Insights in Plant Symbiotic Interactions: 2021

Editorial

10 February 2023

Editorial: Insights in plant symbiotic interactions: 2021

Andrea Genre

Katharina Pawlowski

Sabine Dagmar Zimmermann

and

Sergio Saia

1,476 views

1 citations

Editors

Sabine Dagmar Zimmermann

IPSiM Institute of Plant Science in Montpellier CNRS UMR5004

Sergio Saia

University of Pisa

Impact

(A) Generalized scheme of NCR gene structure. (B) Alignment of the top 5 most identical NCR peptides in P. sativum and M. truncatula (conservative sites are highlighted in blue, and conservative cysteines are highlighted in red).

Original Research

14 September 2022

A variable gene family encoding nodule-specific cysteine-rich peptides in pea (Pisum sativum L.)

Evgeny A. Zorin

, 12 more and

Vladimir A. Zhukov

4,298 views

13 citations

Schematic representation of ectomycorrhizal-based networks (A) across early ecological succession and (B) during sylvigenetic cycle. Dashed lines indicate plant–plant interactions through ECM CMNs. Blue arrows indicate nutrient transfers through ECM CMNs. (C) Summary of ECM network-related effects documented along the chronosequence.

Review

30 June 2022

Ectomycorrhizal Networks in the Anthropocene: From Natural Ecosystems to Urban Planning

Louise Authier

, 1 more and

Franck Richard

4,269 views

8 citations

Table comparing data on symbiotic genes involved in different nodulation steps in Arachis hypogaea, Aeschynomene evenia, Lotus japonicus, and Sesbania rostrata according to their symbionts. (A) Comparison of the presence (dark grey), absence (white), or unknown status (light grey) of symbiotic genes in the genome of A. hypogaea, A. evenia, L. japonicus, and S. rostrata. (B) Comparison of symbiotic genes that are induced (green), not induced (white) or of unknown status (grey) during nodulation in the four species. For L. japonicus this comparison includes the symbiont making intercellular infection (IRBG74) and intracellular infection (M. loti). (C) Comparison of the phenotypes with different genetic approaches (mutant or RNAi) in the four species and L. japonicus with the two symbionts. Red indicates absence of nodules (Nod-), orange indicates an intermediate strong phenotype (Nod+/−−), yellow indicates an intermediate weak phenotype (Nod+/−), and grey indicates the absence of data. For the Lotus-IRBG74 interaction, only transcriptome data of early time points is available (3, 5, and 10 dpi).

Mini Review

23 June 2022

Molecular Mechanisms of Intercellular Rhizobial Infection: Novel Findings of an Ancient Process

Johan Quilbé

, 2 more and

Jens Stougaard

6,055 views

29 citations

Original Research

11 May 2022

Biocontrol Potential of Endophytic Streptomyces malaysiensis 8ZJF-21 From Medicinal Plant Against Banana Fusarium Wilt Caused by Fusarium oxysporum f. sp. cubense Tropical Race 4

Lu Zhang

, 7 more and

Wei Wang

Banana (Musa spp.) is an important fruit crop cultivated in most tropical countries. Banana Fusarium wilt caused by Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) is the most destructive fungal disease. Biocontrol using endophytic microorganisms is considered as a safety and sustainable strategy. Actinomycetes have a potential for the production of diverse metabolites. Isolation of endophytic actinomycetes with high efficiency and broad-spectrum antagonism is key for exploring biocontrol agents. Our previous study showed that a total of 144 endophytic actinomycetes were isolated from different tissues of medicinal plants in Hainan, China. Especially, strain 8ZJF-21 exhibited a broad-spectrum antifungal activity. Its morphological, physiological, and biochemical characteristics were consistent with the genus Streptomyces. The phylogenetic tree demonstrated that strain 8ZJF-21 formed a distinct clade with Streptomyces malaysiensis. Average nucleotide identity (ANI) was 98.49% above the threshold of novel species. The pot experiment revealed that endophytic Streptomyces malaysiensis 8ZJF-21 could improve the plant resistance to Foc TR4 by enhancing the expression levels of defense-related and antioxidant enzyme genes. It also promoted the plant growth by producing several extracellular enzymes and metabolites. Antifungal mechanism assays showed that S. malaysiensis 8ZJF-21 extract inhibited mycelial growth and spore germination of Foc TR4 in vitro. Pathogenic cells occurred cytoplasmic heterogeneity, disappeared organelles, and ruptured ultrastructure. Sequencing and annotation of genome suggested that S. malaysiensis 8ZJF-21 had a potential of producing novel metabolites. Nineteen volatile organic compounds were obtained from the extract by Gas Chromatography-Mass Spectrometry (GC-MS). Hence, endophytic Streptomyces strains will become essential biocontrol agents of modern agricultural practice.

5,565 views

24 citations

Effect of water regime and soil microbial inoculation on the biomass allocation of Myrtus communis seedlings. For leaf biomass and root biomass there was a significant water regime × inoculation treatment interaction (Table 2), hence different lower-case letters indicate statistically significant differences across the 21 treatment combinations. For stem biomass, only the main effects of water regime and inoculation treatment were significant (Table 2), thus upper-case letters indicate a significant difference between different levels of drought stress and lower-case letters indicate a significant difference between different inoculation treatments within a water regime (Duncan’s new multiple range test, α = 0.05).

Original Research

27 May 2022

Soil Inoculation With Beneficial Microbes Buffers Negative Drought Effects on Biomass, Nutrients, and Water Relations of Common Myrtle

Soghra Azizi

, 4 more and

Martin K.-F. Bader

3,939 views

15 citations

Original sampling area (left) and importance of sampling areas indicated by CAM (right). CAM visualizes the importance for classifying images. The more red the pixel values are, the more important for classification, and the more blue, the less important. The magnification of the slide images was 40x. (A) Classified an image of class 1 correctly. (B) Misclassified an image of class 1 as class 0. (C) Misclassified an image of class 1 as class 2.

Methods

03 May 2022

TAIM: Tool for Analyzing Root Images to Calculate the Infection Rate of Arbuscular Mycorrhizal Fungi

Kaoru Muta

, 4 more and

Koichi Kise

4,342 views

4 citations

Quantitative analysis of tubulin microtubule organization in nitrogen-fixing cells of G. max (n = 21), G. soja (n = 56), P. vulgaris (n = 48), and L. japonicus (n = 31) nodules. (A) Total number of branches per cell, number of all detected microtubules. (B) Total length of branches per cell, the total length of all detected microtubules per cell. (C) Mean straightness index of detected microtubules per cell, the Euclidian distance between the starting and ending point of each branch divided by its full length. (D) Total number of junctions per cell. (E) Degree of branching per cell, number of skeletons (sets of branches, connected together) with more than one branch divided by the total number of skeletons in the image. (F) Mean number of junctions per skeleton, average number of branching points across all skeletons in the cell. Dots indicate analyzed images of individual cells. Pairwise comparisons were conducted using Tukey’s range test, NS indicates not significant differences (p > 0.05), otherwise differences are significant (p < 0.05).

Original Research

26 April 2022

Tubulin Cytoskeleton Organization in Cells of Determinate Nodules

Anna B. Kitaeva

, 4 more and

Viktor E. Tsyganov

2,708 views

3 citations

Natural variations affecting early nodule development and infection. (A) Nodule formation and intercellular infection in the absence of Nod factors and NF recognition/perception requires either an unknown mechanism or the activity of Type III secretion systems for the translocation of effector proteins in bradyrhizobia as well as the common symbiosis signaling pathway and other unknown proteins in Aeschynomene species and in soybean plants. (B) Nod Factor production of rhizobia and NF recognition/perception are required for the early symbiotic events such as root hair curling. (C) Initiation and progression of bacterial invasion through ITs are strictly controlled. The structure and amount of NFs determine whether NF receptors allow the initiation of IT development. Similarly, the presence of surface polysaccharides with correct structure is checked by the plants with help of receptors and unknown mechanisms. Unknown mechanisms and stress from the plants also might inhibit infection unless bacteria can deal with them, for example, by expressing the TypA stress protein. Bacterial effector molecules (Nops) resembling pathogen virulence factors transported into the plant cells and Effector Triggered Immunity often led to the restriction of infection, however, there are cases, when they have a positive effect on nodulation. Those bacterial macromolecules, whose lack or incorrect structure led to the arrest of the interaction with certain partners, and those plant proteins, which restrict the bacterial mutants or whose lack can be overturned, are shown in red. Plant molecules, as well as bacterial proteins/molecules, whose lack or presence (in parenthesis), that are able to overturn these defects, are shown in green. Those bacterial and corresponding plant proteins, that are responsible for incompatibility and a defect in either of them leads to compatibility, are shown in blue. If the compatibility needs both the plant and bacterial factors, the proteins are shown in brown. (??) denotes that the given factor has not been identified yet.

Review

11 April 2022

Varietas Delectat: Exploring Natural Variations in Nitrogen-Fixing Symbiosis Research

Ting Wang

, 2 more and

Attila Kereszt

2,842 views

6 citations

Gene expression analysis in potato roots ectopically expressing StSWEET7a. The impact of StSWEET7a overexpression on the colonization by R. irregularis was analyzed by qRT-PCR in roots of composite plants under the two experimental conditions (Exp1 and Exp2) using several symbiotic markers. (A) RiTEF and StPT4 expression, (B) StlnvCD141, (C) RiMST2, RiOLE1-like, StFatM. Transcript levels were normalized to StActin in the case of plant genes and RiTEF and to RiTEF in the case of fungal genes. Statistical significance was calculated either using a two-tailed Student’s T-test or the Mann–Whitney U test, depending on the normality, as explained in section “Materials and Methods.” Significance is given by p. Exact p-values are shown, ns, non-significant, p > 0.05; *p < 0.05; **p < 0.01.

Original Research

24 March 2022

Overexpression of the Potato Monosaccharide Transporter StSWEET7a Promotes Root Colonization by Symbiotic and Pathogenic Fungi by Increasing Root Sink Strength

Elisabeth Tamayo

, 2 more and

Natalia Requena

3,848 views

12 citations

Bioinformatic workflow for database construction. Symbols: cylinders, databases; circles, pipeline processes; rhomboids, annotations; squares, input data; balloons, partial results.

Original Research

25 March 2022

Deciphering Genomes: Genetic Signatures of Plant-Associated Micromonospora

Raúl Riesco

, 2 more and

Martha E. Trujillo

4,308 views

7 citations

Mini Review

28 March 2022

Multifarious and Interactive Roles of GRAS Transcription Factors During Arbuscular Mycorrhiza Development

Tania Ho-Plágaro

and

José Manuel García-Garrido

3,038 views

8 citations

Original Research

12 January 2022

The Role of Heterotrimeric G-Protein Beta Subunits During Nodulation in Medicago truncatula Gaertn and Pisum sativum L.

Andrey D. Bovin

, 3 more and

Elena A. Dolgikh

2,268 views

7 citations

Locations of perceived stress during the rhizobia-legume symbiosis. During symbiosis, there are three distinct environments that symbiotic bacteria must contend with: Bulk soil, the rhizosphere, and in planta. Each white box indicates potential “perceived” stressors that may be encountered in each of the indicated environments.

Review

03 January 2022

The Rhizobium-Legume Symbiosis: Co-opting Successful Stress Management

Justin P. Hawkins

and

Ivan J. Oresnik

The interaction of bacteria with plants can result in either a positive, negative, or neutral association. The rhizobium-legume interaction is a well-studied model system of a process that is considered a positive interaction. This process has evolved to require a complex signal exchange between the host and the symbiont. During this process, rhizobia are subject to several stresses, including low pH, oxidative stress, osmotic stress, as well as growth inhibiting plant peptides. A great deal of work has been carried out to characterize the bacterial response to these stresses. Many of the responses to stress are also observed to have key roles in symbiotic signaling. We propose that stress tolerance responses have been co-opted by the plant and bacterial partners to play a role in the complex signal exchange that occurs between rhizobia and legumes to establish functional symbiosis. This review will cover how rhizobia tolerate stresses, and how aspects of these tolerance mechanisms play a role in signal exchange between rhizobia and legumes.

11,753 views

54 citations