu5-1 PDF1 pro ::IPP1 were completely recovered, those in fugu5-1 CLV1 pro ::IPP1 were not. In addition, phenotypic analyses of fugu5-1 ICL pro ::IPP1 lines demonstrated that the immediate removal of PPi after seed imbibition markedly improved overall plant growth, abolished CCE, but only partially restored the epidermal developmental defects. Next, the impact of spatial and temporal removal of PPi was investigated by capillary electrophoresis time-of-flight mass spectrometry (CE-TOF MS). Our analysis revealed that the metabolic profiles are differentially affected among all the above transgenic lines, and consistent with an axial role of central metabolism of gluconeogenesis in CCE. Taken together, this study provides a conceptual framework to unveil metabolic fluctuations within leaf tissues with high spatio-temporal resolution. Finally, our findings suggest that excess PPi exerts its inhibitory effect in planta in the early stages of seedling establishment in a tissue- and cell-autonomous manner.
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Affiliation(s)
- Shizuka Gunji
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
- United Graduate School of Education, Tokyo Gakugei University, Tokyo, Japan
| | - Kensuke Kawade
- National Institute for Basic Biology, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Sciences, Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Hiromitsu Tabeta
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Gorou Horiguchi
- Department of Life Science, College of Science, Rikkyo University, Tokyo, Japan
- Research Center for Life Science, College of Science, Rikkyo University, Tokyo, Japan
| | - Akira Oikawa
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Faculty of Agriculture, Yamagata University, Tsuruoka, Japan
| | - Mariko Asaoka
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
| | - Masami Yokota Hirai
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Department of Applied Biosciences, Graduate School of Bioagricultural Science, Nagoya University, Nagoya, Japan
| | - Hirokazu Tsukaya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, Koganei, Tokyo, Japan
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Tabeta H, Watanabe S, Fukuda K, Gunji S, Asaoka M, Hirai MY, Seo M, Tsukaya H, Ferjani A. An auxin signaling network translates low-sugar-state input into compensated cell enlargement in the fugu5 cotyledon. PLoS Genet 2021; 17:e1009674. [PMID: 34351899 PMCID: PMC8341479 DOI: 10.1371/journal.pgen.1009674] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/18/2021] [Indexed: 01/29/2023] Open
Abstract
In plants, the effective mobilization of seed nutrient reserves is crucial during germination and for seedling establishment. The Arabidopsis H+-PPase-loss-of-function fugu5 mutants exhibit a reduced number of cells in the cotyledons. This leads to enhanced post-mitotic cell expansion, also known as compensated cell enlargement (CCE). While decreased cell numbers have been ascribed to reduced gluconeogenesis from triacylglycerol, the molecular mechanisms underlying CCE remain ill-known. Given the role of indole 3-butyric acid (IBA) in cotyledon development, and because CCE in fugu5 is specifically and completely cancelled by ech2, which shows defective IBA-to-indoleacetic acid (IAA) conversion, IBA has emerged as a potential regulator of CCE. Here, to further illuminate the regulatory role of IBA in CCE, we used a series of high-order mutants that harbored a specific defect in IBA-to-IAA conversion, IBA efflux, IAA signaling, or vacuolar type H+-ATPase (V-ATPase) activity and analyzed the genetic interaction with fugu5-1. We found that while CCE in fugu5 was promoted by IBA, defects in IBA-to-IAA conversion, IAA response, or the V-ATPase activity alone cancelled CCE. Consistently, endogenous IAA in fugu5 reached a level 2.2-fold higher than the WT in 1-week-old seedlings. Finally, the above findings were validated in icl-2, mls-2, pck1-2 and ibr10 mutants, in which CCE was triggered by low sugar contents. This provides a scenario in which following seed germination, the low-sugar-state triggers IAA synthesis, leading to CCE through the activation of the V-ATPase. These findings illustrate how fine-tuning cell and organ size regulation depend on interplays between metabolism and IAA levels in plants.
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Affiliation(s)
- Hiromitsu Tabeta
- Department of Biology, Tokyo Gakugei University, Koganei-shi, Tokyo, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo, Japan
| | | | - Keita Fukuda
- Department of Biology, Tokyo Gakugei University, Koganei-shi, Tokyo, Japan
| | - Shizuka Gunji
- Department of Biology, Tokyo Gakugei University, Koganei-shi, Tokyo, Japan
| | - Mariko Asaoka
- Department of Biology, Tokyo Gakugei University, Koganei-shi, Tokyo, Japan
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, UCB Lyon 1, ENS de Lyon, INRA, CNRS, Lyon, France
| | | | - Mitsunori Seo
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Hirokazu Tsukaya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, Koganei-shi, Tokyo, Japan
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Rasouli F, Kiani-Pouya A, Zhang H, Shabala S. Developing and validating protocols for mechanical isolation of guard-cell enriched epidermal peels for omics studies. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:803-814. [PMID: 32513383 DOI: 10.1071/fp20085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Stomata, which are microscopic valves on the leaf surface formed by two guard cells (GC), play a critical role in the regulation of leaf water and gas exchange and, hence, determine plant adaptive potential. However, little data is available on GC biochemistry, protein abundance and gene expression, mainly due to technical difficulties and challenges in isolating sufficient amounts of high-quality pure GC. In the present study we applied some modifications to the mechanical isolation of guard-cell to generalise this method for diverse growth conditions as well as plant species. Epidermal peel fragments enriched in guard cells were mechanically isolated from quinoa, spinach and sugar beet leaves grown at two conditions (normal and salt stress). Multiple analysis was performed to confirm the suitability and superiority of the modified technique to the original method. At the first step, the viability and purity of GC-enriched epidermal fragments were assessed under the microscope. Then, the RNA integrity, gene expression, and 1D SDS-PAGE tests were performed to validate the suitability of this technique for omics studies. The data revealed a wide range of proteins as well as a high integrity of RNA extracted from guard cell samples. The expression level of several GC-specific genes and mesophyll-dominant genes were investigated using a comparative analysis of transcriptome datasets of GC and whole-leaf samples. We found that Rubisco and photosynthesis-related proteins such as chlorophyll a/b binding protein were substantially higher in the whole leaf compared with the GCs. More importantly, GC-specific genes such as OST1, SLAC1, MYB60, FAMA and HT1 were highly expressed in the GCs, confirming that our guard cell preparation was highly enriched in GC gene transcripts. Real-time quantitative reverse transcription PCR further confirmed the efficacy of the GC isolation technique for exploring responses of GC to diverse types of stress at the molecular level.
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Affiliation(s)
- Fatemeh Rasouli
- Tasmanian Institute of Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tas. 7001, Australia; and Shanghai Centre for Plant Stress Biology and CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 201602 Shanghai, China
| | - Ali Kiani-Pouya
- Tasmanian Institute of Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tas. 7001, Australia; and Shanghai Centre for Plant Stress Biology and CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 201602 Shanghai, China
| | - Heng Zhang
- Shanghai Centre for Plant Stress Biology and CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 201602 Shanghai, China
| | - Sergey Shabala
- Tasmanian Institute of Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tas. 7001, Australia; and International Research Centre for Environmental Membrane Biology, Foshan University, 528000 Foshan, China; and Corresponding author.
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Fukuda M, Mieda M, Sato R, Kinoshita S, Tomoyama T, Ferjani A, Maeshima M, Segami S. Lack of Vacuolar H + -Pyrophosphatase and Cytosolic Pyrophosphatases Causes Fatal Developmental Defects in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2020; 11:655. [PMID: 32528505 PMCID: PMC7266078 DOI: 10.3389/fpls.2020.00655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
The cytosolic level of inorganic pyrophosphate (PPi) is finely regulated, with PPi hydrolyzed primarily by the vacuolar H+-pyrophosphatase (H+-PPase, VHP1/FUGU5/AVP1) and secondarily by five cytosolic soluble pyrophosphatases (sPPases; PPa1-PPa5) in Arabidopsis thaliana. Loss-of-function mutants of H+-PPase (fugu5s) have been reported to show atrophic phenotypes in their rosette leaves when nitrate is the sole nitrogen source in the culture medium. For this phenotype, two questions remain unanswered: why does atrophy depend on physical contact between shoots and the medium, and how does ammonium prevent such atrophy. To understand the mechanism driving this phenotype, we analyzed the growth and phenotypes of mutants on ammonium-free medium in detail. fugu5-1 showed cuticle defects, cell swelling, reduced β-glucan levels, and vein malformation in the leaves, suggesting cell wall weakening and cell lethality. Based on the observation in the double mutants fugu5-1 ppa1 and fugu5-1 ppa4 of more severe atrophy compared to fugu5-1, the nitrogen-dependent phenotype might be linked to PPi metabolism. To elucidate the role of ammonium in this process, we examined the fluctuations of sPPase mRNA levels and the possibility of alternative PPi-removing factors, such as other types of pyrophosphatase. First, we found that both the protein and mRNA levels of sPPases were unaffected by the nitrogen source. Second, to assess the influence of other PPi-removing factors, we examined the phenotypes of triple knockout mutants of H+-PPase and two sPPases on ammonium-containing medium. Both fugu5 ppa1 ppa2 and fugu5 ppa1 ppa4 had nearly lethal embryonic phenotypes, with the survivors showing striking dwarfism and abnormal morphology. Moreover, fugu5 ppa1+/- ppa4 showed severe atrophy at the leaf margins. The other triple mutants, fugu5 ppa1 ppa5 and fugu5 ppa2 ppa4, exhibited death of root hairs and were nearly sterile due to deformed pistils, respectively, even when grown on standard medium. Together, these results suggest that H+-PPase and sPPases act in concert to maintain PPi homeostasis, that the existence of other PPi removers is unlikely, and that ammonium may suppress the production of PPi during nitrogen metabolism rather than stimulating PPi hydrolysis.
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Affiliation(s)
- Mayu Fukuda
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Marika Mieda
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Ryosuke Sato
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Satoru Kinoshita
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Takaaki Tomoyama
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Masayoshi Maeshima
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- Graduate School of Bioscience and Biotechnology, Chubu University, Kasugai, Japan
| | - Shoji Segami
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- National Institute for Basic Biology, Okazaki, Japan
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Sugar Beet ( Beta vulgaris) Guard Cells Responses to Salinity Stress: A Proteomic Analysis. Int J Mol Sci 2020; 21:ijms21072331. [PMID: 32230932 PMCID: PMC7212754 DOI: 10.3390/ijms21072331] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 02/02/2023] Open
Abstract
Soil salinity is a major environmental constraint affecting crop growth and threatening global food security. Plants adapt to salinity by optimizing the performance of stomata. Stomata are formed by two guard cells (GCs) that are morphologically and functionally distinct from the other leaf cells. These microscopic sphincters inserted into the wax-covered epidermis of the shoot balance CO2 intake for photosynthetic carbon gain and concomitant water loss. In order to better understand the molecular mechanisms underlying stomatal function under saline conditions, we used proteomics approach to study isolated GCs from the salt-tolerant sugar beet species. Of the 2088 proteins identified in sugar beet GCs, 82 were differentially regulated by salt treatment. According to bioinformatics analysis (GO enrichment analysis and protein classification), these proteins were involved in lipid metabolism, cell wall modification, ATP biosynthesis, and signaling. Among the significant differentially abundant proteins, several proteins classified as "stress proteins" were upregulated, including non-specific lipid transfer protein, chaperone proteins, heat shock proteins, inorganic pyrophosphatase 2, responsible for energized vacuole membrane for ion transportation. Moreover, several antioxidant enzymes (peroxide, superoxidase dismutase) were highly upregulated. Furthermore, cell wall proteins detected in GCs provided some evidence that GC walls were more flexible in response to salt stress. Proteins such as L-ascorbate oxidase that were constitutively high under both control and high salinity conditions may contribute to the ability of sugar beet GCs to adapt to salinity by mitigating salinity-induced oxidative stress.
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Gunji S, Oda Y, Takigawa-Imamura H, Tsukaya H, Ferjani A. Excess Pyrophosphate Restrains Pavement Cell Morphogenesis and Alters Organ Flatness in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2020; 11:31. [PMID: 32153602 PMCID: PMC7047283 DOI: 10.3389/fpls.2020.00031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/13/2020] [Indexed: 05/31/2023]
Abstract
In Arabidopsis thaliana, the vacuolar proton-pumping pyrophosphatase (H+-PPase) is highly expressed in young tissues, which consume large amounts of energy in the form of nucleoside triphosphates and produce pyrophosphate (PPi) as a byproduct. We reported that excess PPi in the H+-PPase loss-of-function fugu5 mutant severely compromised gluconeogenesis from seed storage lipids, arrested cell division in cotyledonary palisade tissue, and triggered compensated cell enlargement; this phenotype was recovered upon sucrose supply. Thus, we provided evidence that the hydrolysis of inhibitory PPi, rather than vacuolar acidification, is the major contribution of H+-PPase during seedling establishment. Here, examination of the epidermis revealed that fugu5 pavement cells exhibited defective puzzle-cell formation. Importantly, removal of PPi from fugu5 background by the yeast cytosolic PPase IPP1, in fugu5-1 AVP1pro::IPP1 transgenic lines, restored the phenotypic aberrations of fugu5 pavement cells. Surprisingly, pavement cells in mutants with defects in gluconeogenesis (pck1-2) or the glyoxylate cycle (icl-2; mls-2) showed no phenotypic alteration, indicating that reduced sucrose production from seed storage lipids is not the cause of fugu5 epidermal phenotype. fugu5 had oblong cotyledons similar to those of angustifolia-1 (an-1), whose leaf pavement cells display an abnormal arrangement of cortical microtubules (MTs). To gain insight into the genetic interaction between ANGUSTIFOLIA and H+-PPase in pavement cell differentiation, an-1 fugu5-1 was analyzed. Surprisingly, epidermis developmental defects were synergistically enhanced in the double mutant. In fact, an-1 fugu5-1 pavement cells showed a striking three-dimensional growth phenotype on both abaxial and adaxial sides of cotyledons, which was recovered by hydrolysis of PPi in an-1 fugu5-1 AVP1pro::IPP1. Live imaging revealed that cortical MTs exhibited a reduced velocity, were slightly fragmented and sparse in the above lines compared to the WT. Consistently, addition of PPi in vitro led to a dose-dependent delay of tubulin polymerization, thus supporting a link between PPi and MT dynamics. Moreover, mathematical simulation of three-dimensional growth based on cotyledon proximo-distal and medio-lateral phenotypic quantification implicated restricted cotyledon expansion along the medio-lateral axis in the crinkled surface of an-1 fugu5-1. Together, our data suggest that PPi homeostasis is a prerequisite for proper pavement cell morphogenesis, epidermal growth and development, and organ flattening.
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Affiliation(s)
- Shizuka Gunji
- United Graduate School of Education, Tokyo Gakugei University, Tokyo, Japan
| | - Yoshihisa Oda
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan
- Department of Genetics, The Graduate University for Advanced Studies, SOKENDAI, Mishima, Japan
| | - Hisako Takigawa-Imamura
- Department of Anatomy and Cell Biology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hirokazu Tsukaya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ali Ferjani
- United Graduate School of Education, Tokyo Gakugei University, Tokyo, Japan
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
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