Article
Multidisciplinary Sciences
Barney A. Geddes, Jason V. S. Kearsley, Jiarui Huang, Maryam Zamani, Zahed Muhammed, Leah Sather, Aakanx K. Panchal, George C. diCenzo, Turlough M. Finan
Summary: The symbiosis between leguminous plants and rhizobia in root nodules plays a key role in sustainable agricultural systems. Research has identified a minimal bacterial gene complement necessary for successful symbiosis and nitrogen fixation, paving the way for engineering symbiosis in nonlegume crops. By reorganizing the minimal symbiotic genes into three modules, researchers have provided a platform for expanding symbiosis to other plant partners and identifying genetic components that modulate competitiveness for nodulation and the effectiveness of rhizobia-plant symbioses.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Plant Sciences
Mingkee Achom, Proyash Roy, Beatriz Lagunas, Emma Picot, Luke Richards, Roxanna Bonyadi-Pour, Alonso J. Pardal, Laura Baxter, Bethany L. Richmond, Nadine Aschauer, Eleanor M. Fletcher, Monique Rowson, Joseph Blackwell, Charlotte Rich-Griffin, Kirankumar S. Mysore, Jiangqi Wen, Sascha Ott, Isabelle A. Carre, Miriam L. Gifford
Summary: A nodule circadian clock coordinates metabolic and regulatory activity during symbiosis by involving the gene Late Elongated Hypocotyl and rhythmic expression of nodule-specific cysteine-rich peptides. The rhythmic expression of these peptides may play a vital role in temporal coordination between bacterial activity and the rhythms of the plant host.
JOURNAL OF EXPERIMENTAL BOTANY
(2022)
Article
Plant Sciences
Thomas B. Irving, Sanhita Chakraborty, Sergey Ivanov, Michael Schultze, Kirankumar S. Mysore, Maria J. Harrison, Jean-Michel Ane
Summary: This study characterized the symbiotic phenotypes of four Medicago truncatula mutants and identified two genes, RAM1 and KIN3, involved in mycorrhization. The results showed that RAM1 acts upstream of KIN3 and that KIN3 is involved in suppressing plant defenses and promoting root colonization. KIN3 also plays an essential role in the symbiotic response to soil nitrogen levels.
Article
Plant Sciences
Beatrix Horvath, Berivan Gungor, Monika Toth, Agota Domonkos, Ferhan Ayaydin, Farheen Saifi, Yuhui Chen, Janos Barnabas Biro, Mickael Bourge, Zoltan Szabo, Zoltan Toth, Rujin Chen, Peter Kalo
Summary: By characterizing and analyzing three ineffective nitrogen-fixing Medicago truncatula mutants, we discovered that Mtsym19 and Mtsym20 mutants have defects in the same peptide NCR-new35, and the lack of NCR343 is responsible for the ineffective symbiosis of NF-FN9363. We found that the expression of NCR-new35 is significantly lower and limited to the transition zone of the nodule compared with other crucial NCRs. The fluorescent protein-tagged versions of NCR343 and NCR-new35 localized to the symbiotic compartment.
Article
Plant Sciences
Gabriela Arregui, Pablo Hipolito, Beatriz Pallol, Victoria Lara-Dampier, Diego Garcia-Rodriguez, Higinio P. Varela, Parinaz Tavakoli Zaniani, Dimitrios Balomenos, Timothy Paape, Teodoro Coba de la Pena, M. Mercedes Lucas, Jose J. Pueyo
Summary: Mercury (Hg) is highly toxic to all living organisms. Research has shown that Hg-tolerant rhizobia have the potential to increase plant tolerance in heavily contaminated soils, and mercuric reductase activity may play a critical role in this tolerance mechanism.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Microbiology
Beatriz Lagunas, Luke Richards, Chrysi Sergaki, Jamie Burgess, Alonso Javier Pardal, Rana M. F. Hussain, Bethany L. Richmond, Laura Baxter, Proyash Roy, Anastasia Pakidi, Gina Stovold, Saul Vazquez, Sascha Ott, Patrick Schaefer, Miriam L. Gifford
Summary: This study investigates the symbiotic relationship between Medicago truncatula and different strains of Sinorhizobium meliloti or Sinorhizobium medicae in three different soil types. The results show that symbiosis has significant effects on soil, plants, and microbial composition, which are not simply proportional to soil nutrient abundance. The plant actively regulates its root community, including limiting the growth of low nitrogen efficiency rhizobial strains, leading to nodule senescence. Therefore, selecting appropriate inoculation partners is important for plant, soil type, and microbial community.
Article
Plant Sciences
Loredana Lopez, Giorgio Perrella, Ornella Calderini, Andrea Porceddu, Francesco Panara
Summary: Histone methylation and acetylation play important roles in the regulation of plant growth and development. However, the study of these processes in Leguminosae species is limited. This research analyzed HMG genes in Medicago truncatula and identified unique combinations of domains. The study also identified HMG loci that may be involved in nodule development and symbiotic nitrogen fixation.
Article
Plant Sciences
Raul Huertas, Ivone Torres-Jerez, Shaun J. Curtin, Wolf Scheible, Michael Udvardi
Summary: Three PHO2-like genes in Medicago truncatula were characterized for their potential roles in phosphorus and nitrogen metabolism balance and symbiotic nitrogen fixation. Among them, MtPHO2B may play a key role in the balance of phosphorus and nitrogen, while MtPHO2C has limited regulatory effects on phosphorus metabolism. Genetic analysis also revealed a connection between phosphorus allocation, plant growth, and symbiotic nitrogen fixation performance. In conclusion, MtPHO2 genes play important roles in both systemic and localized (nodules) phosphorus metabolism.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Plant Sciences
Yitong Shen, Yelin Ma, Dengyao Li, Mingming Kang, Yue Pei, Rui Zhang, Weiyu Tao, Shenxi Huang, Wenjie Song, Yuecheng Li, Wanqi Huang, Duanyang Wang, Yuhui Chen
Summary: Medicago truncatula has been chosen as a model legume species for gene functional studies. Fast Neutron (FN) mutagenesis has been used to generate a large mutant resource in M. truncatula, which has been utilized to screen for symbiotic nitrogen fixation deficiency mutants. Whole genome sequencing has been employed to identify a SNF defective mutant FN007, which has a large segment deletion on chromosome 3. These findings demonstrate the usefulness of whole genome sequencing in characterizing FN induced deletion mutants and advancing our understanding of symbiotic nitrogen fixation in legume plants.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Plant Sciences
Rosario Castro-Rodriguez, Viviana Escudero, Maria Reguera, Patricia Gil-Diez, Julia Quintana, Rosa Isabel Prieto, Rakesh K. Kumar, Ella Brear, Louis Grillet, Jiangqi Wen, Kirankumar S. Mysore, Elsbeth L. Walker, Penelope M. C. Smith, Juan Imperial, Manuel Gonzalez-Guerrero
Summary: Yellow Stripe-Like (YSL) proteins, including MtSYL7, play an essential role in transition metal homeostasis in nodules. MtSYL7 is involved in transporting short peptides and contributes to maintaining metal homeostasis in root nodules, impacting nitrogen fixation and plant growth. Mutants with decreased MtYSL7 expression accumulate more copper and iron in nodules due to increased expression of iron uptake and delivery genes in roots.
PLANT CELL AND ENVIRONMENT
(2021)
Article
Plant Sciences
Marie-Laure Martin, Marjorie Pervent, Ilana Lambert, Stefano Colella, Mathilde Tancelin, Dany Severac, Gilles Clement, Pascal Tillard, Florian Frugier, Marc Lepetit
Summary: In mature symbiotic root nodules, rhizobia fix atmospheric dinitrogen to provide ammonium for plant nitrogen demand. The symbiosis is adjusted to the plant's nitrogen demand through systemic N signaling, controlling nodule development. Nodule expansion is stimulated under N deficit, while nodule senescence is activated under N satiety. Drought has a negative impact on nodules. In this study, split-root systems were used to characterize the systemic responses of symbiotic plants to localized osmotic stress. The application of PEG inhibited the symbiotic dinitrogen fixation activity of locally treated nodules, leading to nitrogen limitation. The localized PEG treatment triggered systemic signaling, stimulating nodule development and enhancing sucrose allocation. Transcriptomic reprogramming associated with PEG and N deficit signaling shared many target transcripts. These findings suggest that systemic N signaling plays a role in the adaptation of symbiotic plants to local variations in their edaphic environment.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Plant Sciences
Rose Y. Zhang, Baxter Massey, Ulrike Mathesius, Victoria C. Clarke
Summary: Legumes are more responsive to elevated CO2 conditions due to symbiotic nitrogen fixation. AON mutants with increased nodulation show higher biomass under eCO2 conditions through increased photosynthetic investment.
Article
Microbiology
Laura Baxter, Proyash Roy, Emma Picot, Jess Watts, Alex Jones, Helen Wilkinson, Patrick Schaefer, Miriam Gifford, Beatriz Lagunas
Summary: The improved and complete genome sequence of Sinorhizobium (Ensifer) meliloti strain WSM1022, a microsymbiont of Medicago species, was generated using Illumina and Oxford nanopore sequencing technologies. Comparison with other rhizobial strains revealed significant genomic differences, with similarities observed between meliloti strains and high efficiency strains WSM1022 and WSM419. The high-quality rhizobial genome sequence will help unravel the features that make a rhizobial symbiont highly efficient for nitrogen fixation.
Article
Plant Sciences
Szilard Kovacs, Lili Fodor, Agota Domonkos, Ferhan Ayaydin, Krisztian Laczi, Gabor Rakhely, Peter Kalo
Summary: Legumes form an endosymbiotic relationship with nitrogen-fixing soil bacteria through signaling pathways and activation of host genes. Mutant alleles of NSP2 gene in this study exhibit different responses to bacterial infection and nodule formation, indicating the crucial role of NSP2 in symbiotic interactions and nodule development.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Multidisciplinary Sciences
Rafael E. Venado, Lucas E. Wange, Defeng Shen, Fabienne Pinnau, Tonni Grube Andersen, Wolfgang Enard, Macarena Marin
Summary: This study provides genetic evidence for the formation of the nodule oxygen diffusion barrier in legumes, which is crucial for nitrogen fixation in root nodules.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)