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Tanimoto H, Umekawa Y, Takahashi H, Goto K, Ito K. Gene expression and metabolite levels converge in the thermogenic spadix of skunk cabbage. PLANT PHYSIOLOGY 2024; 195:1561-1585. [PMID: 38318875 PMCID: PMC11142342 DOI: 10.1093/plphys/kiae059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 02/07/2024]
Abstract
The inflorescence (spadix) of skunk cabbage (Symplocarpus renifolius) is strongly thermogenic and can regulate its temperature at around 23 °C even when the ambient temperature drops below freezing. To elucidate the mechanisms underlying developmentally controlled thermogenesis and thermoregulation in skunk cabbage, we conducted a comprehensive transcriptome and metabolome analysis across 3 developmental stages of spadix development. Our RNA-seq analysis revealed distinct groups of expressed genes, with selenium-binding protein 1/methanethiol oxidase (SBP1/MTO) exhibiting the highest levels in thermogenic florets. Notably, the expression of alternative oxidase (AOX) was consistently high from the prethermogenic stage through the thermogenic stage in the florets. Metabolome analysis showed that alterations in nucleotide levels correspond with the developmentally controlled and tissue-specific thermogenesis of skunk cabbage, evident by a substantial increase in AMP levels in thermogenic florets. Our study also reveals that hydrogen sulfide, a product of SBP1/MTO, inhibits cytochrome c oxidase (COX)-mediated mitochondrial respiration, while AOX-mediated respiration remains relatively unaffected. Specifically, at lower temperatures, the inhibitory effect of hydrogen sulfide on COX-mediated respiration increases, promoting a shift toward the dominance of AOX-mediated respiration. Finally, despite the differential regulation of genes and metabolites throughout spadix development, we observed a convergence of gene expression and metabolite accumulation patterns during thermogenesis. This synchrony may play a key role in developmentally regulated thermogenesis. Moreover, such convergence during the thermogenic stage in the spadix may provide a solid molecular basis for thermoregulation in skunk cabbage.
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Affiliation(s)
- Haruka Tanimoto
- United Graduate School of Agricultural Science, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Yui Umekawa
- Department of Planning and General Affairs, Akita Research Institute of Food and Brewing, Araya-machi, Akita 010-1623, Japan
| | - Hideyuki Takahashi
- Department of Agriculture, School of Agriculture, Tokai University, Kumamoto 862-8652, Japan
| | - Kota Goto
- Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Kikukatsu Ito
- United Graduate School of Agricultural Science, Iwate University, Morioka, Iwate 020-8550, Japan
- Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
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2
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Koyamatsu D, Otsubo M, Ohira T, Sato MP, Suzuki-Masuko H, Shiota T, Takenaka Takano K, Ozeki M, Otsuka K, Ogura Y, Hayashi T, Watanabe M, Inaba T, Ito-Inaba Y. Molecular characterization of SrSTP14, a sugar transporter from thermogenic skunk cabbage, and its possible role in developing pollen. PHYSIOLOGIA PLANTARUM 2023; 175:e13957. [PMID: 37338180 DOI: 10.1111/ppl.13957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/13/2023] [Accepted: 06/15/2023] [Indexed: 06/21/2023]
Abstract
In floral thermogenesis, sugars play an important role not only as energy providers but also as growth and development facilitators. Yet, the mechanisms underlying sugar translocation and transport in thermogenic plants remain to be studied. Asian skunk cabbage (Symplocarpus renifolius) is a species that can produce durable and intense heat in its reproductive organ, the spadix. Significant morphological and developmental changes in the stamen are well-characterized in this plant. In this study, we focused on the sugar transporters (STPs), SrSTP1 and SrSTP14, whose genes were identified by RNA-seq as the upregulated STPs during thermogenesis. Real-time PCR confirmed that mRNA expression of both STP genes was increased from the pre-thermogenic to the thermogenic stage in the spadix, where it is predominantly expressed in the stamen. SrSTP1 and SrSTP14 complemented the growth defects of a hexose transporter-deficient yeast strain, EBY4000, on media containing 0.02, 0.2, and 2% (w/v) glucose and galactose. Using a recently developed transient expression system in skunk cabbage leaf protoplasts, we revealed that SrSTP1 and SrSTP14-GFP fusion proteins were mainly localized to the plasma membrane. To dig further into the functional analysis of SrSTPs, tissue-specific localization of SrSTPs was investigated by in situ hybridization. Using probes for SrSTP14, mRNA expression was observed in the microspores within the developing anther at the thermogenic female stage. These results indicate that SrSTP1 and SrSTP14 transport hexoses (e.g., glucose and galactose) at the plasma membrane and suggest that SrSTP14 may play a role in pollen development through the uptake of hexoses into pollen precursor cells.
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Affiliation(s)
- Daiki Koyamatsu
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Miyabi Otsubo
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Tomonori Ohira
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Mitsuhiko P Sato
- Department of Frontier Research and Development, Kazusa DNA Research Institute, Kisarazu, Japan
| | | | - Takuya Shiota
- Organization for Promotion of Tenure Track, University of Miyazaki, Miyazaki, Japan
- Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Kohei Takenaka Takano
- Natural Environment Division, Nagano Environmental Conservation Research Institute, Nagano, Japan
| | - Masaaki Ozeki
- Natural Environment Division, Nagano Environmental Conservation Research Institute, Nagano, Japan
| | - Koichi Otsuka
- Natural Environment Division, Nagano Environmental Conservation Research Institute, Nagano, Japan
| | - Yoshitoshi Ogura
- Division of Microbiology, Department of Infectious Medicine, Kurume University School of Medicine, Fukuoka, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masao Watanabe
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Takehito Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Yasuko Ito-Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
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3
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Sato MP, Matsuo A, Otsuka K, Takano KT, Maki M, Okano K, Suyama Y, Ito‐Inaba Y. Potential contribution of floral thermogenesis to cold adaptation, distribution pattern, and population structure of thermogenic and non/slightly thermogenic Symplocarpus species. Ecol Evol 2023; 13:e10319. [PMID: 37456070 PMCID: PMC10349278 DOI: 10.1002/ece3.10319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 06/28/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023] Open
Abstract
The genus Symplocarpus in basal Araceae includes both thermogenic and non/slightly thermogenic species that prefer cold environments. If floral thermogenesis of Symplocarpus contributes to cold adaptation, it would be expected that thermogenic species have a larger habitat than non/slightly thermogenic species during an ice age, leading to increased genetic diversity in the current population. To address this question, potential distribution in past environment predicted by ecological niche modeling (ENM), genetic diversity, and population structure of chloroplast and genome-wide single nucleotide polymorphisms were compared between thermogenic Symplocarpus renifolius and non/slightly thermogenic Symplocarpus nipponicus. ENM revealed that the distribution of S. nipponicus decreased, whereas that of S. renifolius expanded in the Last Glacial Maximum. Phylogeographic analyses have shown that the population structures of the two species were genetically segmented and that the genetic diversity of S. renifolius was higher than that of S. nipponicus. The phylogenetic relationship between chloroplast and nuclear DNA is topologically different in the two species, which may be due to the asymmetric gene flow ubiquitously observed in plants. The results of this study imply that floral thermogenesis of Symplocarpus contributes to expanding the distribution during an ice age, resulting in increased genetic diversity due to cold adaptation.
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Affiliation(s)
| | - Ayumi Matsuo
- Kawatabi Field Science Center, Graduate School of Agricultural ScienceTohoku UniversityOsakiJapan
| | - Koichi Otsuka
- Tomono‐Kai Society of Nagano Environmental Conservation Research InstituteNaganoJapan
| | - Kohei Takenaka Takano
- Natural Environment DivisionNagano Environmental Conservation Research InstituteNaganoJapan
| | - Masayuki Maki
- Botanical GardensTohoku UniversitySendaiJapan
- Graduate School of Life SciencesTohoku UniversitySendaiJapan
| | - Kunihiro Okano
- Department of Biological EnvironmentAkita Prefectural UniversityAkitaJapan
| | - Yoshihisa Suyama
- Kawatabi Field Science Center, Graduate School of Agricultural ScienceTohoku UniversityOsakiJapan
| | - Yasuko Ito‐Inaba
- Graduate School of Life SciencesTohoku UniversitySendaiJapan
- Department of Agricultural and Environmental Sciences, Faculty of AgricultureUniversity of MiyazakiMiyazakiJapan
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Okabe K, Uchiyama S. Intracellular thermometry uncovers spontaneous thermogenesis and associated thermal signaling. Commun Biol 2021; 4:1377. [PMID: 34887517 PMCID: PMC8660847 DOI: 10.1038/s42003-021-02908-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/17/2021] [Indexed: 02/06/2023] Open
Abstract
Conventional thermal biology has elucidated the physiological function of temperature homeostasis through spontaneous thermogenesis and responses to variations in environmental temperature in organisms. In addition to research on individual physiological phenomena, the molecular mechanisms of fever and physiological events such as temperature-dependent sex determination have been intensively addressed. Thermosensitive biomacromolecules such as heat shock proteins (HSPs) and transient receptor potential (TRP) channels were systematically identified, and their sophisticated functions were clarified. Complementarily, recent progress in intracellular thermometry has opened new research fields in thermal biology. High-resolution intracellular temperature mapping has uncovered thermogenic organelles, and the thermogenic functions of brown adipocytes were ascertained by the combination of intracellular thermometry and classic molecular biology. In addition, intracellular thermometry has introduced a new concept, "thermal signaling", in which temperature variation within biological cells acts as a signal in a cascade of intriguing biological events.
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Affiliation(s)
- Kohki Okabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
- JST, PRESTO, Saitama, Japan.
| | - Seiichi Uchiyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
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Barreto P, Couñago RM, Arruda P. Mitochondrial uncoupling protein-dependent signaling in plant bioenergetics and stress response. Mitochondrion 2020; 53:109-120. [DOI: 10.1016/j.mito.2020.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/06/2020] [Accepted: 05/14/2020] [Indexed: 12/15/2022]
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6
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Ito-Inaba Y, Sato M, Sato MP, Kurayama Y, Yamamoto H, Ohata M, Ogura Y, Hayashi T, Toyooka K, Inaba T. Alternative Oxidase Capacity of Mitochondria in Microsporophylls May Function in Cycad Thermogenesis. PLANT PHYSIOLOGY 2019; 180:743-756. [PMID: 30918084 PMCID: PMC6548267 DOI: 10.1104/pp.19.00150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 03/12/2019] [Indexed: 06/09/2023]
Abstract
Cone thermogenesis is a widespread phenomenon in cycads and may function to promote volatile emissions that affect pollinator behavior. Given their large population size and intense and durable heat-producing effects, cycads are important organisms for comprehensive studies of plant thermogenesis. However, knowledge of mitochondrial morphology and function in cone thermogenesis is limited. Therefore, we investigated these mitochondrial properties in the thermogenic cycad species Cycas revoluta Male cones generated heat even in cool weather conditions. Female cones produced heat, but to a lesser extent than male cones. Ultrastructural analyses of the two major tissues of male cones, microsporophylls and microsporangia, revealed the existence of a population of mitochondria with a distinct morphology in the microsporophylls. In these cells, we observed large mitochondria (cross-sectional area of 2 μm2 or more) with a uniform matrix density that occupied >10% of the total mitochondrial volume. Despite the size difference, many nonlarge mitochondria (cross-sectional area <2 μm2) also exhibited a shape and a matrix density similar to those of large mitochondria. Alternative oxidase (AOX) capacity and expression levels in microsporophylls were much higher than those in microsporangia. The AOX genes expressed in male cones revealed two different AOX complementary DNA sequences: CrAOX1 and CrAOX2 The expression level of CrAOX1 mRNA in the microsporophylls was 100 times greater than that of CrAOX2 mRNA. Collectively, these results suggest that distinctive mitochondrial morphology and CrAOX1-mediated respiration in microsporophylls might play a role in cycad cone thermogenesis.
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Affiliation(s)
- Yasuko Ito-Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
| | - Mayuko Sato
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Mitsuhiko P Sato
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yuya Kurayama
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
| | - Haruna Yamamoto
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
| | - Mizuki Ohata
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
| | - Yoshitoshi Ogura
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Kiminori Toyooka
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Takehito Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
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7
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Cold Treatment Induces Transient Mitochondrial Fragmentation in Arabidopsis thaliana in a Way that Requires DRP3A but not ELM1 or an ELM1-Like Homologue, ELM2. Int J Mol Sci 2017; 18:ijms18102161. [PMID: 29039787 PMCID: PMC5666842 DOI: 10.3390/ijms18102161] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/09/2017] [Accepted: 10/13/2017] [Indexed: 11/17/2022] Open
Abstract
The number, size and shape of polymorphic plant mitochondria are determined at least partially by mitochondrial fission. Arabidopsis mitochondria divide through the actions of a dynamin-related protein, DRP3A. Another plant-specific factor, ELM1, was previously shown to localize DRP3A to mitochondrial fission sites. Here, we report that mitochondrial fission is not completely blocked in the Arabidopsis elm1 mutant and that it is strongly manifested in response to cold treatment. Arabidopsis has an ELM1 paralogue (ELM2) that seems to have only a limited role in mitochondrial fission in the elm1 mutant. Interestingly, cold-induced mitochondrial fragmentation was also observed in the wild-type, but not in a drp3a mutant, suggesting that cold-induced transient mitochondrial fragmentation requires DRP3A but not ELM1 or ELM2. DRP3A: GFP localized from the cytosol to mitochondrial fission sites without ELM1 after cold treatment. Together, these results suggest that Arabidopsis has a novel, cold-induced type of mitochondrial fission in which DRP3A localizes to mitochondrial fission sites without the involvement of ELM1 or ELM2.
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Nakano M, Nagai T. Thermometers for monitoring cellular temperature. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2017. [DOI: 10.1016/j.jphotochemrev.2016.12.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Ito-Inaba Y, Masuko-Suzuki H, Maekawa H, Watanabe M, Inaba T. Characterization of two PEBP genes, SrFT and SrMFT, in thermogenic skunk cabbage (Symplocarpus renifolius). Sci Rep 2016; 6:29440. [PMID: 27389636 PMCID: PMC4937424 DOI: 10.1038/srep29440] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/20/2016] [Indexed: 01/17/2023] Open
Abstract
Floral thermogenesis has been found in dozens of primitive seed plants and the reproductive organs in these plants produce heat during anthesis. Thus, characterization of the molecular mechanisms underlying flowering is required to fully understand the role of thermogenesis, but this aspect of thermogenic plant development is largely unknown. In this study, extensive database searches and cloning experiments suggest that thermogenic skunk cabbage (Symplocarpus renifolius), which is a member of the family Araceae, possesses two genes encoding phosphatidyl ethanolamine-binding proteins (PEBP), FLOWERING LOCUS T (SrFT) and MOTHER OF FT AND TFL1 (SrMFT). Functional analyses of SrFT and SrMFT in Arabidopsis indicate that SrFT promotes flowering, whereas SrMFT does not. In S. renifolius, the stage- and tissue-specific expression of SrFT was more evident than that of SrMFT. SrFT was highly expressed in flowers and leaves and was mainly localized in fibrovascular tissues. In addition, microarray analysis revealed that, within floral tissues, SrFT was co-regulated with the genes associated with cellular respiration and mitochondrial function, including ALTERNATIVE OXIDASE gene proposed to play a major role in floral thermogenesis. Taken together, these data suggest that, among the PEBP genes, SrFT plays a role in flowering and floral development in the thermogenic skunk cabbage.
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Affiliation(s)
- Yasuko Ito-Inaba
- Organization for Promotion of Tenure Track, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
| | - Hiromi Masuko-Suzuki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Haruhiko Maekawa
- Organization for Promotion of Tenure Track, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan.,Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
| | - Masao Watanabe
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Takehito Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
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10
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Thermogenesis in plants. UKRAINIAN BOTANICAL JOURNAL 2014. [DOI: 10.15407/ukrbotj71.01.096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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11
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Isolation and gene expression analysis of a papain-type cysteine protease in thermogenic skunk cabbage (Symplocarpus renifolius). Biosci Biotechnol Biochem 2012; 76:1990-2. [PMID: 23047088 DOI: 10.1271/bbb.120434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Skunk cabbage (Symplocarpus renifolius) spadices contain abundant transcripts for cysteine protease (CP). From thermogenic spadices, we isolated SrCPA, a highly expressed CP gene that encoded a papain-type CP. SrCPA is structurally similar to other plant CPs, including the senescence-associated CPs found in aroids. The expression of SrCPA increased during floral development, and was observed in all floral tissues except for the stamens.
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12
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Ito-Inaba Y, Hida Y, Matsumura H, Masuko H, Yazu F, Terauchi R, Watanabe M, Inaba T. The gene expression landscape of thermogenic skunk cabbage suggests critical roles for mitochondrial and vacuolar metabolic pathways in the regulation of thermogenesis. PLANT, CELL & ENVIRONMENT 2012; 35:554-566. [PMID: 21955303 DOI: 10.1111/j.1365-3040.2011.02435.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Floral thermogenesis has been described in several plant species. Because of the lack of comprehensive gene expression profiles in thermogenic plants, the molecular mechanisms by which floral thermogenesis is regulated remain to be established. We examined the gene expression landscape of skunk cabbage (Symplocarpus renifolius) during thermogenic and post-thermogenic stages and identified expressed sequence tags from different developmental stages of the inflorescences using super serial analysis of gene expression (SuperSAGE). In-depth analysis suggested that cellular respiration and mitochondrial functions are significantly enhanced during the thermogenic stage. In contrast, genes involved in stress responses and protein degradation were significantly up-regulated during post-thermogenic stages. Quantitative comparisons indicated that the expression levels of genes involved in cellular respiration were higher in thermogenic spadices than in Arabidopsis inflorescences. Thermogenesis-associated genes seemed to be expressed abundantly in the peripheral tissues of the spadix. Our results suggest that cellular respiration and mitochondrial metabolism play key roles in heat production during floral thermogenesis. On the other hand, vacuolar cysteine protease and other degradative enzymes seem to accelerate senescence and terminate thermogenesis in the post-thermogenic stage.
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Affiliation(s)
- Yasuko Ito-Inaba
- Interdisciplinary Research Organization, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki, Japan.
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13
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Figueira TRS, Arruda P. Differential expression of uncoupling mitochondrial protein and alternative oxidase in the plant response to stress. J Bioenerg Biomembr 2011; 43:67-70. [PMID: 21253844 DOI: 10.1007/s10863-011-9333-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Different cell types, organs and tissues shape their mitochondrial proteome according to the cellular environment that is dictated by differentiation, development and metabolic status. Under each circumstance, members of multigenic families that encode mitochondrial proteins are differentially expressed to meet the mitochondrial metabolic demand. However, the mitochondrial proteome may drastically change in response to stress conditions. Examples of the changes in mitochondrial protein expression caused by stress are represented by the energy-dissipating mitochondrial uncoupling protein (UCP) and alternative oxidase (AOx). UCP and AOx belong to multigenic families in plants, and their members, which are expressed in a time/tissue specific manner, respond differentially to stress conditions. In general, UCP and AOx are not expressed at the same levels concurrently in the same tissue, and the level of each protein varies in each stress condition. In addition, under non-stress conditions, UCP is expressed at much higher levels compared with AOx. The role of their differential expression in plant growth, development and response to stress is discussed.
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Affiliation(s)
- Thais Resende Silva Figueira
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
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Zhu Y, Lu J, Wang J, Chen F, Leng F, Li H. Regulation of thermogenesis in plants: the interaction of alternative oxidase and plant uncoupling mitochondrial protein. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2011; 53:7-13. [PMID: 21205176 DOI: 10.1111/j.1744-7909.2010.01004.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Thermogenesis is a process of heat production in living organisms. It is rare in plants, but it does occur in some species of angiosperm. The heat is generated via plant mitochondrial respiration. As possible involvement in thermogenesis of mitochondrial factors, alternative oxidases (AOXs) and plant uncoupling mitochondrial proteins (PUMPs) have been well studied. AOXs and PUMPs are ubiquitously present in the inner membrane of plant mitochondria. They serve as two major energy dissipation systems that balance mitochondrial respiration and uncoupled phosphorylation by dissipating the H+ redox energy and proton electrochemical gradient (ΔμH+) as heat, respectively. AOXs and PUMPs exert similar physiological functions during homeothermic heat production in thermogenic plants. AOXs have five isoforms, while PUMPs have six. Both AOXs and PUMPs are encoded by small nuclear multigene families. Multiple isoforms are expressed in different tissues or organs. Extensive studies have been done in the area of thermogenesis in higher plants. In this review, we focus on the involvement and regulation of AOXs and PUMPs in thermogenesis.
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Affiliation(s)
- Yan Zhu
- MOE Key Laboratory of Arid and Grassland Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
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15
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Ito-Inaba Y, Hida Y, Inaba T. What is critical for plant thermogenesis? Differences in mitochondrial activity and protein expression between thermogenic and non-thermogenic skunk cabbages. PLANTA 2009; 231:121-130. [PMID: 19859730 DOI: 10.1007/s00425-009-1034-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 10/06/2009] [Indexed: 05/28/2023]
Abstract
Thermogenesis during the blooming of inflorescence is found in several but not all aroids. To understand what is critical for thermogenesis, we investigated the difference between thermogenic and non-thermogenic skunk cabbages (Symplocarpus renifolius and Lysichiton camtschatcensis), which are closely related in morphology and phylogeny. Critical parameters of mitochondrial biogenesis, including density, respiratory activity, and protein expression were compared between these two species. Mitochondrial density, respiratory activity, and the amount of alternative oxidase (AOX) in L. camtschatcensis spadix mitochondria were lower than in S. renifolius spadix mitochondria, while the level of uncoupling protein (UCP) was higher. AOX and UCP mRNAs in L. camtschatcensis were constitutively expressed in various tissues, such as the spadix, the spathe, the stalk, and the leaves. cDNA encoding two putative thermogenic proteins, AOX and UCP were isolated from L. camtschatcensis, and their primary structure was analyzed by multiple alignment and phylogenetic tree reconstruction. AOX and UCP protein of two the skunk cabbage species are closely related in structure, compared with other isoforms in thermogenic plants. Our results suggest that mitochondrial density, respiratory activity, and protein expression, rather than the primary structure of AOX or UCP proteins, may play critical roles in thermogenesis in plants.
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Affiliation(s)
- Yasuko Ito-Inaba
- Cryobiofrontier Research Center, Iwate University, Morioka, 020-8550, Japan.
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