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Wang G, Mao J, Ji M, Wang W, Fu J. A comprehensive assessment of photosynthetic acclimation to shade in C4 grass (Cynodon dactylon (L.) Pers.). BMC PLANT BIOLOGY 2024; 24:591. [PMID: 38902617 PMCID: PMC11191358 DOI: 10.1186/s12870-024-05242-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 06/03/2024] [Indexed: 06/22/2024]
Abstract
BACKGROUND Light deficit in shaded environment critically impacts the growth and development of turf plants. Despite this fact, past research has predominantly concentrated on shade avoidance rather than shade tolerance. To address this, our study examined the photosynthetic adjustments of Bermudagrass when exposed to varying intensities of shade to gain an integrative understanding of the shade response of C4 turfgrass. RESULTS We observed alterations in photosynthetic pigment-proteins, electron transport and its associated carbon and nitrogen assimilation, along with ROS-scavenging enzyme activity in shaded conditions. Mild shade enriched Chl b and LHC transcripts, while severe shade promoted Chl a, carotenoids and photosynthetic electron transfer beyond QA- (ET0/RC, φE0, Ψ0). The study also highlighted differential effects of shade on leaf and root components. For example, Soluble sugar content varied between leaves and roots as shade diminished SPS, SUT1 but upregulated BAM. Furthermore, we observed that shading decreased the transcriptional level of genes involving in nitrogen assimilation (e.g. NR) and SOD, POD, CAT enzyme activities in leaves, even though it increased in roots. CONCLUSIONS As shade intensity increased, considerable changes were noted in light energy conversion and photosynthetic metabolism processes along the electron transport chain axis. Our study thus provides valuable theoretical groundwork for understanding how C4 grass acclimates to shade tolerance.
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Affiliation(s)
- Guangyang Wang
- Coastal Salinity Tolerant Grass Engineering and Technology Research Center, Ludong University, Yantai, 264025, Shandong, China
| | - Jinyan Mao
- College of Agriculture, Ludong University, Yantai, 264025, Shandong, China
| | - Mingxia Ji
- Coastal Salinity Tolerant Grass Engineering and Technology Research Center, Ludong University, Yantai, 264025, Shandong, China
| | - Wei Wang
- Coastal Salinity Tolerant Grass Engineering and Technology Research Center, Ludong University, Yantai, 264025, Shandong, China
| | - Jinmin Fu
- Coastal Salinity Tolerant Grass Engineering and Technology Research Center, Ludong University, Yantai, 264025, Shandong, China.
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Yidilisi K, Wang Y, Guo Z, Guo Y, Kang X, Li S, Zhang W, Chao N, Liu L. The Functional Characterization of MaGS2 and Its Role as a Negative Regulator of Ciboria shiraiana. PLANTS (BASEL, SWITZERLAND) 2024; 13:1660. [PMID: 38931091 PMCID: PMC11207669 DOI: 10.3390/plants13121660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/22/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024]
Abstract
Glutamine synthetase (GS) is a key enzyme involved in nitrogen metabolism. GS can be divided into cytosolic and plastidic subtypes and has been reported to respond to various biotic and abiotic stresses. However, little research has been reported on the function of GS in mulberry. In this study, the full length of MaGS2 was cloned, resulting in 1302 bp encoding 433 amino acid residues. MaGS2 carried the typical GS2 motifs and clustered with plastidic-subtype GSs in the phylogenetic analysis. MaGS2 localized in chloroplasts, demonstrating that MaGS2 is a plastidic GS. The expression profile showed that MaGS2 is highly expressed in sclerotiniose pathogen-infected fruit and sclerotiniose-resistant fruit, demonstrating that MaGS2 is associated with the response to sclerotiniose in mulberry. Furthermore, the overexpression of MaGS2 in tobacco decreased the resistance against Ciboria shiraiana, and the knockdown of MaGS2 in mulberry by VIGS increased the resistance against C. shiraiana, demonstrating the role of MaGS2 as a negative regulator of mulberry resistance to C. shiraiana infection.
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Affiliation(s)
- Keermula Yidilisi
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Yuqiong Wang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Zixuan Guo
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Yangyang Guo
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Xiaoru Kang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Shan Li
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Wenhao Zhang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Nan Chao
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Li Liu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
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Zhang XF, Li Z, Lin H, Cheng Y, Wang H, Jiang Z, Ji Z, Huang Z, Chen H, Wei T. A phytoplasma effector destabilizes chloroplastic glutamine synthetase inducing chlorotic leaves that attract leafhopper vectors. Proc Natl Acad Sci U S A 2024; 121:e2402911121. [PMID: 38776366 PMCID: PMC11145293 DOI: 10.1073/pnas.2402911121] [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: 02/18/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
Leaf yellowing is a well-known phenotype that attracts phloem-feeding insects. However, it remains unclear how insect-vectored plant pathogens induce host leaf yellowing to facilitate their own transmission by insect vectors. Here, we report that an effector protein secreted by rice orange leaf phytoplasma (ROLP) inhibits chlorophyll biosynthesis and induces leaf yellowing to attract leafhopper vectors, thereby presumably promoting pathogen transmission. This effector, designated secreted ROLP protein 1 (SRP1), first secreted into rice phloem by ROLP, was subsequently translocated to chloroplasts by interacting with the chloroplastic glutamine synthetase (GS2). The direct interaction between SRP1 and GS2 disrupts the decamer formation of the GS2 holoenzyme, attenuating its enzymatic activity, thereby suppressing the synthesis of chlorophyll precursors glutamate and glutamine. Transgenic expression of SRP1 in rice plants decreased GS2 activity and chlorophyll precursor accumulation, finally inducing leaf yellowing. This process is correlated with the previous evidence that the knockout of GS2 expression in rice plants causes a similar yellow chlorosis phenotype. Consistently, these yellowing leaves attracted higher numbers of leafhopper vectors, caused the vectors to probe more frequently, and presumably facilitate more efficient phytoplasma transmission. Together, these results uncover the mechanism used by phytoplasmas to manipulate the leaf color of infected plants for the purpose of enhancing attractiveness to insect vectors.
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Affiliation(s)
- Xiao-Feng Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Zhanpeng Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Hanbin Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Yu Cheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Huanqin Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Zhoumian Jiang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Zhenxi Ji
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Zhejun Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Hongyan Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
| | - Taiyun Wei
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian350002, China
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Moreira E, Ferreira J, Coimbra S, Melo P. The significance of the two cytosolic glutamine synthetase enzymes, GLN1;3 and GLN1;5, in the context of seed development and germination in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 210:108631. [PMID: 38657550 DOI: 10.1016/j.plaphy.2024.108631] [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: 11/30/2023] [Revised: 02/21/2024] [Accepted: 04/14/2024] [Indexed: 04/26/2024]
Abstract
Glutamine synthetase (GS), an initial enzyme in nitrogen (N) plant metabolism, exists as a group of isoenzymes found in both cytosolic (GS1) and plastids (GS2) and has gathered significant attention for enhancing N use efficiency and crop yield. This work focuses on the A. thaliana GLN1;3 and GLN1;5 genes, the two predicted most expressed genes in seeds, among the five isogenes encoding GS1 in this species. The expression patterns were studied using transgenic marker line plants and qPCR during seed development and germination. The observed patterns highlight distinct functions for the two genes and confirm GLN1;5 as the most highly expressed GS1 gene in seeds. The GLN1;5, expression, oriented towards hypocotyl and cotyledons, suggests a role in protein turnover during germination, while the radicle-oriented expression of GLN1;3 supports a function in early external N uptake. While the single mutants exhibited a normal phenotype, except for a decrease in seed parameters, the double gln1;3/gln1;5 mutant displayed a germination delay, substantial impairment in growth, nitrogen metabolism, and number and quality of the seeds, as well as a diminishing in flowering. Although seed and pollen-specific, GLN1;5 expression is upregulated in the meristems of the gln1;3 mutants, filling the lack of GLN1;3 and ensuring the normal functioning of the gln1;3 mutants. These findings validate earlier in silico data on the expression patterns of GLN1;3 and GL1;5 genes in seeds, explore their different functions, and underscore their essential role in plant growth, seed production, germination, and early stages of plant development.
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Affiliation(s)
- Emanuel Moreira
- Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal; INOV4Agro - GreenUPorto - Research Centre on Sustainable Agri-Food Production, Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal.
| | - João Ferreira
- Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal.
| | - Sílvia Coimbra
- Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal; LAQV/REQUIMTE, Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal.
| | - Paula Melo
- Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal; INOV4Agro - GreenUPorto - Research Centre on Sustainable Agri-Food Production, Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal.
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5
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Li X, Gu Y, Kayoumu M, Muhammad N, Wang X, Gui H, Luo T, Wang Q, Wumaierjiang X, Ruan S, Iqbal A, Zhang X, Song M, Dong Q. Systematic characterization of Gossypium GLN family genes reveals a potential function of GhGLN1.1a regulates nitrogen use efficiency in cotton. BMC PLANT BIOLOGY 2024; 24:313. [PMID: 38654158 PMCID: PMC11036627 DOI: 10.1186/s12870-024-04990-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 04/05/2024] [Indexed: 04/25/2024]
Abstract
The enzyme glutamine synthetase (GLN) is mainly responsible for the assimilation and reassimilation of nitrogen (N) in higher plants. Although the GLN gene has been identified in various plants, there is little information about the GLN family in cotton (Gossypium spp.). To elucidate the roles of GLN genes in cotton, we systematically investigated and characterized the GLN gene family across four cotton species (G. raimondii, G. arboreum, G. hirsutum, and G. barbadense). Our analysis encompassed analysis of members, gene structure, cis-element, intragenomic duplication, and exploration of collinear relationships. Gene duplication analysis indicated that segmental duplication was the primary driving force for the expansion of the GhGLN gene family. Transcriptomic and quantitative real-time reverse-transcription PCR (qRT-PCR) analyses indicated that the GhGLN1.1a gene is responsive to N induction treatment and several abiotic stresses. The results of virus-induced gene silencing revealed that the accumulation and N use efficiency (NUE) of cotton were affected by the inactivation of GhGLN1.1a. This study comprehensively analyzed the GhGLN genes in Gossypium spp., and provides a new perspective on the functional roles of GhGLN1.1a in regulating NUE in cotton.
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Affiliation(s)
- Xiaotong Li
- Zhengzhou Research Base, National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan, China
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Yunqi Gu
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Mirezhatijiang Kayoumu
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Noor Muhammad
- Zhengzhou Research Base, National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan, China
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Xiangru Wang
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Huiping Gui
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Tong Luo
- Western Agricultural Research Center of Chinese Academy of Agricultural Sciences, Changji, 831100, Xinjiang, China
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Qianqian Wang
- Western Agricultural Research Center of Chinese Academy of Agricultural Sciences, Changji, 831100, Xinjiang, China
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Xieraili Wumaierjiang
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Sijia Ruan
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Asif Iqbal
- Department of Agriculture, Hazara University, Khyber Pakhtunkhwa, Mansehra, 21120, Pakistan
| | - Xiling Zhang
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China
| | - Meizhen Song
- Zhengzhou Research Base, National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan, China.
- Western Agricultural Research Center of Chinese Academy of Agricultural Sciences, Changji, 831100, Xinjiang, China.
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China.
| | - Qiang Dong
- Western Agricultural Research Center of Chinese Academy of Agricultural Sciences, Changji, 831100, Xinjiang, China.
- National Engineering Research Center of Cotton Biology Breeding and Industrial Technology /Institute of Cotton Research of CAAS, Anyang, 455000, Henan, China.
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6
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Funck D, Sinn M, Forlani G, Hartig JS. Guanidine production by plant homoarginine-6-hydroxylases. eLife 2024; 12:RP91458. [PMID: 38619227 PMCID: PMC11018352 DOI: 10.7554/elife.91458] [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] [Indexed: 04/16/2024] Open
Abstract
Metabolism and biological functions of the nitrogen-rich compound guanidine have long been neglected. The discovery of four classes of guanidine-sensing riboswitches and two pathways for guanidine degradation in bacteria hint at widespread sources of unconjugated guanidine in nature. So far, only three enzymes from a narrow range of bacteria and fungi have been shown to produce guanidine, with the ethylene-forming enzyme (EFE) as the most prominent example. Here, we show that a related class of Fe2+- and 2-oxoglutarate-dependent dioxygenases (2-ODD-C23) highly conserved among plants and algae catalyze the hydroxylation of homoarginine at the C6-position. Spontaneous decay of 6-hydroxyhomoarginine yields guanidine and 2-aminoadipate-6-semialdehyde. The latter can be reduced to pipecolate by pyrroline-5-carboxylate reductase but more likely is oxidized to aminoadipate by aldehyde dehydrogenase ALDH7B in vivo. Arabidopsis has three 2-ODD-C23 isoforms, among which Din11 is unusual because it also accepted arginine as substrate, which was not the case for the other 2-ODD-C23 isoforms from Arabidopsis or other plants. In contrast to EFE, none of the three Arabidopsis enzymes produced ethylene. Guanidine contents were typically between 10 and 20 nmol*(g fresh weight)-1 in Arabidopsis but increased to 100 or 300 nmol*(g fresh weight)-1 after homoarginine feeding or treatment with Din11-inducing methyljasmonate, respectively. In 2-ODD-C23 triple mutants, the guanidine content was strongly reduced, whereas it increased in overexpression plants. We discuss the implications of the finding of widespread guanidine-producing enzymes in photosynthetic eukaryotes as a so far underestimated branch of the bio-geochemical nitrogen cycle and propose possible functions of natural guanidine production.
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Affiliation(s)
- Dietmar Funck
- Department of Chemistry, University of KonstanzKonstanzGermany
| | - Malte Sinn
- Department of Chemistry, University of KonstanzKonstanzGermany
| | - Giuseppe Forlani
- Department of Life Science and Biotechnology, University of FerraraFerraraItaly
| | - Jörg S Hartig
- Department of Chemistry, University of KonstanzKonstanzGermany
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Kobercová E, Melo P, Fischer L. Validating the role of glutamine synthetase GLN2 during photorespiration in Arabidopsis thaliana. PLANT PHYSIOLOGY 2023; 194:324-328. [PMID: 37787606 PMCID: PMC10756748 DOI: 10.1093/plphys/kiad521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/18/2023] [Accepted: 09/20/2023] [Indexed: 10/04/2023]
Affiliation(s)
- Eliška Kobercová
- Faculty of Science, Department of Experimental Plant Biology, Charles University, Viničná 5, Prague 2, 128 44, Czech Republic
| | - Paula Melo
- Faculty of Sciences, Department of Biology and GreenUPorto - Research Centre on Sustainable Agrifood Production, University of Porto, Rua do Campo Alegre s/n, Porto, 4169-007, Portugal
| | - Lukáš Fischer
- Faculty of Science, Department of Experimental Plant Biology, Charles University, Viničná 5, Prague 2, 128 44, Czech Republic
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Wang Y, Bai J, Wen L, Wang W, Zhang L, Liu Z, Liu H. Phytotoxicity of microplastics to the floating plant Spirodela polyrhiza (L.): Plant functional traits and metabolomics. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 322:121199. [PMID: 36738884 DOI: 10.1016/j.envpol.2023.121199] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/20/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Freshwater ecosystems are gradually becoming sinks for terrestrial microplastics (MPs), posing a potential ecological risk. Although the effects of MPs on plankton and aquatic animals in freshwater ecosystems have been given increasing attention, the toxicity of MPs to the metabolism of aquatic plants remains unclear. Here, the model aquatic plant Spirodela polyrhiza (L.) Schleid. (S. polyrhiza) was exposed to polyvinyl chloride (PVC; 0, 10, 100 and 1000 mg/L) MPs, and changes in the plant functional traits and physiological metabolism were monitored. The results showed that the high dose of PVC MPs decreased the adventitious root elongation ratio by 41.68% and leaf multiplication ratio by 61.03% of S. polyrhiza, and resulted in the decrease in anthocyanin and nitrogen contents to 63.45% and 84.21% of the control group, respectively. Moreover, the widely targeted metabolomics analysis results showed 37 differential metabolites in the low-dose treatment and 119 differential metabolites in the high-dose treatment. PVC MPs interfered with organic matter accumulation by affecting carbon metabolism, nitrogen metabolism, amino acid metabolism and lipid metabolism, and S. polyrhiza resists PVC MP stress by regulating the synthesis and metabolism of secondary metabolites. PVC MPs had concentration-related toxicological effects on plant functional traits, inhibited plant growth and reproduction, affected plant nutrient metabolism, and exhibited profound effects on the nitrogen fate of aquatic plant habitats. Overall, we systematically summarized the metabolic response mechanisms of aquatic plants to PVC MP stress, providing a new perspective for studying the effects of MPs on plant trait function and ecological risks.
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Affiliation(s)
- Yaqi Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
| | - Junhong Bai
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
| | - Lixiang Wen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
| | - Wei Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
| | - Ling Zhang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
| | - Zhe Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
| | - Haizhu Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, PR China.
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Valderrama-Martín JM, Ortigosa F, Aledo JC, Ávila C, Cánovas FM, Cañas RA. Pine has two glutamine synthetase paralogs, GS1b.1 and GS1b.2, exhibiting distinct biochemical properties. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 113:1330-1347. [PMID: 36658761 DOI: 10.1111/tpj.16113] [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: 11/02/2022] [Revised: 12/15/2022] [Accepted: 01/13/2023] [Indexed: 06/17/2023]
Abstract
The enzyme glutamine synthetase (EC 6.3.1.2) is mainly responsible for the incorporation of inorganic nitrogen into organic molecules in plants. In the present work, a pine (Pinus pinaster) GS1 (PpGS1b.2) gene was identified, showing a high sequence identity with the GS1b.1 gene previously characterized in conifers. Phylogenetic analysis revealed that the presence of PpGS1b.2 is restricted to the genera Pinus and Picea and is not found in other conifers. Gene expression data suggest a putative role of PpGS1b.2 in plant development, similar to other GS1b genes from angiosperms, suggesting evolutionary convergence. The characterization of GS1b.1 and GS1b.2 at the structural, physicochemical, and kinetic levels has shown differences even though they have high sequence homology. GS1b.2 had a lower optimum pH (6 vs. 6.5) and was less thermally stable than GS1b.1. GS1b.2 exhibited positive cooperativity for glutamate and substrate inhibition for ammonium. However, GS1b.1 exhibited substrate inhibition behavior for glutamate and ATP. Alterations in the kinetic characteristics produced by site-directed mutagenesis carried out in this work strongly suggest an implication of amino acids at positions 264 and 267 in the active center of pine GS1b.1 and GS1b.2 being involved in affinity toward ammonium. Therefore, the amino acid differences between GS1b.1 and GS1b.2 would support the functioning of both enzymes to meet distinct plant needs.
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Affiliation(s)
- José Miguel Valderrama-Martín
- Grupo de Biología Molecular y Biotecnología, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Campus Universitario de Teatinos, 29071, Málaga, Spain
- Integrative Molecular Biology Lab, Universidad de Málaga, Campus Universitario de Teatinos, 29071, Málaga, Spain
| | - Francisco Ortigosa
- Grupo de Biología Molecular y Biotecnología, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Campus Universitario de Teatinos, 29071, Málaga, Spain
| | - Juan Carlos Aledo
- Integrative Molecular Biology Lab, Universidad de Málaga, Campus Universitario de Teatinos, 29071, Málaga, Spain
| | - Concepción Ávila
- Grupo de Biología Molecular y Biotecnología, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Campus Universitario de Teatinos, 29071, Málaga, Spain
| | - Francisco M Cánovas
- Grupo de Biología Molecular y Biotecnología, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Campus Universitario de Teatinos, 29071, Málaga, Spain
| | - Rafael A Cañas
- Integrative Molecular Biology Lab, Universidad de Málaga, Campus Universitario de Teatinos, 29071, Málaga, Spain
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