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Liu Q, Zhou Y, Flores Castellanos J, Fettke J. The maltose-related starch degradation pathway promotes the formation of large and spherical transitory starch granules. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 39254098 DOI: 10.1111/tpj.17016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/17/2024] [Accepted: 08/19/2024] [Indexed: 09/11/2024]
Abstract
Previously, in Arabidopsis thaliana, we found atypical spherical starch granules in dpe2ss4 and dpe2phs1ss4. However, the mechanism of such abnormal morphogenesis is still obscure. By tracking starch granule length and thickness with leaf ageing, we reported that the starch granules in dpe2phs1ss4 gradually change to a spherical shape over time. In comparison, Col-0 and the parental line ss4 did not exhibit macroscopic morphological alteration. In this study, firstly, we specify that the additional lack of DPE2 resulted in the gradual alteration of starch granule morphology over time. Similar gradual morphological alterations were also found in dpe2, mex1, and sex4 but not in the other starch degradation-related mutants, such as sex1-8, pwd, and bam3. The gradual alteration of starch morphology can be eliminated by omitting the dark phase, suggesting that the particular impaired starch degradation in dpe2- and mex1-related mutants influences starch morphology. Secondly, we observed that spherical starch morphology generation was accompanied by prominent elevated short glucan chains of amylopectin and an increased amylose proportion. Thirdly, the interplay between soluble starch synthase 2 and branching enzymes was affected and resulted in the formation of spherical starch granules. The resulting spherical starch granules allow for elevated starch synthesis efficiency. Fourthly, the starch phosphate content at the granule surface correlated with the morphology alteration of the starch granules. Herewith, we propose a model that spherical starch granules, accumulated in mutants with a misbalance of the starch degradation pathway, are result of elevated starch synthesis to cope with overloaded carbohydrates.
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Affiliation(s)
- Qingting Liu
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, 14476, Potsdam-Golm, Germany
| | - Yuan Zhou
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476, Potsdam, Germany
| | - Junio Flores Castellanos
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, 14476, Potsdam-Golm, Germany
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, 14476, Potsdam-Golm, Germany
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2
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Otegui MS, Steelheart C, Ma W, Ma J, Kang BH, De Medina Hernandez VS, Dagdas Y, Gao C, Goto-Yamada S, Oikawa K, Nishimura M. Vacuolar degradation of plant organelles. THE PLANT CELL 2024; 36:3036-3056. [PMID: 38657116 PMCID: PMC11371181 DOI: 10.1093/plcell/koae128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/26/2024]
Abstract
Plants continuously remodel and degrade their organelles due to damage from their metabolic activities and environmental stressors, as well as an integral part of their cell differentiation programs. Whereas certain organelles use local hydrolytic enzymes for limited remodeling, most of the pathways that control the partial or complete dismantling of organelles rely on vacuolar degradation. Specifically, selective autophagic pathways play a crucial role in recognizing and sorting plant organelle cargo for vacuolar clearance, especially under cellular stress conditions induced by factors like heat, drought, and damaging light. In these short reviews, we discuss the mechanisms that control the vacuolar degradation of chloroplasts, mitochondria, endoplasmic reticulum, Golgi, and peroxisomes, with an emphasis on autophagy, recently discovered selective autophagy receptors for plant organelles, and crosstalk with other catabolic pathways.
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Affiliation(s)
- Marisa S Otegui
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Charlotte Steelheart
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Wenlong Ma
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Juncai Ma
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Byung-Ho Kang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | | | - Yasin Dagdas
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna 1030, Austria
| | - Caiji Gao
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Shino Goto-Yamada
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow 30-348, Poland
| | - Kazusato Oikawa
- Division of Symbiotic Systems, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Mikio Nishimura
- Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
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3
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Shah FA, Chen Z, Ni F, Kamal KA, Zhang J, Chen J, Ren J. ArNAC148 induces Acer rubrum leaf senescence by activating the transcription of the ABA receptor gene ArPYR13. Int J Biol Macromol 2024; 279:134950. [PMID: 39226982 DOI: 10.1016/j.ijbiomac.2024.134950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 08/20/2024] [Accepted: 08/20/2024] [Indexed: 09/05/2024]
Abstract
Acer rubrum, an ornamental tree known for its stunning autumn colors, has an elusive molecular mechanism that governs its leaf senescence. We performed the genome-wide analysis of NAC transcription factor genes and PYRABACTIN RESISTANCE1-LIKE (PYLs) and found that ArNAC148 and ArPYL13 were significantly upregulated in senescing leaves as compared to mature leaves. Subcellular localization studies confirmed the nuclear localization of ArNAC148 and the cytoplasmic localization of ArPYL13. Electrophoretic mobility shift assay and yeast one-hybrid assay demonstrated that ArNAC148 directly binds to the promoter of ArPYL13. Luciferase reporter assays further showed that ArNAC148 activates the transcription of ArPYL13. The transient expression of ArNAC148 and ArPYL13 in tobacco leaves promoted chlorophyll degradation, increased H2O2 level, MDA contents, and electrolyte leakage in response to abscisic acid (ABA). Moreover, the virus-induced gene silencing of ArNAC148 and ArPYL13 in A. rubrum produced results that were opposite to those observed in transient expression experiments. Our findings suggest that ArNAC148 induces leaf senescence by directly activating the transcription of ArPYL13, providing insights into the ABA-mediated regulatory mechanisms governing leaf senescence in A. rubrum. This study offers new perspectives for researchers to explore the roles of NAC and PYL genes in regulating leaf senescence in woody ornamental plants.
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Affiliation(s)
- Faheem Afzal Shah
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Zhu Chen
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Fang Ni
- Anhui Wenda University of Information Engineering, Anhui Province, Anhui 230032, China
| | - Khan Arif Kamal
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Jimei Zhang
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Jinhuan Chen
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Jie Ren
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
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4
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Völkner C, Holzner LJ, Bünger K, Szulc B, Lewis CM, Klingl A, Kunz HH. Evidence for partial functional overlap of KEA and MSL transport proteins in the chloroplast inner envelope of Arabidopsis thaliana. FEBS Lett 2024; 598:1877-1887. [PMID: 38658177 DOI: 10.1002/1873-3468.14887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/21/2024] [Accepted: 03/23/2024] [Indexed: 04/26/2024]
Abstract
Arabidopsis thaliana possesses two different ion-export mechanisms in the plastid inner envelope membrane. Due to a genome duplication, the transport proteins are encoded by partly redundant loci: K+-efflux antiporter1 (KEA1) and KEA2 and mechanosensitive channel of small conductance-like2 (MSL2) and MSL3. Thus far, a functional link between these two mechanisms has not been established. Here, we show that kea1msl2 loss-of-function mutants exhibit phenotypes such as slow growth, reduced photosynthesis and changes in chloroplast morphology, several of which are distinct from either single mutants and do not resemble kea1kea2 or msl2msl3 double mutants. Our data suggest that KEA1 and MSL2 function in concert to maintain plastid ion homeostasis and osmoregulation. Their interplay is critical for proper chloroplast development, organelle function, and plant performance.
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Affiliation(s)
- Carsten Völkner
- Plant Biochemistry, LMU Munich, Planegg-Martinsried, Germany
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | | | - Katinka Bünger
- Plant Biochemistry, LMU Munich, Planegg-Martinsried, Germany
| | - Beata Szulc
- Plant Biochemistry, LMU Munich, Planegg-Martinsried, Germany
| | - Chance M Lewis
- School of Biological Sciences, Washington State University, Pullman, WA, USA
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5
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Westgeest AJ, Dauzat M, Simonneau T, Pantin F. Leaf starch metabolism sets the phase of stomatal rhythm. THE PLANT CELL 2023; 35:3444-3469. [PMID: 37260348 PMCID: PMC10473205 DOI: 10.1093/plcell/koad158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 04/25/2023] [Accepted: 05/15/2023] [Indexed: 06/02/2023]
Abstract
In leaves of C3 and C4 plants, stomata open during the day to favor CO2 entry for photosynthesis and close at night to prevent inefficient transpiration of water vapor. The circadian clock paces rhythmic stomatal movements throughout the diel (24-h) cycle. Leaf transitory starch is also thought to regulate the diel stomatal movements, yet the underlying mechanisms across time (key moments) and space (relevant leaf tissues) remain elusive. Here, we developed PhenoLeaks, a pipeline to analyze the diel dynamics of transpiration, and used it to screen a series of Arabidopsis (Arabidopsis thaliana) mutants impaired in starch metabolism. We detected a sinusoidal, endogenous rhythm of transpiration that overarches days and nights. We determined that a number of severe mutations in starch metabolism affect the endogenous rhythm through a phase shift, resulting in delayed stomatal movements throughout the daytime and diminished stomatal preopening during the night. Nevertheless, analysis of tissue-specific mutations revealed that neither guard-cell nor mesophyll-cell starch metabolisms are strictly required for normal diel patterns of transpiration. We propose that leaf starch influences the timing of transpiration rhythm through an interplay between the circadian clock and sugars across tissues, while the energetic effect of starch-derived sugars is usually nonlimiting for endogenous stomatal movements.
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Affiliation(s)
| | - Myriam Dauzat
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
| | | | - Florent Pantin
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers F-49000, France
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6
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Amitrano C, Paglialunga G, Battistelli A, De Micco V, Del Bianco M, Liuzzi G, Moscatello S, Paradiso R, Proietti S, Rouphael Y, De Pascale S. Defining growth requirements of microgreens in space cultivation via biomass production, morpho-anatomical and nutritional traits analysis. FRONTIERS IN PLANT SCIENCE 2023; 14:1190945. [PMID: 37538067 PMCID: PMC10394706 DOI: 10.3389/fpls.2023.1190945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/29/2023] [Indexed: 08/05/2023]
Abstract
During long-term manned missions to the Moon or Mars, the integration of astronauts' diet with fresh food rich in functional compounds, like microgreens, could strengthen their physiological defenses against the oxidative stress induced by the exposure to space factors. Therefore, the development of targeted cultivation practices for microgreens in space is mandatory, since the cultivation in small, closed facilities may alter plant anatomy, physiology, and resource utilization with species-specific responses. Here, the combined effect of two vapor pressure deficit levels (VPD: 0.14 and 1.71 kPa) and two light intensities (150 and 300 µmol photons m-2 s-1 PPFD) on two species for microgreen production (Brassica oleracea var. capitata f. sabauda 'Vertus' and Raphanus raphanistrum subsp. sativus 'Saxa'), was tested on biomass production per square meter, morpho-anatomical development, nutritional and nutraceutical properties. Microgreens were grown in fully controlled conditions under air temperature of 18/24°C, on coconut fiber mats, RGB light spectrum and 12 h photoperiod, till they reached the stage of first true leaves. At this stage microgreens were samples, for growth and morpho-anatomical analyses, and to investigate the biochemical composition in terms of ascorbic acid, phenols, anthocyanin, carotenoids, carbohydrates, as well as of anti-nutritional compounds, such as nitrate, sulfate, and phosphate. Major differences in growth were mostly driven by the species with 'Saxa' always presenting the highest fresh and dry weight as well as the highest elongation; however light intensity and VPDs influenced the anatomical development of microgreens, and the accumulation of ascorbic acid, carbohydrates, nitrate, and phosphate. Both 'Saxa' and 'Vertus' at low VPD (LV) and 150 PPFD increased the tissue thickness and synthetized high β-carotene and photosynthetic pigments. Moreover, 'Vertus' LV 150, produced the highest content of ascorbate, fundamental for nutritional properties in space environment. The differences among the treatments and their interaction suggested a relevant difference in resource use efficiency. In the light of the above, microgreens can be considered suitable for cultivation in limited-volume growth modules directly onboard, provided that all the environmental factors are combined and modulated according to the species requirements to enhance their growth and biomass production, and to achieve specific nutritional traits.
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Affiliation(s)
- Chiara Amitrano
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Naples, Italy
| | - Gabriele Paglialunga
- Research Institute on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Porano, Terni, Italy
| | - Alberto Battistelli
- Research Institute on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Porano, Terni, Italy
| | - Veronica De Micco
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Naples, Italy
| | | | - Greta Liuzzi
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Naples, Italy
| | - Stefano Moscatello
- Research Institute on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Porano, Terni, Italy
| | - Roberta Paradiso
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Naples, Italy
| | - Simona Proietti
- Research Institute on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Porano, Terni, Italy
| | - Youssef Rouphael
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Naples, Italy
| | - Stefania De Pascale
- Department of Agricultural Sciences, University of Naples Federico II, Portici, Naples, Italy
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7
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Han H, Zhou Y, Liu H, Chen X, Wang Q, Zhuang H, Sun X, Ling Q, Zhang H, Wang B, Wang J, Tang Y, Wang H, Liu H. Transcriptomics and Metabolomics Analysis Provides Insight into Leaf Color and Photosynthesis Variation of the Yellow-Green Leaf Mutant of Hami Melon ( Cucumis melo L.). PLANTS (BASEL, SWITZERLAND) 2023; 12:1623. [PMID: 37111847 PMCID: PMC10143263 DOI: 10.3390/plants12081623] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 06/16/2023]
Abstract
Leaf color mutants are ideal materials for studying the regulatory mechanism of chloroplast development and photosynthesis. We isolated a cucumis melo spontaneous mutant (MT), which showed yellow-green leaf phenotype in the whole growing period and could be inherited stably. We compared its leaves with the wild type (WT) in terms of cytology, physiology, transcriptome and metabolism. The results showed that the thylakoid grana lamellae of MT were loosely arranged and fewer in number than WT. Physiological experiments also showed that MT had less chlorophyll content and more accumulation of reactive oxygen species (ROS) than WT. Furthermore, the activity of several key enzymes in C4 photosynthetic carbon assimilation pathway was more enhanced in MT than WT. Transcriptomic and metabolomic analyses showed that differential expression genes and differentially accumulated metabolites in MT were mainly co-enriched in the pathways related to photosystem-antenna proteins, central carbon metabolism, glutathione metabolism, phenylpropanoid biosynthesis and flavonoid metabolism. We also analyzed several key proteins in photosynthesis and chloroplast transport by Western blot. In summary, the results may provide a new insight into the understanding of how plants respond to the impaired photosynthesis by regulating chloroplast development and photosynthetic carbon assimilation pathways.
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Affiliation(s)
- Hongwei Han
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Yuan Zhou
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200030, China
| | - Huifang Liu
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Xianjun Chen
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
| | - Qiang Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Hongmei Zhuang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Xiaoxia Sun
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
| | - Qihua Ling
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200030, China
| | - Huijun Zhang
- School of Life Science, Huaibei Normal University, Huaibei 235000, China
| | - Baike Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Juan Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Yaping Tang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Hao Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Huiying Liu
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
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8
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Dong X, Chen L, Yang H, Tian L, Dong F, Chai Y, Qu LQ. Pho1 cooperates with DPE1 to control short maltooligosaccharide mobilization during starch synthesis initiation in rice endosperm. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:47. [PMID: 36912930 DOI: 10.1007/s00122-023-04250-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/18/2022] [Indexed: 06/18/2023]
Abstract
Plastidial α-glucan phosphorylase is a key factor that cooperates with plastidial disproportionating enzyme to control short maltooligosaccharide mobilization during the initiation process of starch molecule synthesis in developing rice endosperm. Storage starch synthesis is essential for grain filling. However, little is known about how cereal endosperm controls starch synthesis initiation. One of core events for starch synthesis initiation is short maltooligosaccharide (MOS) mobilization consisting of long MOS primer production and excess MOS breakdown. By mutant analyses and biochemical investigations, we present here functional identifications of plastidial α-glucan phosphorylase (Pho1) and disproportionating enzyme (DPE1) during starch synthesis initiation in rice (Oryza sativa) endosperm. Pho1 deficiency impaired MOS mobilization, triggering short MOS accumulation and starch synthesis reduction during early seed development. The mutant seeds differed significantly in MOS level and starch content at 15 days after flowering and exhibited diverse endosperm phenotypes during mid-late seed development: ranging from pseudonormal to shrunken (Shr), severely or excessively Shr. The level of DPE1 was almost normal in the PN seeds but significantly reduced in the Shr seeds. Overexpression of DPE1 in pho1 resulted in plump seeds only. DPE1 deficiency had no obvious effects on MOS mobilization. Knockout of DPE1 in pho1 completely blocked MOS mobilization, resulting in severely and excessively Shr seeds only. These findings show that Pho1 cooperates with DPE1 to control short MOS mobilization during starch synthesis initiation in rice endosperm.
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Affiliation(s)
- Xiangbai Dong
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
| | - Liangke Chen
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huifang Yang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lihong Tian
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
| | - Fengqin Dong
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yaru Chai
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Le Qing Qu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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9
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Norizuki T, Minamino N, Sato M, Ueda T. Autophagy regulates plastid reorganization during spermatogenesis in the liverwort Marchantia polymorpha. FRONTIERS IN PLANT SCIENCE 2023; 14:1101983. [PMID: 36844055 PMCID: PMC9947651 DOI: 10.3389/fpls.2023.1101983] [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: 11/18/2022] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Autophagy is a highly conserved system that delivers cytoplasmic components to lysosomes/vacuoles. Plastids are also degraded through autophagy for nutrient recycling and quality control; however, the involvement of autophagic degradation of plastids in plant cellular differentiation remains unclear. Here, we investigated whether spermiogenesis, the differentiation of spermatids into spermatozoids, in the liverwort Marchantia polymorpha involves autophagic degradation of plastids. Spermatozoids of M. polymorpha possess one cylindrical plastid at the posterior end of the cell body. By fluorescently labeling and visualizing plastids, we detected dynamic morphological changes during spermiogenesis. We found that a portion of the plastid was degraded in the vacuole in an autophagy-dependent manner during spermiogenesis, and impaired autophagy resulted in defective morphological transformation and starch accumulation in the plastid. Furthermore, we found that autophagy was dispensable for the reduction in plastid number and plastid DNA elimination. These results demonstrate a critical but selective role of autophagy in plastid reorganization during spermiogenesis in M. polymorpha.
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Affiliation(s)
- Takuya Norizuki
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
- Laboratory of Molecular Membrane Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Naoki Minamino
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
| | - Miyuki Sato
- Laboratory of Molecular Membrane Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Takashi Ueda
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
- Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
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10
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Ruiz-Gayosso A, Rodríguez-Cruz I, Martínez-Barajas E, Coello P. Phosphorylation of DPE2 at S786 partially regulates starch degradation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 193:70-77. [PMID: 36335878 DOI: 10.1016/j.plaphy.2022.10.024] [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: 08/17/2022] [Revised: 10/10/2022] [Accepted: 10/22/2022] [Indexed: 06/16/2023]
Abstract
In plants, transitory starch is synthetized during the day and degraded at night to provide the continuous carbon needed for growth and development. Starch metabolism is highly coordinated, as the starch degradation rate must be coupled to the amount of starch synthetized during the day. Maltose is one of the chloroplastic products obtained from starch degradation, and maltose is exported to the cytosol where disproportionating enzyme-2 (DPE2) is responsible for its metabolism. The amount of DPE2 remained unchanged throughout the day, but its activity notably increased at the end of the day (7 p.m.), suggesting that posttranslational modification drives the mechanism underlying the regulatory activity of this enzyme. Sucrose nonfermenting-related kinase-1 (SnRK1), a protein kinase that controls the activity of several metabolic enzymes, was able to interact and phosphorylate DPE2 at three different residues localized in the α-glucanotransferase domain. This phosphorylation acts as a positive regulator of DPE2, increasing its activity. Complementation of dpe2-deficient mutants with the wild-type (WT) and S786A forms of DPE2 showed that the nonphosphorylated form of DPE2 only partially restored starch degradation, suggesting that phosphorylation at S786 is involved in enzyme regulation.
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Affiliation(s)
- A Ruiz-Gayosso
- Departamento de Bioquímica, Facultad de Química, UNAM, Cd. Mx, 04510, Mexico
| | - I Rodríguez-Cruz
- Departamento de Bioquímica, Facultad de Química, UNAM, Cd. Mx, 04510, Mexico
| | - E Martínez-Barajas
- Departamento de Bioquímica, Facultad de Química, UNAM, Cd. Mx, 04510, Mexico
| | - P Coello
- Departamento de Bioquímica, Facultad de Química, UNAM, Cd. Mx, 04510, Mexico.
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11
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Li X, Apriyanto A, Castellanos JF, Compart J, Muntaha SN, Fettke J. Dpe2/phs1 revealed unique starch metabolism with three distinct phases characterized by different starch granule numbers per chloroplast, allowing insights into the control mechanism of granule number regulation by gene co-regulation and metabolic profiling. FRONTIERS IN PLANT SCIENCE 2022; 13:1039534. [PMID: 36407636 PMCID: PMC9667719 DOI: 10.3389/fpls.2022.1039534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
An Arabidopsis mutant lacking both the cytosolic Disproportionating enzyme 2 (DPE2) and the plastidial glucan Phosphorylase 1 (PHS1) revealed a unique starch metabolism. Dpe2/phs1 has been reported to have only one starch granule number per chloroplast when grown under diurnal rhythm. For this study, we analyzed dpe2/phs1 in details following the mutant development, and found that it showed three distinct periods of granule numbers per chloroplast, while there was no obvious change observed in Col-0. In young plants, the starch granule number was similar to that in Col-0 at first, and then decreased significantly, down to one or no granule per chloroplast, followed by an increase in the granule number. Thus, in dpe2/phs1, control over the starch granule number is impaired, but it is not defective in starch granule initiation. The data also indicate that the granule number is not fixed, and is regulated throughout plant growth. Furthermore, the chloroplasts revealed alterations during these three periods, with a partially strong aberrant morphology in the middle phase. Interestingly, the unique metabolism was perpetuated when starch degradation was further impaired through an additional lack of Isoamylase 3 (ISA3) or Starch excess 4 (SEX4). Transcriptomic studies and metabolic profiling revealed the co-regulation of starch metabolism-related genes and a clear metabolic separation between the periods. Most senescence-induced genes were found to be up-regulated more than twice in the starch-less mature leaves. Thus, dpe2/phs1 is a unique plant material source, with which we may study starch granule number regulation to obtain a more detailed understanding.
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12
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Sakuraba Y. Molecular basis of nitrogen starvation-induced leaf senescence. FRONTIERS IN PLANT SCIENCE 2022; 13:1013304. [PMID: 36212285 PMCID: PMC9538721 DOI: 10.3389/fpls.2022.1013304] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 09/08/2022] [Indexed: 06/01/2023]
Abstract
Nitrogen (N), a macronutrient, is often a limiting factor in plant growth, development, and productivity. To adapt to N-deficient environments, plants have developed elaborate N starvation responses. Under N-deficient conditions, older leaves exhibit yellowing, owing to the degradation of proteins and chlorophyll pigments in chloroplasts and subsequent N remobilization from older leaves to younger leaves and developing organs to sustain plant growth and productivity. In recent years, numerous studies have been conducted on N starvation-induced leaf senescence as one of the representative plant responses to N deficiency, revealing that leaf senescence induced by N deficiency is highly complex and intricately regulated at different levels, including transcriptional, post-transcriptional, post-translational and metabolic levels, by multiple genes and proteins. This review summarizes the current knowledge of the molecular mechanisms associated with N starvation-induced leaf senescence.
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Affiliation(s)
- Yasuhito Sakuraba
- Plant Functional Biotechnology, Biotechnology Research Center, The University of Tokyo, Tokyo, Japan
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13
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Grover S, Cardona JB, Zogli P, Alvarez S, Naldrett MJ, Sattler SE, Louis J. Reprogramming of sorghum proteome in response to sugarcane aphid infestation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 320:111289. [PMID: 35643611 DOI: 10.1016/j.plantsci.2022.111289] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/12/2022] [Accepted: 04/14/2022] [Indexed: 06/15/2023]
Abstract
Sugarcane aphid (SCA; Melanaphis sacchari Zehntner) is a key piercing-sucking pest of sorghum (Sorghum bicolor) that cause significant yield losses. While feeding on host plants, complex signaling networks are invoked from recognition of insect attack to induction of plant defenses. Consequently, these signaling networks lead to the production of insecticidal compounds or limited access of nutrients to insects. Previously, several studies were published on the transcriptomics analysis of sorghum in response to SCA infestation, but no information is available on the physiological changes of sorghum at the proteome level. We used the SCA resistant sorghum genotype SC265 for the global proteomics analysis after 1 and 7 days of SCA infestation using the TMT-plex technique. Peptides matching a total of 4211 proteins were identified and 158 proteins were differentially expressed at day 1 and 7. Overall, proteome profiling of SC265 after SCA infestation at days 1 and 7 revealed the suppression of plant defense-related proteins and upregulation of plant defense and signaling-related proteins, respectively. The plant defense responses based on proteome data were validated using electrical penetration graph (EPG) technique to observe changes in aphid feeding. Feeding behavior analyses revealed that SCA spent significantly longer time in phloem phase on SCA infested plants for day 1 and lesser time in day 7 SCA infested sorghum plants, compared to their respective control plants. Overall, our study provides insights into underlying mechanisms that contribute to sorghum resistance to SCA.
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Affiliation(s)
- Sajjan Grover
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | | | - Prince Zogli
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Sophie Alvarez
- Proteomics and Metabolomics Facility, Nebraska Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Michael J Naldrett
- Proteomics and Metabolomics Facility, Nebraska Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Scott E Sattler
- Wheat, Sorghum, and Forage Research Unit, US Department of Agriculture-Agricultural Research Service, Lincoln, NE 68583, USA
| | - Joe Louis
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Department of Biochemistry, University of Nebraska-Lincoln, Lincoln NE 68583, USA.
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14
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Muntaha SN, Li X, Compart J, Apriyanto A, Fettke J. Carbon pathways during transitory starch degradation in Arabidopsis differentially affect the starch granule number and morphology in the dpe2/phs1 mutant background. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 180:35-41. [PMID: 35378390 DOI: 10.1016/j.plaphy.2022.03.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/24/2022] [Accepted: 03/26/2022] [Indexed: 06/14/2023]
Abstract
The Arabidopsis knockout mutant lacking both the cytosolic disproportionating enzyme 2 (DPE2) and the plastidial phosphorylase (PHS1) had a dwarf-growth phenotype, a reduced and uneven distribution of starch within the plant rosettes, and a lower starch granule number per chloroplast under standard growth conditions. In contrast, a triple mutant impaired in starch degradation by its additional lack of the glucan, water dikinase (GWD) showed improved plant growth, a starch-excess phenotype, and a homogeneous starch distribution. Furthermore, the number of starch granules per chloroplast was increased and was similar to the wild type. We concluded that ongoing starch degradation is mainly responsible for the observed phenotype of dpe2/phs1. Next, we generated two further triple mutants lacking either the phosphoglucan, water dikinase (PWD), or the disproportionating enzyme 1 (DPE1) in the background of the double mutant. Analysis of the starch metabolism revealed that even minor ongoing starch degradation observed in dpe2/phs1/pwd maintained the double mutant phenotype. In contrast, an additional blockage in the glucose pathway of starch breakdown, as in dpe2/phs1/dpe1, resulted in a nearly starch-free phenotype and massive chloroplast degradation. The characterized mutants were discussed in the context of starch granule formation.
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Affiliation(s)
- Sidratul Nur Muntaha
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Xiaoping Li
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Julia Compart
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Ardha Apriyanto
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany.
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15
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Wang K, Cai S, Xing Q, Qi Z, Fotopoulos V, Yu J, Zhou J. Melatonin delays dark-induced leaf senescence by inducing miR171b expression in tomato. J Pineal Res 2022; 72:e12792. [PMID: 35174545 DOI: 10.1111/jpi.12792] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/29/2022] [Accepted: 02/11/2022] [Indexed: 11/29/2022]
Abstract
Melatonin functions in multiple aspects of plant growth, development, and stress response. Nonetheless, the mechanism of melatonin in plant carbon metabolism remains largely unknown. In this study, we investigated the influence of melatonin on the degradation of starch in tomato leaves. Results showed that exogenous melatonin attenuated carbon starvation-induced chlorophyll degradation and leaf senescence. In addition, melatonin delayed leaf starch degradation and inhibited the transcription of starch-degrading enzymes after sunset. Interestingly, melatonin-alleviated symptoms of leaf senescence and starch degradation were compromised when the first key gene for starch degradation, α-glucan water dikinase (GWD), was overexpressed. Furthermore, exogenous melatonin significantly upregulated the transcript levels of several microRNAs, including miR171b. Crucially, the GWD gene was identified as a target of miR171b, and the overexpression of miR171b ameliorated the carbon starvation-induced degradation of chlorophyll and starch, and inhibited the expression of the GWD gene. Taken together, these results demonstrate that melatonin promotes plant tolerance against carbon starvation by upregulating the expression of miR171b, which can directly inhibit GWD expression in tomato leaves.
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Affiliation(s)
- Kaixin Wang
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, People's Republic of China
| | - Shuyu Cai
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, People's Republic of China
| | - Qufan Xing
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, People's Republic of China
| | - Zhenyu Qi
- Agricultural Experiment Station, Zhejiang University, Hangzhou, People's Republic of China
| | - Vasileios Fotopoulos
- Department of Agricultural Sciences Biotechnology and Food Science, Cyprus University of Technology, Lemesos, Cyprus
| | - Jingquan Yu
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, People's Republic of China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Ministry of Agriculture and Rural Affairs, Hangzhou, People's Republic of China
| | - Jie Zhou
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, People's Republic of China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Ministry of Agriculture and Rural Affairs, Hangzhou, People's Republic of China
- Shandong (Linyi) Institute of Modern Agriculture, Zhejiang University, Linyi, People's Republic of China
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16
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Woodson JD. Control of chloroplast degradation and cell death in response to stress. Trends Biochem Sci 2022; 47:851-864. [DOI: 10.1016/j.tibs.2022.03.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/25/2022] [Accepted: 03/14/2022] [Indexed: 12/16/2022]
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17
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Dhami N, Pogson BJ, Tissue DT, Cazzonelli CI. A foliar pigment-based bioassay for interrogating chloroplast signalling revealed that carotenoid isomerisation regulates chlorophyll abundance. PLANT METHODS 2022; 18:18. [PMID: 35177117 PMCID: PMC8851705 DOI: 10.1186/s13007-022-00847-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Some plastid-derived metabolites can control nuclear gene expression, chloroplast biogenesis, and chlorophyll biosynthesis. For example, norflurazon (NFZ) induced inhibition of carotenoid biosynthesis in leaves elicits a protoporphyrin IX (Mg-ProtoIX) retrograde signal that controls chlorophyll biosynthesis and chloroplast development. Carotenoid cleavage products, known as apocarotenoids, also regulate plastid development. The key steps in carotenoid biosynthesis or catabolism that can regulate chlorophyll biosynthesis in leaf tissues remain unclear. Here, we established a foliar pigment-based bioassay using Arabidopsis rosette leaves to investigate plastid signalling processes in young expanding leaves comprising rapidly dividing and expanding cells containing active chloroplast biogenesis. RESULTS We demonstrate that environmental treatments (extended darkness and cold exposure) as well as chemical (norflurazon; NFZ) inhibition of carotenoid biosynthesis, reduce chlorophyll levels in young, but not older leaves of Arabidopsis. Mutants with disrupted xanthophyll accumulation, apocarotenoid phytohormone biosynthesis (abscisic acid and strigolactone), or enzymatic carotenoid cleavage, did not alter chlorophyll levels in young or old leaves. However, perturbations in acyclic cis-carotene biosynthesis revealed that disruption of CAROTENOID ISOMERASE (CRTISO), but not ZETA-CAROTENE ISOMERASE (Z-ISO) activity, reduced chlorophyll levels in young leaves of Arabidopsis plants. NFZ-induced inhibition of PHYTOENE DESATURASE (PDS) activity caused higher phytoene accumulation in younger crtiso leaves compared to WT indicating a continued substrate supply from the methylerythritol 4-phosphate (MEP) pathway. CONCLUSION The Arabidopsis foliar pigment-based bioassay can be used to differentiate signalling events elicited by environmental change, chemical treatment, and/or genetic perturbation, and determine how they control chloroplast biogenesis and chlorophyll biosynthesis. Genetic perturbations that impaired xanthophyll biosynthesis and/or carotenoid catabolism did not affect chlorophyll biosynthesis. The lack of CAROTENOID ISOMERISATION reduced chlorophyll accumulation, but not phytoene biosynthesis in young leaves of Arabidopsis plants growing under a long photoperiod. Findings generated using the newly customised foliar pigment-based bioassay implicate that carotenoid isomerase activity and NFZ-induced inhibition of PDS activity elicit different signalling pathways to control chlorophyll homeostasis in young leaves of Arabidopsis.
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Affiliation(s)
- N Dhami
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- School of Health and Allied Sciences, Pokhara University, Pokhara 30, Kaski, Gandaki, 33700, Nepal
| | - B J Pogson
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - D T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - C I Cazzonelli
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
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18
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Wen YX, Wang JY, Zhu HH, Han GH, Huang RN, Huang L, Hong YG, Zheng SJ, Yang JL, Chen WW. Potential Role of Domains Rearranged Methyltransferase7 in Starch and Chlorophyll Metabolism to Regulate Leaf Senescence in Tomato. FRONTIERS IN PLANT SCIENCE 2022; 13:836015. [PMID: 35211145 PMCID: PMC8860812 DOI: 10.3389/fpls.2022.836015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
Deoxyribonucleic acid (DNA) methylation is an important epigenetic mark involved in diverse biological processes. Here, we report the critical function of tomato (Solanum lycopersicum) Domains Rearranged Methyltransferase7 (SlDRM7) in plant growth and development, especially in leaf interveinal chlorosis and senescence. Using a hairpin RNA-mediated RNA interference (RNAi), we generated SlDRM7-RNAi lines and observed pleiotropic developmental defects including small and interveinal chlorosis leaves. Combined analyses of whole genome bisulfite sequence (WGBS) and RNA-seq revealed that silencing of SlDRM7 caused alterations in both methylation levels and transcript levels of 289 genes, which are involved in chlorophyll synthesis, photosynthesis, and starch degradation. Furthermore, the photosynthetic capacity decreased in SlDRM7-RNAi lines, consistent with the reduced chlorophyll content and repression of genes involved in chlorophyll biosynthesis, photosystem, and photosynthesis. In contrast, starch granules were highly accumulated in chloroplasts of SlDRM7-RNAi lines and associated with lowered expression of genes in the starch degradation pathway. In addition, SlDRM7 was activated by aging- and dark-induced senescence. Collectively, these results demonstrate that SlDRM7 acts as an epi-regulator to modulate the expression of genes related to starch and chlorophyll metabolism, thereby affecting leaf chlorosis and senescence in tomatoes.
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Affiliation(s)
- Yu Xin Wen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jia Yi Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Hui Hui Zhu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Guang Hao Han
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Ru Nan Huang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Li Huang
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
| | - Yi Guo Hong
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Shao Jian Zheng
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jian Li Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Wei Wei Chen
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
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19
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Salmeron-Santiago IA, Martínez-Trujillo M, Valdez-Alarcón JJ, Pedraza-Santos ME, Santoyo G, Pozo MJ, Chávez-Bárcenas AT. An Updated Review on the Modulation of Carbon Partitioning and Allocation in Arbuscular Mycorrhizal Plants. Microorganisms 2021; 10:75. [PMID: 35056524 PMCID: PMC8781679 DOI: 10.3390/microorganisms10010075] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/24/2021] [Accepted: 12/27/2021] [Indexed: 12/29/2022] Open
Abstract
Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs that supply mineral nutrients to the host plant in exchange for carbon derived from photosynthesis. Sucrose is the end-product of photosynthesis and the main compound used by plants to translocate photosynthates to non-photosynthetic tissues. AMF alter carbon distribution in plants by modifying the expression and activity of key enzymes of sucrose biosynthesis, transport, and/or catabolism. Since sucrose is essential for the maintenance of all metabolic and physiological processes, the modifications addressed by AMF can significantly affect plant development and stress responses. AMF also modulate plant lipid biosynthesis to acquire storage reserves, generate biomass, and fulfill its life cycle. In this review we address the most relevant aspects of the influence of AMF on sucrose and lipid metabolism in plants, including its effects on sucrose biosynthesis both in photosynthetic and heterotrophic tissues, and the influence of sucrose on lipid biosynthesis in the context of the symbiosis. We present a hypothetical model of carbon partitioning between plants and AMF in which the coordinated action of sucrose biosynthesis, transport, and catabolism plays a role in the generation of hexose gradients to supply carbon to AMF, and to control the amount of carbon assigned to the fungus.
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Affiliation(s)
| | | | - Juan J. Valdez-Alarcón
- Centro Multidisciplinario de Estudios en Biotecnología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia 58880, Mexico;
| | - Martha E. Pedraza-Santos
- Facultad de Agrobiología “Presidente Juárez”, Universidad Michoacana de San Nicolás de Hidalgo, Uruapan 60170, Mexico;
| | - Gustavo Santoyo
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia 58030, Mexico;
| | - María J. Pozo
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, 18008 Granada, Spain
| | - Ana T. Chávez-Bárcenas
- Facultad de Agrobiología “Presidente Juárez”, Universidad Michoacana de San Nicolás de Hidalgo, Uruapan 60170, Mexico;
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20
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Ignat T, De Falco N, Berger-Tal R, Rachmilevitch S, Karnieli A. A novel approach for long-term spectral monitoring of desert shrubs affected by an oil spill. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 289:117788. [PMID: 34332167 DOI: 10.1016/j.envpol.2021.117788] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 07/08/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Crude oil pollution is a global environmental concern since it persists in the environment longer than most conventional carbon sources. In December 2014, the hyper-arid Evrona Nature Reserve, Israel, experienced large-scale contamination when crude oil spilled. The overarching goal of the study was to investigate the possible changes, caused by an accidental crude oil spill, in the leaf reflectance and biochemical composition of four natural habitat desert shrubs. The specific objectives were (1) to monitor the biochemical properties of dominant shrub species in the polluted and control areas; (2) to study the long-term consequences of the contamination; (3) to provide information that will assist in planning rehabilitation actions; and (4) to explore the feasibility of vegetation indices (VIs), along with the machine learning (ML) technique, for detecting stressed shrubs based on the full spectral range. Four measurement campaigns were conducted in 2018 and 2019. Along with the various stress indicators, field spectral measurements were performed in the range of 350-2500 nm. A regression analysis to examine the relation of leaf reflectance to biochemical contents was carried out, to reveal the relevant wavelengths in which polluted and control plants differ. Vegetation indices applied in previous studies were found to be less sensitive for indirect detection of long-term oil contamination. A novel spectral index, based on indicative spectral bands, named the "normalized blue-green stress index" (NBGSI), was established. The NBGSI distinguished significantly between shrubs located in the polluted and in the control areas. The NBGSI showed a strong linear correlation with pheophytin a. Machine learning classification algorithms obtained high overall prediction accuracy in distinguishing between shrubs located in the oil-polluted and the control sites, indicating internal component differences. The findings of this study demonstrate the efficacy of indirect and non-destructive spectral tools for detecting and monitoring oil pollution stress in shrubs.
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Affiliation(s)
- Timea Ignat
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel
| | - Natalie De Falco
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel
| | - Reut Berger-Tal
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel
| | - Shimon Rachmilevitch
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel
| | - Arnon Karnieli
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel.
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21
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Schreier TB, Fahy B, David LC, Siddiqui H, Castells-Graells R, Smith AM. Introduction of glucan synthase into the cytosol in wheat endosperm causes massive maltose accumulation and represses starch synthesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1431-1442. [PMID: 33764607 DOI: 10.1111/tpj.15246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 06/12/2023]
Abstract
We expressed a bacterial glucan synthase (Agrobacterium GlgA) in the cytosol of developing endosperm cells in wheat grains, to discover whether it could generate a glucan from cytosolic ADP-glucose. Transgenic lines had high glucan synthase activity during grain filling, but did not accumulate glucan. Instead, grains accumulated very high concentrations of maltose. They had large volumes during development due to high water content, and very shrivelled grains at maturity. Starch synthesis was severely reduced. We propose that cytosolic glucan synthesized by the glucan synthase was immediately hydrolysed to maltose by cytosolic β-amylase(s). Maltose accumulation resulted in a high osmotic potential in developing grain, drawing in excess water that stretched the seed coat and pericarp. Loss of water during grain maturation then led to shrinkage when the grains matured. Maltose accumulation is likely to account for the reduced starch synthesis in transgenic grains, through signalling and toxic effects. Using bioinformatics, we identify an isoform of β-amylase likely to be responsible for maltose accumulation. Removal of this isoform through identification of TILLING mutants or genome editing, combined with co-expression of heterologous glucan synthase and a glucan branching enzyme, may in future enable elevated yields of carbohydrate through simultaneous accumulation of starch and cytosolic glucan.
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Affiliation(s)
- Tina B Schreier
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
- Department of Plant Sciences, University of Cambridge, Downing St, Cambridge, CB2 3EA, UK
| | - Brendan Fahy
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Laure C David
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
- ETH Department of Biology, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Hamad Siddiqui
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
- Germains Seed Technology, Lab 7, Centrum, Norwich Research Park, Norwich, NR4 7UG, UK
| | - Roger Castells-Graells
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Alison M Smith
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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22
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Liesche J, Vincent C, Han X, Zwieniecki M, Schulz A, Gao C, Bravard R, Marker S, Bohr T. The mechanism of sugar export from long conifer needles. THE NEW PHYTOLOGIST 2021; 230:1911-1924. [PMID: 33638181 DOI: 10.1111/nph.17302] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
The green leaves of plants are optimised for carbon fixation and the production of sugars, which are used as central units of carbon and energy throughout the plant. However, there are physical limits to this optimisation that remain insufficiently understood. Here, quantitative anatomical analysis combined with mathematical modelling and sugar transport rate measurements were used to determine how effectively sugars are exported from the needle-shaped leaves of conifers in relation to leaf length. Mathematical modelling indicated that phloem anatomy constrains sugar export in long needles. However, we identified two mechanisms by which this constraint is overcome, even in needles longer than 20 cm: (1) the grouping of transport conduits, and (2) a shift in the diurnal rhythm of sugar metabolism and export in needle tips. The efficiency of sugar transport in the phloem can have a significant influence on leaf function. The constraints on sugar export described here for conifer needles are likely to also be relevant in other groups of plants, such as grasses and angiosperm trees.
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Affiliation(s)
- Johannes Liesche
- College of Life Sciences & Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Taicheng Road 3, Yangling, 712100, China
- Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, Düsseldorf, 40225, Germany
| | - Christopher Vincent
- Department of Horticultural Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA
| | - Xiaoyu Han
- College of Life Sciences & Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Taicheng Road 3, Yangling, 712100, China
| | - Maciej Zwieniecki
- Department of Plant Sciences, University of California, Davis One Shields Avenue, Davis, CA, 95616, USA
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg, 1871, Denmark
| | - Chen Gao
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg, 1871, Denmark
| | - Rodrigue Bravard
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Sean Marker
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Tomas Bohr
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
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Cvetkovic J, Haferkamp I, Rode R, Keller I, Pommerrenig B, Trentmann O, Altensell J, Fischer-Stettler M, Eicke S, Zeeman SC, Neuhaus HE. Ectopic maltase alleviates dwarf phenotype and improves plant frost tolerance of maltose transporter mutants. PLANT PHYSIOLOGY 2021; 186:315-329. [PMID: 33650638 PMCID: PMC8154053 DOI: 10.1093/plphys/kiab082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/25/2021] [Indexed: 05/06/2023]
Abstract
Maltose, the major product of starch breakdown in Arabidopsis (Arabidopsis thaliana) leaves, exits the chloroplast via the maltose exporter1 MEX1. Consequently, mex1 loss-of-function plants exhibit substantial maltose accumulation, a starch-excess phenotype and a specific chlorotic phenotype during leaf development. Here, we investigated whether the introduction of an alternative metabolic route could suppress the marked developmental defects typical for mex1 loss-of-function mutants. To this end, we ectopically expressed in mex1 chloroplasts a functional maltase (MAL) from baker's yeast (Saccharomyces cerevisiae, chloroplastidial MAL [cpMAL] mutants). Remarkably, the stromal MAL activity substantially alleviates most phenotypic peculiarities typical for mex1 plants. However, the cpMAL lines contained only slightly less maltose than parental mex1 plants and their starch levels were, surprisingly, even higher. These findings point to a threshold level of maltose responsible for the marked developmental defects in mex1. While growth and flowering time were only slightly retarded, cpMAL lines exhibited a substantially improved frost tolerance, when compared to wild-types. In summary, these results demonstrate the possibility to bypass the MEX1 transporter, allow us to differentiate between possible starch-excess and maltose-excess responses, and demonstrate that stromal maltose accumulation prevents frost defects. The latter insight may be instrumental for the development of crop plants with improved frost tolerance.
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Affiliation(s)
- Jelena Cvetkovic
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
| | - Ilka Haferkamp
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
| | - Regina Rode
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
| | - Isabel Keller
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
| | - Benjamin Pommerrenig
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
| | - Oliver Trentmann
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
| | - Jacqueline Altensell
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
| | | | - Simona Eicke
- Institute of Molecular Plant Biology, ETH Zürich, Universitätsstr. 2, 8092 Zurich, Switzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, ETH Zürich, Universitätsstr. 2, 8092 Zurich, Switzerland
| | - H Ekkehard Neuhaus
- Plant Physiology, University of Kaiserslautern, Erwin-Schrödinger-Str., D-67653 Kaiserslautern, Germany
- Author for communication:
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Dong H, Hu C, Liu C, Wang J, Zhou Y, Yu J. ELONGATED HYPOCOTYL 5 mediates blue light-induced starch degradation in tomato. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:2627-2641. [PMID: 33377142 DOI: 10.1093/jxb/eraa604] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/24/2020] [Indexed: 05/25/2023]
Abstract
Starch is the major storage carbohydrate in plants, and its metabolism in chloroplasts depends mainly on light. However, the mechanism through which photoreceptors regulate starch metabolism in chloroplasts is unclear. In this study, we found that the cryptochrome 1a (CRY1a)-mediated blue light signal is critical for regulating starch accumulation by inducing starch degradation through the transcription factor HY5 in chloroplasts in tomato. cry1a mutants and HY5-RNAi plants accumulated more starch and presented lower transcript levels of starch degradation-related genes in their leaves than wild-type plants. Blue light significantly induced the transcription of starch degradation-related genes in wild-type and CRY1a- or HY5-overexpressing plants but had little effect in cry1a and HY5-RNAi plants. Dual-luciferase assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation-qPCR revealed that HY5 could activate the starch degradation-related genes PWD, BAM1, BAM3, BAM8, MEX1, and DPE1 by directly binding to their promoters. Silencing of HY5 and these starch degradation-related genes in CRY1a-overexpressing plants led to increased accumulation of starch and decreased accumulation of soluble sugars. The findings presented here not only deepen our understanding of how light controls starch degradation and sugar accumulation but also allow us to explore potential targets for improving crop quality.
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Affiliation(s)
- Han Dong
- College of Horticulture, Northwest Agriculture & Forestry University, Yangling, Shaanxi, China
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Chaoyi Hu
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Chaochao Liu
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Jiachun Wang
- College of Horticulture, Northwest Agriculture & Forestry University, Yangling, Shaanxi, China
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Yanhong Zhou
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Hangzhou, China
| | - Jingquan Yu
- College of Horticulture, Northwest Agriculture & Forestry University, Yangling, Shaanxi, China
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Hangzhou, China
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Compart J, Li X, Fettke J. Starch-A complex and undeciphered biopolymer. JOURNAL OF PLANT PHYSIOLOGY 2021; 258-259:153389. [PMID: 33652172 DOI: 10.1016/j.jplph.2021.153389] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Starch is a natural storage carbohydrate in plants and algae. It consists of two relatively simple homo-biopolymers, amylopectin and amylose, with only α-1,4 and α-1,6 linked glucosyl units. Starch is an essential source of nutrition and animal food, as well as an important raw material for industry. However, despite increasing knowledge, detailed information about its structure and turnover are largely lacking. In the last decades, most data were generated using bulk experiments, a method which obviously presents limitations regarding a deeper understanding of the starch metabolism. Here, we discuss some unavoidable questions arising from the existing data. We focus on a few examples related to starch biosynthesis, degradation, and structure - where these limitations strongly emerge. Closing these knowledge gaps will also be extremely important for taking the necessary steps in order to set up starch-providing crops for the challenges of the ongoing climate changes, as well as for increasing the usability of starches for industrial applications by biotechnology.
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Affiliation(s)
- Julia Compart
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, 14476, Potsdam-Golm, Germany
| | - Xiaoping Li
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, 14476, Potsdam-Golm, Germany
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, 14476, Potsdam-Golm, Germany.
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26
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Lu X, Chen Z, Deng X, Gu M, Zhu Z, Ren J, Fu S. Transcriptomic and metabolomic analyses of non-structural carbohydrates in red maple leaves. Funct Integr Genomics 2021; 21:265-281. [PMID: 33611764 DOI: 10.1007/s10142-021-00776-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 02/03/2023]
Abstract
Plant sugars serve to balance nutrition, regulate development, and respond to biotic and abiotic stresses, whereas non-structural carbohydrates (NSCs) are essential energy sources that facilitate plant growth, metabolism, and environmental adaptation. To better elucidate the mechanisms of NSCs in red maple, ultrahigh-performance liquid chromatograph Q extractive mass spectrometry (UHPLC-QE-MS) and high-throughput RNA-sequencing were performed on green, red, and yellow leaves from a selected red maple mutant. In green leaves, the fructose phosphorylation process exhibited greater flux. In yellow leaves, sucrose and starch had a stronger capacity for synthesis and degradation, whereas in red leaves, there was a greater accumulation of trehalose and manninotriose. ArTPS5 positively regulated amylose, which was negatively regulated by ArFBP2, whereas ArFRK2 and ArFBP13 played a positive role in the biosynthesis of Sucrose-6P. Sucrose-6P also regulated anthocyanins and abscisic acid in red maple by affecting transcription factors. The results of this paper can assist with the control and optimization of the biosynthesis of NSCs in red maple, which may ultimately provide the foundation for influencing sugar production in Acer.
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Affiliation(s)
- Xiaoyu Lu
- School of Forestry and Landscape Architecture, Anhui Agricultural University, 130 West Changjiang Rd., Hefei, Anhui, 230036, People's Republic of China.,Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 South Agricultural Rd., Hefei, Anhui, 230001, People's Republic of China
| | - Zhu Chen
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 South Agricultural Rd., Hefei, Anhui, 230001, People's Republic of China
| | - Xinyi Deng
- College of Horticulture, Anhui Agricultural University, 130 West Changjiang Rd., Hefei, Anhui, 230036, People's Republic of China
| | - Mingyuan Gu
- School of Forestry and Landscape Architecture, Anhui Agricultural University, 130 West Changjiang Rd., Hefei, Anhui, 230036, People's Republic of China
| | - Zhiyong Zhu
- Ningbo City College of Vocational Technology, Ningbo, 315502, People's Republic of China
| | - Jie Ren
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 South Agricultural Rd., Hefei, Anhui, 230001, People's Republic of China.
| | - Songling Fu
- School of Forestry and Landscape Architecture, Anhui Agricultural University, 130 West Changjiang Rd., Hefei, Anhui, 230036, People's Republic of China.
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27
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Variations of Structural and Functional Traits of Azolla pinnata R. Br. in Response to Crude Oil Pollution in Arid Regions. SUSTAINABILITY 2021. [DOI: 10.3390/su13042142] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In oil-producing countries, water pollution by crude petroleum oil frequently occurs and causes many environmental problems. This study aims to investigate the effect of crude petroleum oil on the growth and functional trails of the economically important freshwater plant Azolla pinnata R. Br. and to report on the plant’s resistance to this abiotic stress. Plants were raised in an open greenhouse experiment under different levels of crude oil pollution ranging from 0.5 to 2.0 g/L. Plant functional traits were monitored over a three-week period. Plant cover of A. pinnata was decreased with the increased levels of oil pollution. The total chlorophyll content decreased from 0.76 mg/g fresh weight under 2 g/L oil treatment after 21 days of growth. The chlorophyll a/b ratio exceeded the unity at crude oil treatments above 1 g/L, with values reaching 2.78 after seven days, while after 21 days, the ratio ranged from 1.14 to 1.31. The carotenoid content ranged from 0.17 mg/g in the control to 0.11 mg/g in the 2 g/L oil treatment. The carotenoid content varied over time in relation to DNA% damage, which increased from 3.63% in the control to 11.36% in the highest oil treatment level of 2 g/L. The crude oil stress caused severe damage in the frond tissues and chloroplast structure of A. pinnata, including a less compacted palisade, the malformation of the epidermis, the disintegration of parenchyma tissue, and the lysis and malformation of the chloroplasts. Since A. pinnata cannot withstand high concentrations of crude oil pollution, it is for use in the remediation of slightly polluted freshwaters up to 0.5 g/L.
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da Silva JR, Boaretto RM, Lavorenti JAL, dos Santos BCF, Coletta-Filho HD, Mattos D. Effects of Deficit Irrigation and Huanglongbing on Sweet Orange Trees. FRONTIERS IN PLANT SCIENCE 2021; 12:731314. [PMID: 34721459 PMCID: PMC8554030 DOI: 10.3389/fpls.2021.731314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 09/14/2021] [Indexed: 05/21/2023]
Abstract
This study addresses the interactive effects of deficit irrigation and huanglongbing (HLB) infection on the physiological, biochemical, and oxidative stress responses of sweet orange trees. We sought to answer: (i) What are the causes for the reduction in water uptake in HLB infected plants? (ii) Is the water status of plants negatively affected by HLB infection? (iii) What are the key physiological traits impaired in HLB-infected plants? and (iv) What conditions can mitigate both disease severity and physiological/biochemical impairments in HLB-infected plants? Two water management treatments were applied for 11 weeks to 1-year-old-trees that were either healthy (HLB-) or infected with HLB (+) and grown in 12-L pots. Half of the trees were fully irrigated (FI) to saturation, whereas half were deficit-irrigated (DI) using 40% of the water required to saturate the substrate. Our results demonstrated that: reduced water uptake capacity in HLB+ plants was associated with reduced root growth, leaf area, stomatal conductance, and transpiration. Leaf water potential was not negatively affected by HLB infection. HLB increased leaf respiration rates (ca. 41%) and starch synthesis, downregulated starch breakdown, blocked electron transport, improved oxidative stress, and reduced leaf photosynthesis (ca. 57%) and photorespiration (ca.57%). Deficit irrigation reduced both leaf respiration (ca. 45%) and accumulation of starch (ca.53%) by increasing maltose (ca. 20%), sucrose, glucose, and fructose contents in the leaves, decreasing bacterial population (ca. 9%) and triggering a series of protective measures against further impairments in the physiology and biochemistry of HLB-infected plants. Such results provide a more complete physiological and biochemical overview of HLB-infected plants and can guide future studies to screen genetic tolerance to HLB and improve management strategies under field orchard conditions.
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29
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Mathur J. Review: Morphology, behaviour and interactions of organelles. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 301:110662. [PMID: 33218631 DOI: 10.1016/j.plantsci.2020.110662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/12/2020] [Accepted: 08/31/2020] [Indexed: 06/11/2023]
Abstract
High quality transmission electron micrographs have played a major role in shaping our views on organelles in plant cells. However, these snapshots of dead, fixed and sectioned tissue do not automatically convey an appreciation of the dynamic nature of organelles in living cells. Advances in the imaging of subcellular structures in living cells using multicoloured, targeted fluorescent proteins reveal considerable changes in organelle pleomorphy that might be limited to small regions of the cell. The fresh data and insights also challenge several existing ideas on organelle behaviour and interactivity. Here, using succinct examples from plastids, mitochondria, peroxisomes, and the endoplasmic reticulum I present an evolving view of subcellular dynamics in the plant cell.
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Affiliation(s)
- Jaideep Mathur
- Laboratory of Plant Development and Interactions, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road, Guelph, Ontario, N1G2W1, Canada
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30
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Frey LA, Baumann P, Aasen H, Studer B, Kölliker R. A Non-destructive Method to Quantify Leaf Starch Content in Red Clover. FRONTIERS IN PLANT SCIENCE 2020; 11:569948. [PMID: 33178239 PMCID: PMC7593268 DOI: 10.3389/fpls.2020.569948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Grassland-based ruminant livestock production provides a sustainable alternative to intensive production systems relying on concentrated feeds. However, grassland-based roughage often lacks the energy content required to meet the productivity potential of modern livestock breeds. Forage legumes, such as red clover, with increased starch content could partly replace maize and cereal supplements. However, breeding for increased starch content requires efficient phenotyping methods. This study is unique in evaluating a non-destructive hyperspectral imaging approach to estimate leaf starch content in red clover for enabling efficient development of high starch red clover genotypes. We assessed prediction performance of partial least square regression models (PLSR) using cross-validation, and validated model performance with an independent test set under controlled conditions. Starch content of the training set ranged from 0.1 to 120.3 mg g-1 DW. The best cross-validated PLSR model explained 56% of the measured variation and yielded a root mean square error (RMSE) of 17 mg g-1 DW. Model performance decreased when applying the trained model on the independent test set (RMSE = 29 mg g-1 DW, R 2 = 0.36). Different variable selection methods did not increase model performance. Once validated in the field, the non-destructive spectral method presented here has the potential to detect large differences in leaf starch content of red clover genotypes. Breeding material could be sampled and selected according to their starch content without destroying the plant.
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Affiliation(s)
- Lea Antonia Frey
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - Philipp Baumann
- Sustainable Agroecosystems, Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - Helge Aasen
- Crop Science, Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - Bruno Studer
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
| | - Roland Kölliker
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
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Li J, Chen G, Zhang J, Shen H, Kang J, Feng P, Xie Q, Hu Z. Suppression of a hexokinase gene, SlHXK1, leads to accelerated leaf senescence and stunted plant growth in tomato. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110544. [PMID: 32771157 DOI: 10.1016/j.plantsci.2020.110544] [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: 12/27/2019] [Revised: 05/19/2020] [Accepted: 05/27/2020] [Indexed: 05/18/2023]
Abstract
Sugars are the key regulatory molecules that impact diverse biological processes in plants. Hexokinase, the key rate-limiting enzyme in hexose metabolism, takes part in the first step of glycolytic pathway. Acting as a sensor that mediates sugar regulation, hexokinase has been proved to play significant roles in regulating plant growth and development. Here, we isolated a hexokinase gene SlHXK1 from tomato. Its transcript levels were higher in flowers and leaves than in other organs and decreased during leaf and petiole development. SlHXK1-RNAi lines displayed advanced leaf senescence and stunted plant growth. Physiological features including plant height, leaf length, thickness and size, the contents of chlorophyll, starch and MDA, and hexokinase activity were dramatically altered in SlHXK1-RNAi plants. Dark-induced leaf senescence were advanced and the transcripts of senescence-related genes after darkness treatment were markedly increased in SlHXK1-RNAi plants. RNA-seq and qRT-PCR analyses showed that the transcripts of genes related to plant hormones, photosynthesis, chloroplast development, chlorophyll synthesis and metabolism, cellular process, starch and sucrose metabolism, and senescence were significantly altered in SlHXK1-RNAi plants. Taken together, our data demonstrate that SlHXK1 is a significant gene involved in leaf senescence and plant growth and development in tomato through affecting starch turnover.
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Affiliation(s)
- Jing Li
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Guoping Chen
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Jianling Zhang
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Hui Shen
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Jing Kang
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Panpan Feng
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Qiaoli Xie
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Zongli Hu
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
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32
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Badstöber J, Gachon CMM, Ludwig-Müller J, Sandbichler AM, Neuhauser S. Demystifying biotrophs: FISHing for mRNAs to decipher plant and algal pathogen-host interaction at the single cell level. Sci Rep 2020; 10:14269. [PMID: 32868853 PMCID: PMC7459097 DOI: 10.1038/s41598-020-70884-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 08/05/2020] [Indexed: 12/18/2022] Open
Abstract
Plant-pathogen interactions follow spatial and temporal developmental dynamics where gene expression in pathogen and host undergo crucial changes. Therefore, it is of great interest to detect, quantify and localise where and when key genes are active to understand these processes. Many pathosystems are not accessible for genetic amendments or other spatially-resolved gene expression monitoring methods. Here, we adapt single molecule FISH techniques to demonstrate the presence and activity of mRNAs at the single-cell level using phytomyxids in their plant and algal host in lab and field material. This allowed us to monitor and quantify the expression of genes from the clubroot pathogen Plasmodiophora brassicae, several species of its Brassica hosts, and of several brown algae, including the genome model Ectocarpus siliculosus, infected with the phytomyxid Maullinia ectocarpii. We show that mRNAs are localised along a spatiotemporal gradient, thus providing a proof-of-concept of the usefulness of single-molecule FISH to increase knowledge about the interactions between plants, algae and phytomyxids. The methods used are easily applicable to any interaction between microbes and their algal or plant host, and have therefore the potential to rapidly increase our understanding of key, spatially- and temporally-resolved processes underpinning complex plant-microbe interactions.
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Affiliation(s)
- Julia Badstöber
- Institute of Microbiology, University of Innsbruck, 6020, Innsbruck, Austria
| | - Claire M M Gachon
- The Scottish Association for Marine Science, Scottish Marine Institute, Oban, PA37 1QA, UK
- UMR 7245 - Molécules de Communication et Adaptation des Micro-organismes, Muséum National d'Histoire Naturelle, CNRS, Paris, 75005, France
| | - Jutta Ludwig-Müller
- Institute of Botany, Technische Universität Dresden, 01217, Dresden, Germany
| | | | - Sigrid Neuhauser
- Institute of Microbiology, University of Innsbruck, 6020, Innsbruck, Austria.
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33
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Hu J, Wu X, Wu F, Chen W, White JC, Yang Y, Wang B, Xing B, Tao S, Wang X. Potential application of titanium dioxide nanoparticles to improve the nutritional quality of coriander (Coriandrum sativum L.). JOURNAL OF HAZARDOUS MATERIALS 2020; 389:121837. [PMID: 31848091 DOI: 10.1016/j.jhazmat.2019.121837] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 11/01/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
TiO2 nanoparticles (nTiO2) have been widely used in many disciplines. However, whether they can be used to improve crops growth and nutritional quality is unknown. In this study, coriander (Coriandrum sativum L.) was treated with 0, 50, 100, 200, and 400 mg/L nTiO2 to evaluate their possible benefit to plant growth and nutritional quality under hydroponic conditions. Our observations showed that 50 mg/L nTiO2 only slightly but insignificantly increased the root and shoot fresh biomass by 13.2 % and 4.1 %, respectively, relative to the control. nTiO2 at this level promoted shoot K, Ca, Mg, Fe, Mn, Zn, and B accumulation, while spatial distribution of K, Ca, Fe, Mn, Cu and Zn in coriander leaves was not affected. No nTiO2 internalization or translocation to shoots occurred. 400 mg/L nTiO2 significantly reduced root fresh biomass by 15.8 % and water content by 6.7 %. Moreover, this high dose induced root cell membrane wrinkling, attributable to their aggregation and adsorption on root surfaces. At 100-400 mg/L, antioxidant defense systems (SOD, CAT and APX) in plant were triggered to alleviate oxidative stress. At an appropriate dose (50 mg/L), nTiO2 can improve nutrient quality of edible tissues without exerting toxicity to plant or posing health risk to consumers.
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Affiliation(s)
- Jing Hu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Xinyi Wu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Fan Wu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Weixiao Chen
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Jason C White
- Department of Analytical Chemistry, The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - Yu Yang
- Department of Civil and Environmental Engineering, University of Nevada, Reno, NV 89557, USA
| | - Bin Wang
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA
| | - Shu Tao
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Xilong Wang
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
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34
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Smith AM, Zeeman SC. Starch: A Flexible, Adaptable Carbon Store Coupled to Plant Growth. ANNUAL REVIEW OF PLANT BIOLOGY 2020; 71:217-245. [PMID: 32075407 DOI: 10.1146/annurev-arplant-050718-100241] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Research in the past decade has uncovered new and surprising information about the pathways of starch synthesis and degradation. This includes the discovery of previously unsuspected protein families required both for processes and for the long-sought mechanism of initiation of starch granules. There is also growing recognition of the central role of leaf starch turnover in making carbon available for growth across the day-night cycle. Sophisticated systems-level control mechanisms involving the circadian clock set rates of nighttime starch mobilization that maintain a steady supply of carbon until dawn and modulate partitioning of photosynthate into starch in the light, optimizing the fraction of assimilated carbon that can be used for growth. These discoveries also uncover complexities: Results from experiments with Arabidopsis leaves in conventional controlled environments are not necessarily applicable to other organs or species or to growth in natural, fluctuating environments.
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Affiliation(s)
| | - Samuel C Zeeman
- Institute of Plant Molecular Biology, ETH Zürich, 8092 Zürich, Switzerland
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35
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Genome-wide association mapping of leaf mass traits in a Vietnamese rice landrace panel. PLoS One 2019; 14:e0219274. [PMID: 31283792 PMCID: PMC6613685 DOI: 10.1371/journal.pone.0219274] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/19/2019] [Indexed: 11/19/2022] Open
Abstract
Leaf traits are often strongly correlated with yield, which poses a major challenge in rice breeding. In the present study, using a panel of Vietnamese rice landraces genotyped with 21,623 single-nucleotide polymorphism markers, a genome-wide association study (GWAS) was conducted for several leaf traits during the vegetative stage. Vietnamese landraces are often poorly represented in panels used for GWAS, even though they are adapted to contrasting agrosystems and can contain original, valuable genetic determinants. A panel of 180 rice varieties was grown in pots for four weeks with three replicates under nethouse conditions. Different leaf traits were measured on the second fully expanded leaf of the main tiller, which often plays a major role in determining the photosynthetic capacity of the plant. The leaf fresh weight, turgid weight and dry weight were measured; then, from these measurements, the relative tissue weight and leaf dry matter percentage were computed. The leaf dry matter percentage can be considered a proxy for the photosynthetic efficiency per unit leaf area, which contributes to yield. By a GWAS, thirteen QTLs associated with these leaf traits were identified. Eleven QTLs were identified for fresh weight, eleven for turgid weight, one for dry weight, one for relative tissue weight and one for leaf dry matter percentage. Eleven QTLs presented associations with several traits, suggesting that these traits share common genetic determinants, while one QTL was specific to leaf dry matter percentage and one QTL was specific to relative tissue weight. Interestingly, some of these QTLs colocalize with leaf- or yield-related QTLs previously identified using other material. Several genes within these QTLs with a known function in leaf development or physiology are reviewed.
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36
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You WJ, Feng YR, Shen YH, Chen YR, Chen TY, Fu SF. Silencing of NbCMT3s has Pleiotropic Effects on Development by Interfering with Autophagy-Related Genes in Nicotiana benthamiana. PLANT & CELL PHYSIOLOGY 2019; 60:1120-1135. [PMID: 30785195 DOI: 10.1093/pcp/pcz034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/14/2019] [Indexed: 05/25/2023]
Abstract
DNA methylation is a chromatin mark that has a crucial role in regulating gene expression. The chromomethylase (CMT) protein family is a plant-specific DNA methyltransferase that mediates growth and development. However, the roles of CMT3 in autophagy remain to be elucidated. Here, we identified the potential targets of CMT3 in Nicotiana benthamiana (NbCMT3) during developmental programs. Virus-induced gene silencing of NbCMT3/3-2 in N. benthamiana had pleiotropic effects on plant morphology, which indicates its indispensible role in development. Genome-wide transcriptome analysis of NbCMT3/3-2-silenced plants revealed interference with genes related to autophagy and ubiquitination. The expression of NbBeclin 1 and NbHRD1B was higher in NbCMT3/3-2-silenced than control plants. The formation of autophagosomes and starch degradation was disrupted in NbCMT3/3-2-silenced plants, which implies a perturbed autophagic processes. We further generated transgenic N. benthamiana plants carrying a chimeric promoter-reporter construct linking the NbBeclin 1 promoter region and β-glucuronidase (GUS) reporter (pNbBeclin::GUS). NbBeclin 1 promoter activity was significantly enhanced in NbCMT3/3-2-silenced plants. Thus, NbCMT3/3-2 silencing had pleiotropic effects on development by interfering with NbBeclin 1 expression and autophagy-related processes.
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Affiliation(s)
- Wen-Jing You
- Department of Biology, National Changhua University of Education, No.1, Jin-De Road, Changhua, Taiwan
| | - Yun-Ru Feng
- Department of Biology, National Changhua University of Education, No.1, Jin-De Road, Changhua, Taiwan
| | - Ya-Han Shen
- Department of Biology, National Changhua University of Education, No.1, Jin-De Road, Changhua, Taiwan
| | - Yi-Ru Chen
- Department of Biology, National Changhua University of Education, No.1, Jin-De Road, Changhua, Taiwan
| | - Tzy-Yi Chen
- Department of Biology, National Changhua University of Education, No.1, Jin-De Road, Changhua, Taiwan
| | - Shih-Feng Fu
- Department of Biology, National Changhua University of Education, No.1, Jin-De Road, Changhua, Taiwan
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37
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Kim J. Sugar metabolism as input signals and fuel for leaf senescence. Genes Genomics 2019; 41:737-746. [PMID: 30879182 DOI: 10.1007/s13258-019-00804-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 02/21/2019] [Indexed: 12/27/2022]
Abstract
Senescence in plants is an active and acquired developmental process that occurs at the last developmental stage during the life cycle of a plant. Leaf senescence is a relatively slow process, which is characterized by loss of photosynthetic activity and breakdown of macromolecules, to compensate for reduced energy production. Sugars, major photosynthetic assimilates, are key substrates required for cellular respiration to produce intermediate sources of energy and reducing power, which are known to be essential for the maintenance of cellular processes during senescence. In addition, sugars play roles as signaling molecules to facilitate a wide range of developmental processes as metabolic sensors. However, the roles of sugar during the entire period of senescence remain fragmentary. The purpose of the present review was to examine and explore changes in production, sources, and functions of sugars during leaf senescence. Further, the review explores the current state of knowledge on how sugars mediate the onset or progression of leaf senescence. Progress in the area would facilitate the determination of more sophisticated ways of manipulating the senescence process in plants and offer insights that guide efforts to maintain nutrients in leafy plants during postharvest storage.
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Affiliation(s)
- Jeongsik Kim
- Faculty of Science Education, Jeju National University, Jeju, 63243, Republic of Korea.
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Azoulay‐Shemer T, Schwankl N, Rog I, Moshelion M, Schroeder JI. Starch biosynthesis by
AGP
ase, but not starch degradation by
BAM
1/3 and
SEX
1, is rate‐limiting for
CO
2
‐regulated stomatal movements under short‐day conditions. FEBS Lett 2018; 592:2739-2759. [DOI: 10.1002/1873-3468.13198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 01/27/2023]
Affiliation(s)
- Tamar Azoulay‐Shemer
- Division of Biological Sciences, Cell and Developmental Biology Section University of California San Diego La Jolla CA USA
| | - Nikki Schwankl
- Division of Biological Sciences, Cell and Developmental Biology Section University of California San Diego La Jolla CA USA
| | - Ido Rog
- Department of Plant & Environmental Sciences Weizmann Institute of Science Rehovot Israel
| | - Menachem Moshelion
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture The Robert H. Smith Faculty of Agriculture, Food and Environment The Hebrew University of Jerusalem Rehovot Israel
| | - Julian I. Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section University of California San Diego La Jolla CA USA
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39
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Otegui MS. Vacuolar degradation of chloroplast components: autophagy and beyond. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:741-750. [PMID: 28992297 DOI: 10.1093/jxb/erx234] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/10/2017] [Indexed: 05/21/2023]
Abstract
Chloroplast degradation during natural or stress-induced senescence requires the participation of both plastidic and extraplastidic degradative pathways. As part of the extraplastidic pathways, chloroplasts export stroma, envelope, and thylakoid proteins in membrane-bound organelles that are ultimately degraded in vacuoles. Some of these pathways, such as the formation of senescence-associated vacuoles (SAVs) and CV-containing vesicles (CCVs), do not depend on autophagy, whereas delivery of Rubisco-containing bodies (RCBs), ATI1-PS (ATG8-interacting Protein 1) bodies, and small starch-like granule (SSLG) bodies is autophagy dependent. In addition, autophagy of entire chloroplasts delivers damaged chloroplasts into the vacuolar lumen for degradation. This review summarizes the autophagy-dependent and independent trafficking mechanisms by which plant cells degrade chloroplast components in vacuoles.
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Affiliation(s)
- Marisa S Otegui
- Laboratory of Cell and Molecular Biology and Departments of Botany and Genetics, University of Wisconsin-Madison, WI, USA
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40
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Findinier J, Tunçay H, Schulz-Raffelt M, Deschamps P, Spriet C, Lacroix JM, Duchêne T, Szydlowski N, Li-Beisson Y, Peltier G, D'Hulst C, Wattebled F, Dauvillée D. The Chlamydomonas mex1 mutant shows impaired starch mobilization without maltose accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5177-5189. [PMID: 29040651 DOI: 10.1093/jxb/erx343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The MEX1 locus of Chlamydomonas reinhardtii was identified in a genetic screen as a factor that affects starch metabolism. Mutation of MEX1 causes a slow-down in the mobilization of storage polysaccharide. Cosegregation and functional complementation analyses were used to assess the involvement of the Mex1 protein in starch degradation. Heterologous expression experiments performed in Escherichia coli and Arabidopsis thaliana allowed us to test the capacity of the algal protein in maltose export. In contrast to the A. thaliana mex1 mutant, the mutation in C. reinhardtii does not lead to maltose accumulation and growth impairment. Although localized in the plastid envelope, the algal protein does not transport maltose efficiently across the envelope, but partly complements the higher plant mutant. Both Mex orthologs restore the growth of the E. coli ptsG mutant strain on glucose-containing medium, revealing the capacity of these proteins to transport this hexose. These findings suggest that Mex1 is essential for starch mobilization in both Chlamydomonas and Arabidopsis, and that this protein family may support several functions and not only be restricted to maltose export across the plastidial envelope.
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Affiliation(s)
- Justin Findinier
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Hande Tunçay
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Miriam Schulz-Raffelt
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Philippe Deschamps
- Université Paris-Sud 11, CNRS UMR 8079 Unité d'Ecologie, Systématique et Evolution, 91400 Orsay, France
| | - Corentin Spriet
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Jean-Marie Lacroix
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Thierry Duchêne
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Nicolas Szydlowski
- Université de Lille, CNRS, USR 3290-MSAP-Miniaturisation pour la Synthèse l'Analyse et la Protéomique, 59000 Lille, France
| | - Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Christophe D'Hulst
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Fabrice Wattebled
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - David Dauvillée
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
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41
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Majsec K, Bhuiyan NH, Sun Q, Kumari S, Kumar V, Ware D, van Wijk KJ. The Plastid and Mitochondrial Peptidase Network in Arabidopsis thaliana: A Foundation for Testing Genetic Interactions and Functions in Organellar Proteostasis. THE PLANT CELL 2017; 29:2687-2710. [PMID: 28947489 PMCID: PMC5728138 DOI: 10.1105/tpc.17.00481] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/29/2017] [Accepted: 09/21/2017] [Indexed: 05/17/2023]
Abstract
Plant plastids and mitochondria have dynamic proteomes. Protein homeostasis in these organelles is maintained by a proteostasis network containing protein chaperones, peptidases, and their substrate recognition factors. However, many peptidases, as well as their functional connections and substrates, are poorly characterized. This review provides a systematic insight into the organellar peptidase network in Arabidopsis thaliana We present a compendium of known and putative Arabidopsis peptidases and inhibitors, and compare the distribution of plastid and mitochondrial peptidases to the total peptidase complement. This comparison shows striking biases, such as the (near) absence of cysteine and aspartic peptidases and peptidase inhibitors, whereas other peptidase families were exclusively organellar; reasons for such biases are discussed. A genome-wide mRNA-based coexpression data set was generated based on quality controlled and normalized public data, and used to infer additional plastid peptidases and to generate a coexpression network for 97 organellar peptidase baits (1742 genes, making 2544 edges). The graphical network includes 10 modules with specialized/enriched functions, such as mitochondrial protein maturation, thermotolerance, senescence, or enriched subcellular locations such as the thylakoid lumen or chloroplast envelope. The peptidase compendium, including the autophagy and proteosomal systems, and the annotation based on the MEROPS nomenclature of peptidase clans and families, is incorporated into the Plant Proteome Database.
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Affiliation(s)
- Kristina Majsec
- Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
| | - Nazmul H Bhuiyan
- School for Integrative Plant Sciences, Section Plant Biology, Cornell University, Ithaca, New York 14853
| | - Qi Sun
- Computational Biology Service Unit, Cornell University, Ithaca, New York 14853
| | - Sunita Kumari
- Cold Spring Harbor laboratory, Cold Spring Harbor, New York 17724
| | - Vivek Kumar
- Cold Spring Harbor laboratory, Cold Spring Harbor, New York 17724
| | - Doreen Ware
- Cold Spring Harbor laboratory, Cold Spring Harbor, New York 17724
| | - Klaas J van Wijk
- School for Integrative Plant Sciences, Section Plant Biology, Cornell University, Ithaca, New York 14853
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42
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Alpha-Glucan, Water Dikinase 1 Affects Starch Metabolism and Storage Root Growth in Cassava (Manihot esculenta Crantz). Sci Rep 2017; 7:9863. [PMID: 28852191 PMCID: PMC5575247 DOI: 10.1038/s41598-017-10594-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 08/10/2017] [Indexed: 11/20/2022] Open
Abstract
Regulation of storage root development by source strength remains largely unknown. The cassava storage root delay (srd) T-DNA mutant postpones storage root development but manifests normal foliage growth as wild-type plants. The SRD gene was identified as an orthologue of α-glucan, water dikinase 1 (GWD1), whose expression is regulated under conditions of light/dark cycles in leaves and is associated with storage root development. The GWD1-RNAi cassava plants showed both retarded plant and storage root growth, as a result of starch excess phenotypes with reduced photosynthetic capacity and decreased levels of soluble saccharides in their leaves. These leaves contained starch granules having greatly increased amylose content and type C semi-crystalline structures with increased short chains that suggested storage starch. In storage roots of GWD1-RNAi lines, maltose content was dramatically decreased and starches with much lower phosphorylation levels showed a drastically reduced β-amylolytic rate. These results suggested that GWD1 regulates transient starch morphogenesis and storage root growth by decreasing photo-assimilation partitioning from the source to the sink and by starch mobilization in root crops.
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43
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Malinova I, Alseekh S, Feil R, Fernie AR, Baumann O, Schöttler MA, Lunn JE, Fettke J. Starch Synthase 4 and Plastidal Phosphorylase Differentially Affect Starch Granule Number and Morphology. PLANT PHYSIOLOGY 2017; 174:73-85. [PMID: 28275148 PMCID: PMC5411139 DOI: 10.1104/pp.16.01859] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/06/2017] [Indexed: 05/03/2023]
Abstract
The process of starch granule formation in leaves of Arabidopsis (Arabidopsis thaliana) is obscure. Besides STARCH SYNTHASE4 (SS4), the PLASTIDIAL PHOSPHORYLASE (PHS1) also seems to be involved, since dpe2-1/phs1a double mutants lacking both PHS1 and the cytosolic DISPROPORTIONATING ENZYME2 (DPE2) displayed only one starch granule per chloroplast under normal growth conditions. For further studies, a dpe2-1/phs1a/ss4 triple mutant and various combinations of double mutants were generated and metabolically analyzed with a focus on starch metabolism. The dpe2-1/phs1a/ss4 mutant revealed a massive starch excess phenotype. Furthermore, these plants grown under 12 h of light/12 h of dark harbored a single large and spherical starch granule per plastid. The number of starch granules was constant when the light/dark regime was altered, but this was not observed in the parental lines. With regard to growth, photosynthetic parameters, and metabolic analyses, the triple mutant additionally displayed alterations in comparison with ss4 and dpe2-1/phs1a The results clearly illustrate that PHS1 and SS4 are differently involved in starch granule formation and do not act in series. However, SS4 appears to exert a stronger influence. In connection with the characterized double mutants, we discuss the generation of starch granules and the observed formation of spherical starch granules.
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Affiliation(s)
- Irina Malinova
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
| | - Saleh Alseekh
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
| | - Regina Feil
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
| | - Alisdair R Fernie
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
| | - Otto Baumann
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
| | - Mark Aurel Schöttler
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
| | - John E Lunn
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
| | - Joerg Fettke
- Biopolymer Analytics (I.M., J.F.) and Zoophysiology (O.B.), Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany; and
- Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany (S.A., R.F., A.R.F., M.A.S., J.E.L.)
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44
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Li J, Zhou W, Francisco P, Wong R, Zhang D, Smith SM. Inhibition of Arabidopsis chloroplast β-amylase BAM3 by maltotriose suggests a mechanism for the control of transitory leaf starch mobilisation. PLoS One 2017; 12:e0172504. [PMID: 28225829 PMCID: PMC5321445 DOI: 10.1371/journal.pone.0172504] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/06/2017] [Indexed: 01/31/2023] Open
Abstract
Starch breakdown in leaves at night is tightly matched to the duration of the dark period, but the mechanism by which this regulation is achieved is unknown. In Arabidopsis chloroplasts, β-amylase BAM3 hydrolyses transitory starch, producing maltose and residual maltotriose. The aim of the current research was to investigate the regulatory and kinetic properties of BAM3. The BAM3 protein was expressed in Escherichia coli and first assayed using a model substrate. Enzyme activity was stimulated by treatment with dithiothreitol and was increased 40% by 2–10 μM Ca2+ but did not require Mg2+. In order to investigate substrate specificity and possible regulatory effects of glucans, we developed a GC-MS method to assay reaction products. BAM3 readily hydrolysed maltohexaose with a Km of 1.7 mM and Kcat of 4300 s-1 but activity was 3.4-fold lower with maltopentaose and was negligible with maltotetraose. With maltohexaose or amylopectin as substrates and using [UL-13C12]maltose in an isotopic dilution method, we discovered that BAM3 activity is inhibited by maltotriose at physiological (mM) concentrations, but not by maltose. In contrast, the extracellular β-amylase of barley is only weakly inhibited by maltotriose. Our results may explain the impaired starch breakdown in maltotriose-accumulating mutants such as dpe1 which lacks the chloroplast disproportionating enzyme (DPE1) metabolising maltotriose to glucose. We hypothesise that the rate of starch breakdown in leaves can be regulated by inhibition of BAM3 by maltotriose, the concentration of which is determined by DPE, which is in turn influenced by the stromal concentration of glucose. Since the plastid glucose transporter pGlcT catalyses facilitated diffusion between stroma and cytosol, changes in consumption of glucose in the cytosol are expected to lead to concomitant changes in plastid glucose and maltotriose, and hence compensatory changes in BAM3 activity.
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Affiliation(s)
- Jing Li
- School of Plant Biology, The University of Western Australia, Western Australia, Australia
| | - Wenxu Zhou
- Centre for Energy, Faculty of Engineering, Computing and Mathematics, The University of Western Australia, Western Australia, Australia
| | - Perigio Francisco
- School of Plant Biology, The University of Western Australia, Western Australia, Australia
| | - Russell Wong
- School of Plant Biology, The University of Western Australia, Western Australia, Australia
| | - Dongke Zhang
- Centre for Energy, Faculty of Engineering, Computing and Mathematics, The University of Western Australia, Western Australia, Australia
| | - Steven M. Smith
- School of Biological Sciences, University of Tasmania, Tasmania, Australia
- * E-mail:
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45
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Baslam M, Baroja-Fernández E, Ricarte-Bermejo A, Sánchez-López ÁM, Aranjuelo I, Bahaji A, Muñoz FJ, Almagro G, Pujol P, Galarza R, Teixidor P, Pozueta-Romero J. Genetic and isotope ratio mass spectrometric evidence for the occurrence of starch degradation and cycling in illuminated Arabidopsis leaves. PLoS One 2017; 12:e0171245. [PMID: 28152100 PMCID: PMC5289593 DOI: 10.1371/journal.pone.0171245] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/17/2017] [Indexed: 11/20/2022] Open
Abstract
Although there is a great wealth of data supporting the occurrence of simultaneous synthesis and breakdown of storage carbohydrate in many organisms, previous 13CO2 pulse-chase based studies indicated that starch degradation does not operate in illuminated Arabidopsis leaves. Here we show that leaves of gwd, sex4, bam4, bam1/bam3 and amy3/isa3/lda starch breakdown mutants accumulate higher levels of starch than wild type (WT) leaves when cultured under continuous light (CL) conditions. We also show that leaves of CL grown dpe1 plants impaired in the plastidic disproportionating enzyme accumulate higher levels of maltotriose than WT leaves, the overall data providing evidence for the occurrence of extensive starch degradation in illuminated leaves. Moreover, we show that leaves of CL grown mex1/pglct plants impaired in the chloroplastic maltose and glucose transporters display a severe dwarf phenotype and accumulate high levels of maltose, strongly indicating that the MEX1 and pGlcT transporters are involved in the export of starch breakdown products to the cytosol to support growth during illumination. To investigate whether starch breakdown products can be recycled back to starch during illumination through a mechanism involving ADP-glucose pyrophosphorylase (AGP) we conducted kinetic analyses of the stable isotope carbon composition (δ13C) in starch of leaves of 13CO2 pulsed-chased WT and AGP lacking aps1 plants. Notably, the rate of increase of δ13C in starch of aps1 leaves during the pulse was exceedingly higher than that of WT leaves. Furthermore, δ13C decline in starch of aps1 leaves during the chase was much faster than that of WT leaves, which provides strong evidence for the occurrence of AGP-mediated cycling of starch breakdown products in illuminated Arabidopsis leaves.
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Affiliation(s)
- Marouane Baslam
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Edurne Baroja-Fernández
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Adriana Ricarte-Bermejo
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Ángela María Sánchez-López
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Iker Aranjuelo
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Abdellatif Bahaji
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Francisco José Muñoz
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Goizeder Almagro
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Pablo Pujol
- Servicio de Apoyo a la Investigación, Universidad Pública de Navarra, Campus de Arrosadia, Iruña, Nafarroa, Spain
| | - Regina Galarza
- Servicio de Apoyo a la Investigación, Universidad Pública de Navarra, Campus de Arrosadia, Iruña, Nafarroa, Spain
| | - Pilar Teixidor
- Centres Científics i Tecnològics, Universitat de Barcelona, C/ Lluís Solé I Sabarís 1–3, Barcelona, Spain
| | - Javier Pozueta-Romero
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
- * E-mail:
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46
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Wang Y, Zheng X, Yu B, Han S, Guo J, Tang H, Yu AYL, Deng H, Hong Y, Liu Y. Disruption of microtubules in plants suppresses macroautophagy and triggers starch excess-associated chloroplast autophagy. Autophagy 2016; 11:2259-74. [PMID: 26566764 PMCID: PMC4835195 DOI: 10.1080/15548627.2015.1113365] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Microtubules, the major components of cytoskeleton, are involved in various fundamental biological processes in plants. Recent studies in mammalian cells have revealed the importance of microtubule cytoskeleton in autophagy. However, little is known about the roles of microtubules in plant autophagy. Here, we found that ATG6 interacts with TUB8/β-tubulin 8 and colocalizes with microtubules in Nicotiana benthamiana. Disruption of microtubules by either silencing of tubulin genes or treatment with microtubule-depolymerizing agents in N. benthamiana reduces autophagosome formation during upregulation of nocturnal or oxidation-induced macroautophagy. Furthermore, a blockage of leaf starch degradation occurred in microtubule-disrupted cells and triggered a distinct ATG6-, ATG5- and ATG7-independent autophagic pathway termed starch excess-associated chloroplast autophagy (SEX chlorophagy) for clearance of dysfunctional chloroplasts. Our findings reveal that an intact microtubule network is important for efficient macroautophagy and leaf starch degradation.
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Affiliation(s)
- Yan Wang
- a Center for Plant Biology ; Beijing , China.,b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
| | - Xiyin Zheng
- a Center for Plant Biology ; Beijing , China.,b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
| | - Bingjie Yu
- a Center for Plant Biology ; Beijing , China.,b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
| | - Shaojie Han
- a Center for Plant Biology ; Beijing , China.,b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
| | - Jiangbo Guo
- a Center for Plant Biology ; Beijing , China
| | - Haiping Tang
- b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
| | - Alice Yunzi L Yu
- b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
| | - Haiteng Deng
- b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
| | - Yiguo Hong
- c Research Center for Plant RNA Signaling; College of Life and Environmental Sciences; Hangzhou Normal University ; Hangzhou , China
| | - Yule Liu
- a Center for Plant Biology ; Beijing , China.,b MOE Key Laboratory of Bioinformatics; School of Life Sciences; Tsinghua University ; Beijing , China
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Ghaffari MR, Shahinnia F, Usadel B, Junker B, Schreiber F, Sreenivasulu N, Hajirezaei MR. The Metabolic Signature of Biomass Formation in Barley. PLANT & CELL PHYSIOLOGY 2016; 57:1943-60. [PMID: 27388338 DOI: 10.1093/pcp/pcw117] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 06/16/2016] [Indexed: 05/18/2023]
Abstract
The network analysis of genome-wide transcriptome responses, metabolic signatures and enzymes' relationship to biomass formation has been studied in a diverse panel of 12 barley accessions during vegetative and reproductive stages. The primary metabolites and enzymes involved in central metabolism that determine the accumulation of shoot biomass at the vegetative stage of barley development are primarily being linked to sucrose accumulation and sucrose synthase activity. Interestingly, the metabolic and enzyme links which are strongly associated with biomass accumulation during reproductive stages are related to starch accumulation and tricarboxylic acid (TCA) cycle intermediates citrate, malate, trans-aconitate and isocitrate. Additional significant associations were also found for UDP glucose, ATP and the amino acids isoleucine, valine, glutamate and histidine during the reproductive stage. A network analysis resulted in a combined identification of metabolite and enzyme signatures indicative for grain weight accumulation that was correlated with the activity of ADP-glucose pyrophosphorylase (AGPase), a rate-limiting enzyme involved in starch biosynthesis, and with that of alanine amino transferase involved in the synthesis of storage proteins. We propose that the mechanism related to vegetative and reproductive biomass formation vs. seed biomass formation is being linked to distinct fluxes regulating sucrose, starch, sugars and amino acids as central resources. These distinct biomarkers can be used to engineer biomass production and grain weight in barley.
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Affiliation(s)
- Mohammad R Ghaffari
- Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREO), Tehran, Iran Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstraße 3, D-06466 Gatersleben, Germany
| | - Fahimeh Shahinnia
- Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstraße 3, D-06466 Gatersleben, Germany
| | - Björn Usadel
- Institute of Botany, RWTH Aachen University, BioSC Germany and IBG-2 Plant Sciences, Forschungszentrum Jülich, D-52428 Jülich, Germany
| | - Björn Junker
- Institute of Pharmacy/Biosynthesis of Active Substances, Hoher Weg 8, Halle (Saale), Germany
| | - Falk Schreiber
- Monash University, Clayton Campus, Wellington Road, Clayton, VIC 3800, Australia
| | - Nese Sreenivasulu
- International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
| | - Mohammad R Hajirezaei
- Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstraße 3, D-06466 Gatersleben, Germany
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48
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Wang Y, Zheng X, Liu Y. Functional links between microtubules, autophagy and leaf starch degradation in plants. PLANT SIGNALING & BEHAVIOR 2016; 11:e1201626. [PMID: 27322929 PMCID: PMC4991325 DOI: 10.1080/15592324.2016.1201626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/08/2016] [Accepted: 06/09/2016] [Indexed: 05/28/2023]
Abstract
Mounting evidence suggests that microtubules play important roles in several aspects of autophagy in mammalian cells, such as autophagosome biogenesis, autophagosome trafficking and autolysosome formation. However, little research attention has been paid to the engagement of microtubules in plant autophagy. Recently, we reported novel findings in Nicotiana benthamiana that disruption of microtubules reduces autophagosome formation during upregulation of macroautophagy and triggers a specific type of chloroplast autophagy (SEX chlorophagy), which is closely associated with the starch-excess phenotype of leaves. These findings reveal important functional links between microtubules, autophagy and leaf starch degradation in plants.
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Affiliation(s)
- Yan Wang
- Center for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiyin Zheng
- Center for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yule Liu
- Center for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China
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49
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Kmiecik P, Leonardelli M, Teige M. Novel connections in plant organellar signalling link different stress responses and signalling pathways. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3793-807. [PMID: 27053718 DOI: 10.1093/jxb/erw136] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To coordinate growth, development and responses to environmental stimuli, plant cells need to communicate the metabolic state between different sub-compartments of the cell. This requires signalling pathways, including protein kinases, secondary messengers such as Ca(2+) ions or reactive oxygen species (ROS) as well as metabolites and plant hormones. The signalling networks involved have been intensively studied over recent decades and have been elaborated more or less in detail. However, it has become evident that these signalling networks are also tightly interconnected and often merge at common targets such as a distinct group of transcription factors, most prominently ABI4, which are amenable to regulation by phosphorylation, potentially also in a Ca(2+)- or ROS-dependent fashion. Moreover, the signalling pathways connect several organelles or subcellular compartments, not only in functional but also in physical terms, linking for example chloroplasts to the nucleus or peroxisomes to chloroplasts thereby enabling physical routes for signalling by metabolite exchange or even protein translocation. Here we briefly discuss these novel findings and try to connect them in order to point out the remaining questions and emerging developments in plant organellar signalling.
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Affiliation(s)
- Przemyslaw Kmiecik
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Manuela Leonardelli
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Markus Teige
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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50
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Jones DC, Zheng W, Huang S, Du C, Zhao X, Yennamalli RM, Sen TZ, Nettleton D, Wurtele ES, Li L. A Clade-Specific Arabidopsis Gene Connects Primary Metabolism and Senescence. FRONTIERS IN PLANT SCIENCE 2016; 7:983. [PMID: 27462324 PMCID: PMC4940393 DOI: 10.3389/fpls.2016.00983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/21/2016] [Indexed: 05/05/2023]
Abstract
Nearly immobile, plants have evolved new components to be able to respond to changing environments. One example is Qua Quine Starch (QQS, AT3G30720), an Arabidopsis thaliana-specific orphan gene that integrates primary metabolism with adaptation to environment changes. SAQR (Senescence-Associated and QQS-Related, AT1G64360), is unique to a clade within the family Brassicaceae; as such, the gene may have arisen about 20 million years ago. SAQR is up-regulated in QQS RNAi mutant and in the apx1 mutant under light-induced oxidative stress. SAQR plays a role in carbon allocation: overexpression lines of SAQR have significantly decreased starch content; conversely, in a saqr T-DNA knockout (KO) line, starch accumulation is increased. Meta-analysis of public microarray data indicates that SAQR expression is correlated with expression of a subset of genes involved in senescence, defense, and stress responses. SAQR promoter::GUS expression analysis reveals that SAQR expression increases after leaf expansion and photosynthetic capacity have peaked, just prior to visible natural senescence. SAQR is expressed predominantly within leaf and cotyledon vasculature, increasing in intensity as natural senescence continues, and then decreasing prior to death. In contrast, under experimentally induced senescence, SAQR expression increases in vasculature of cotyledons but not in true leaves. In SAQR KO line, the transcript level of the dirigent-like disease resistance gene (AT1G22900) is increased, while that of the Early Light Induced Protein 1 gene (ELIP1, AT3G22840) is decreased. Taken together, these data indicate that SAQR may function in the QQS network, playing a role in integration of primary metabolism with adaptation to internal and environmental changes, specifically those that affect the process of senescence.
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Affiliation(s)
- Dallas C. Jones
- Department of Genetics, Development and Cell Biology, Iowa State University, AmesIA, USA
| | - Wenguang Zheng
- Department of Genetics, Development and Cell Biology, Iowa State University, AmesIA, USA
| | - Sheng Huang
- Department of Genetics, Development and Cell Biology, Iowa State University, AmesIA, USA
| | - Chuanlong Du
- Department of Statistics, Iowa State University, AmesIA, USA
| | - Xuefeng Zhao
- Laurence H. Baker Center for Bioinformatics and Biological Statistics, Iowa State University, AmesIA, USA
| | - Ragothaman M. Yennamalli
- Department of Genetics, Development and Cell Biology, Iowa State University, AmesIA, USA
- Corn Insects and Crop Genetics Research Unit, United States Department of Agriculture-Agriculture Research Service, AmesIA, USA
| | - Taner Z. Sen
- Department of Genetics, Development and Cell Biology, Iowa State University, AmesIA, USA
- Corn Insects and Crop Genetics Research Unit, United States Department of Agriculture-Agriculture Research Service, AmesIA, USA
| | - Dan Nettleton
- Department of Statistics, Iowa State University, AmesIA, USA
| | - Eve S. Wurtele
- Department of Genetics, Development and Cell Biology, Iowa State University, AmesIA, USA
- Center for Metabolic Biology, Iowa State University, AmesIA, USA
| | - Ling Li
- Department of Genetics, Development and Cell Biology, Iowa State University, AmesIA, USA
- Center for Metabolic Biology, Iowa State University, AmesIA, USA
- *Correspondence: Ling Li,
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