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Chen P, Wei Q, Yao Y, Wei J, Qiu L, Zhang B, Liu H. Inoculation with Azorhizobium caulinodans ORS571 enhances plant growth and salt tolerance of switchgrass (Panicum virgatum L.) seedlings. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:35. [PMID: 36864528 PMCID: PMC9983177 DOI: 10.1186/s13068-023-02286-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/18/2023] [Indexed: 03/04/2023]
Abstract
BACKGROUND Switchgrass (Panicum virgatum L.) is an important biofuel crop that may contribute to replacing petroleum fuels. However, slow seedling growth and soil salinization affect the growth and development of switchgrass. An increasing number of studies have shown that beneficial microorganisms promote plant growth and increase tolerance to salinity stress. However, the feasibility of inoculating switchgrass with Azorhizobium caulinodans ORS571 to enhance the growth and salt tolerance of its seedlings is unclear. Our previous study showed that A. caulinodans ORS571 could colonize wheat (Triticum aestivum L.) and thereby promote its growth and development and regulate the gene expression levels of microRNAs (miRNAs). RESULTS In this study, we systematically studied the impact of A. caulinodans ORS571 on switchgrass growth and development and the response to salinity stress; we also studied the underlying mechanisms during these biological processes. Inoculation with A. caulinodans ORS571 significantly alleviated the effect of salt stress on seedling growth. Under normal conditions, A. caulinodans ORS571 significantly increased fresh plant weight, chlorophyll a content, protein content, and peroxidase (POD) activity in switchgrass seedlings. Under salt stress, the fresh weight, dry weight, shoot and root lengths, and chlorophyll contents were all significantly increased, and some of these parameters even recovered to normal levels after inoculation with A. caulinodans ORS571. Soluble sugar and protein contents and POD and superoxide dismutase (SOD) activities were also significantly increased, contrary to the results for proline. Additionally, A. caulinodans ORS571 may alleviate salt stress by regulating miRNAs. Twelve selected miRNAs were all upregulated to different degrees under salt stress in switchgrass seedlings. However, the levels of miR169, miR171, miR319, miR393, miR535, and miR854 were decreased significantly after inoculation with A. caulinodans ORS571 under salt stress, in contrast to the expression level of miR399. CONCLUSION This study revealed that A. caulinodans ORS571 increased the salt tolerance of switchgrass seedlings by increasing their water content, photosynthetic efficiency, osmotic pressure maintenance, and reactive oxygen species (ROS) scavenging abilities and regulating miRNA expression. This work provides a new, creative idea for improving the salt tolerance of switchgrass seedlings.
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Affiliation(s)
- Pengyang Chen
- grid.144022.10000 0004 1760 4150College of Life Sciences, Northwest A & F University, Yangling, 712100 Shaanxi China
| | - Qiannan Wei
- grid.144022.10000 0004 1760 4150College of Life Sciences, Northwest A & F University, Yangling, 712100 Shaanxi China
| | - Yifei Yao
- grid.144022.10000 0004 1760 4150College of Life Sciences, Northwest A & F University, Yangling, 712100 Shaanxi China
| | - Jiaqi Wei
- grid.144022.10000 0004 1760 4150College of Life Sciences, Northwest A & F University, Yangling, 712100 Shaanxi China
| | - Li Qiu
- grid.144022.10000 0004 1760 4150College of Veterinary Medicine, Northwest A & F University, Yangling, 712100 Shaanxi China
| | - Baohong Zhang
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA.
| | - Huawei Liu
- College of Life Sciences, Northwest A & F University, Yangling, 712100, Shaanxi, China.
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Jardim-Messeder D, Zamocky M, Sachetto-Martins G, Margis-Pinheiro M. Chloroplastic ascorbate peroxidases targeted to stroma or thylakoid membrane: The chicken or egg dilemma. FEBS Lett 2022; 596:2989-3004. [PMID: 35776057 DOI: 10.1002/1873-3468.14438] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/04/2022] [Accepted: 06/07/2022] [Indexed: 12/14/2022]
Abstract
Ascorbate peroxidases (APXs) are heme peroxidases that remove hydrogen peroxide in different subcellular compartments with concomitant ascorbate cycling. Here, we analysed and discussed phylogenetic and molecular features of the APX family. Ancient APX originated as a soluble stromal enzyme, and early during plant evolution, acquired both chloroplast-targeting and mitochondrion-targeting sequences and an alternative splicing mechanism whereby it could be expressed as a soluble or thylakoid membrane-bound enzyme. Later, independent duplication and neofunctionalization events in some angiosperm groups resulted in individual genes encoding stromal, thylakoidal and mitochondrial isoforms. These data reaffirm the complexity of plant antioxidant defenses that allow diverse plant species to acquire new means to adapt to changing environmental conditions.
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Affiliation(s)
- Douglas Jardim-Messeder
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Brazil.,Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Brazil
| | - Marcel Zamocky
- Laboratory of Phylogenomic Ecology, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia.,Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | | | - Márcia Margis-Pinheiro
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Behr M, Speeckaert N, Kurze E, Morel O, Prévost M, Mol A, Mahamadou Adamou N, Baragé M, Renaut J, Schwab W, El Jaziri M, Baucher M. Leaf necrosis resulting from downregulation of poplar glycosyltransferase UGT72A2. TREE PHYSIOLOGY 2022; 42:1084-1099. [PMID: 34865151 DOI: 10.1093/treephys/tpab161] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/29/2021] [Indexed: 06/13/2023]
Abstract
Reactive species (RS) causing oxidative stress are unavoidable by-products of various plant metabolic processes, such as photosynthesis, respiration or photorespiration. In leaves, flavonoids scavenge RS produced during photosynthesis and protect plant cells against deleterious oxidative damages. Their biosynthesis and accumulation are therefore under tight regulation at the cellular level. Glycosylation has emerged as an essential biochemical reaction in the homeostasis of various specialized metabolites such as flavonoids. This article provides a functional characterization of the Populus tremula x P. alba (poplar) UGT72A2 coding for a UDP-glycosyltransferase that is localized in the chloroplasts. Compared with the wild type, transgenic poplar lines with decreased expression of UGT72A2 are characterized by reduced growth and oxidative damages in leaves, as evidenced by necrosis, higher content of glutathione and lipid peroxidation products as well as diminished soluble peroxidase activity and NADPH to NADP+ ratio under standard growing conditions. They furthermore display lower pools of phenolics, anthocyanins and total flavonoids but higher proanthocyanidins content. Promoter analysis revealed the presence of cis-elements involved in photomorphogenesis, chloroplast biogenesis and flavonoid biosynthesis. The UGT72A2 is regulated by the poplar MYB119, a transcription factor known to regulate the flavonoid biosynthesis pathway. Phylogenetic analysis and molecular docking suggest that UGT72A2 could glycosylate flavonoids; however, the actual substrate(s) was not consistently evidenced with either in vitro assays nor analyses of glycosylated products in leaves of transgenic poplar overexpressing or downregulated for UGT72A2. This article provides elements highlighting the importance of flavonoid glycosylation regarding protection against oxidative stress in poplar leaves and raises new questions about the link between this biochemical reaction and regulation of the redox homeostasis system.
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Affiliation(s)
- Marc Behr
- Laboratory of Plant Biotechnology, Université libre de Bruxelles, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium
| | - Nathanael Speeckaert
- Laboratory of Plant Biotechnology, Université libre de Bruxelles, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium
| | - Elisabeth Kurze
- Biotechnology of Natural Products, Technische Universität München, 85354 Freising, Germany
| | - Oriane Morel
- Laboratory of Plant Biotechnology, Université libre de Bruxelles, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium
| | - Martine Prévost
- Unité de recherche Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, Bruxelles, Belgium
| | - Adeline Mol
- Laboratory of Plant Biotechnology, Université libre de Bruxelles, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium
| | - Nassirou Mahamadou Adamou
- Laboratory of Plant Biotechnology, Université libre de Bruxelles, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium
- Laboratoire de Biotechnologie Végétale et Amélioration des Plantes (LABAP), Université Abdou Moumouni de Niamey, Niamey, Niger
| | - Moussa Baragé
- Laboratoire de Biotechnologie Végétale et Amélioration des Plantes (LABAP), Université Abdou Moumouni de Niamey, Niamey, Niger
| | - Jenny Renaut
- Luxembourg Institute of Science and Technology, 4422 Belvaux, Luxembourg
| | - Wilfried Schwab
- Biotechnology of Natural Products, Technische Universität München, 85354 Freising, Germany
| | - Mondher El Jaziri
- Laboratory of Plant Biotechnology, Université libre de Bruxelles, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium
| | - Marie Baucher
- Laboratory of Plant Biotechnology, Université libre de Bruxelles, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium
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Do JH, Park SY, Park SH, Kim HM, Ma SH, Mai TD, Shim JS, Joung YH. Development of a Genome-Edited Tomato With High Ascorbate Content During Later Stage of Fruit Ripening Through Mutation of SlAPX4. FRONTIERS IN PLANT SCIENCE 2022; 13:836916. [PMID: 35498670 PMCID: PMC9039661 DOI: 10.3389/fpls.2022.836916] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/09/2022] [Indexed: 06/12/2023]
Abstract
Ascorbate is an essential antioxidant substance for humans. Due to the lack of ascorbate biosynthetic enzyme, a human must intake ascorbate from the food source. Tomato is one of the most widely consumed fruits, thus elevation of ascorbate content in tomato fruits will improve their nutritional value. Here we characterized Solanum lycopersicum ASCORBATE PEROXIDASE 4 (SlAPX4) as a gene specifically induced during fruit ripening. In tomatoes, ascorbate accumulates in the yellow stage of fruits, then decreases during later stages of fruit ripening. To investigate whether SlAPX is involved in the decrease of ascorbate, the expression of SlAPXs was analyzed during fruit maturation. Among nine SlAPXs, SlAPX4 is the only gene whose expression was induced during fruit ripening. Mutation of SlAPX4 by the CRISPR/Cas9 system increased ascorbate content in ripened tomato fruits, while ascorbate content in leaves was not significantly changed by mutation of SlAPX4. Phenotype analysis revealed that mutation of SlAPX4 did not induce an adverse effect on the growth of tomato plants. Collectively, we suggest that SlAPX4 mediates a decrease of ascorbate content during the later stage of fruit ripening, and mutation of SlAPX4 can be used for the development of genome-edited tomatoes with elevated ascorbate content in fruits.
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Chloroplast Thylakoidal Ascorbate Peroxidase, PtotAPX, Has Enhanced Resistance to Oxidative Stress in Populus tomentosa. Int J Mol Sci 2022; 23:ijms23063340. [PMID: 35328760 PMCID: PMC8953715 DOI: 10.3390/ijms23063340] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 02/04/2023] Open
Abstract
Chloroplasts are the most major producers of reactive oxygen species (ROS) during photosynthesis. However, the function of thylakoid ascorbate peroxidase (tAPX) in response to oxidative stress in wood trees is largely unknown. Our results showed that PtotAPX of Populus tomentosa could effectively utilize ascorbic acid (AsA) to hydrolyze hydrogen peroxide (H2O2) in vitro. The overexpression or antisense of PtotAPX (OX-PtotAPX or anti-PtotAPX, respectively) in Populus tomentosa plants did not significantly affect plant morphology during plant growth. When treated with methyl viologen (MV), the OX-PtotAPX plants exhibited less morphological damage under stress conditions compared to WT plants. OX-PtotAPX plants maintained lower H2O2 levels and malondialdehyde (MDA) contents, but more reduced AsA levels, a higher photosynthetic rate (Pn), and the maximal photochemical efficiency of PSII (Fv/Fm), whereas anti-PtotAPX plants showed the opposite phenotype. Furthermore, the activity of APX was slightly higher in OX-PtotAPX under normal growth conditions, and this activity significantly decreased after stress treatment, which was the lowest in anti-P. Based on these results, we propose that PtotAPX is important for protecting the photosynthetic machinery under severe oxidative stress conditions in P. tomentosa, and is a potential genetic resource for regulating the stress tolerance of woody plants.
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Zhang C, Zhang J, Liu Y, Liu X, Guo X, Li H, Liu D, Lu H. Integrated Transcriptomic and Proteomic Analysis in the Roadmap of the Xylem Development Stage in Populus tomentosa. FRONTIERS IN PLANT SCIENCE 2021; 12:724559. [PMID: 34804081 PMCID: PMC8600231 DOI: 10.3389/fpls.2021.724559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 10/04/2021] [Indexed: 06/13/2023]
Abstract
Xylem development plays an important role in the wood formation of plants. In this study, we found that xylem development was a rapid thickening process characterized by initially rapid increases in the number of tracheary elements and fiber cells and the thickness of the secondary walls that later plateaued. Transcriptome analysis showed that the xylan and lignin biosynthetic pathways, which are involved in the early rapid thickening of the xylem, were mainly upregulated in the second month. The expression of a total of 124 transcription factors (TFs), including 28 NAC TFs and 31 MYB TFs, peaked in 2- and 3-month-old plants compared with 1-month-old plants. Based on previous studies and the key cis-acting elements secondary wall NAC-binding elements, secondary wall MYB-responsive elements, W-box and TGTG[T/G/C], 10 TFs related to xylem development, 50 TFs with unknown function, 98 cell wall biosynthetic genes, and 47 programmed cell death (PCD) genes were used to construct a four-layer transcriptional regulatory network (TRN) with poplar NAC domain TFs to characterize the transcriptional regulation of cell wall biosynthesis and PCD in Populus tomentosa. The proteome revealed that post-transcriptional modification may be widely involved in lignification development. Overall, our results revealed that xylem development is a rapid thickening process in P. tomentosa, and expression patterns varied temporally from cell division to cell death.
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Affiliation(s)
- Chong Zhang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Jiaxue Zhang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Yadi Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Xiatong Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Xiaorui Guo
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Hui Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Di Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Hai Lu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
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