Limits...
Intra and Inter-Spore Variability in Rhizophagus irregularis AOX Gene.

Campos C, Cardoso H, Nogales A, Svensson J, Lopez-Ráez JA, Pozo MJ, Nobre T, Schneider C, Arnholdt-Schmitt B - PLoS ONE (2015)

Bottom Line: Nevertheless, virtually nothing is known on the involvement of AMF AOX on symbiosis establishment, as well on the existence of AOX variability that could affect AMF effectiveness and consequently plant performance.The analysis of RiAOX polymorphisms in single spores of three different isolates showed a reduced variability in one spore relatively to a group of spores.A high number of polymorphisms occurred in introns; nevertheless, some putative amino acid changes resulting from non-synonymous variants were found, offering a basis for selective pressure to occur within the populations.

View Article: PubMed Central - PubMed

Affiliation: EU Marie Curie Chair, ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, IIFA-Instituto de Formação e Investigação Avançada, Universidade de Évora, Núcleo da Mitra, Évora, Portugal.

ABSTRACT
Arbuscular mycorrhizal fungi (AMF) are root-inhabiting fungi that form mutualistic symbioses with their host plants. AMF symbiosis improves nutrient uptake and buffers the plant against a diversity of stresses. Rhizophagus irregularis is one of the most widespread AMF species in the world, and its application in agricultural systems for yield improvement has increased over the last years. Still, from the inoculum production perspective, a lack of consistency of inoculum quality is referred to, which partially may be due to a high genetic variability of the fungus. The alternative oxidase (AOX) is an enzyme of the alternative respiratory chain already described in different taxa, including various fungi, which decreases the damage caused by oxidative stress. Nevertheless, virtually nothing is known on the involvement of AMF AOX on symbiosis establishment, as well on the existence of AOX variability that could affect AMF effectiveness and consequently plant performance. Here, we report the isolation and characterisation of the AOX gene of R. irregularis (RiAOX), and show that it is highly expressed during early phases of the symbiosis with plant roots. Phylogenetic analysis clustered RiAOX sequence with ancient fungi, and multiple sequence alignment revealed the lack of several regulatory motifs which are present in plant AOX. The analysis of RiAOX polymorphisms in single spores of three different isolates showed a reduced variability in one spore relatively to a group of spores. A high number of polymorphisms occurred in introns; nevertheless, some putative amino acid changes resulting from non-synonymous variants were found, offering a basis for selective pressure to occur within the populations. Given the AOX relatedness with stress responses, differences in gene variants amongst R. irregularis isolates are likely to be related with its origin and environmental constraints and might have a potential impact on inoculum production.

No MeSH data available.


Related in: MedlinePlus

Comparison of exon-intron structure of AOX gene in R. irregularis and fungi from other phyla.Introns are represented by dashed lines and exons by blue rectangles. The green rectangles represent the location of the AOX encoded conserved domain, within the exons.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4634980&req=5

pone.0142339.g001: Comparison of exon-intron structure of AOX gene in R. irregularis and fungi from other phyla.Introns are represented by dashed lines and exons by blue rectangles. The green rectangles represent the location of the AOX encoded conserved domain, within the exons.

Mentions: The full-length gene sequence of R. irregularis AOX has been deposited in GenBank (accession numbers KT423114 and KT423115). At the genomic level, RiAOX is composed by 4 exons interrupted by 3 introns, with a total size of 1250 bp (Fig 1). Variability among the exons and the introns within the RiAOX sequence is observed. The gene coding sequence, with 1032 bp and coding for a putative peptide of 343 aa, is composed by exon 1 (444 bp), exon 2 (116 bp), exon 3 (188 bp) and exon 4 (281 bp). The introns are considerably shorter, having 69, 81 and 68 bp for introns 1, 2 and 3, respectively.


Intra and Inter-Spore Variability in Rhizophagus irregularis AOX Gene.

Campos C, Cardoso H, Nogales A, Svensson J, Lopez-Ráez JA, Pozo MJ, Nobre T, Schneider C, Arnholdt-Schmitt B - PLoS ONE (2015)

Comparison of exon-intron structure of AOX gene in R. irregularis and fungi from other phyla.Introns are represented by dashed lines and exons by blue rectangles. The green rectangles represent the location of the AOX encoded conserved domain, within the exons.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4634980&req=5

pone.0142339.g001: Comparison of exon-intron structure of AOX gene in R. irregularis and fungi from other phyla.Introns are represented by dashed lines and exons by blue rectangles. The green rectangles represent the location of the AOX encoded conserved domain, within the exons.
Mentions: The full-length gene sequence of R. irregularis AOX has been deposited in GenBank (accession numbers KT423114 and KT423115). At the genomic level, RiAOX is composed by 4 exons interrupted by 3 introns, with a total size of 1250 bp (Fig 1). Variability among the exons and the introns within the RiAOX sequence is observed. The gene coding sequence, with 1032 bp and coding for a putative peptide of 343 aa, is composed by exon 1 (444 bp), exon 2 (116 bp), exon 3 (188 bp) and exon 4 (281 bp). The introns are considerably shorter, having 69, 81 and 68 bp for introns 1, 2 and 3, respectively.

Bottom Line: Nevertheless, virtually nothing is known on the involvement of AMF AOX on symbiosis establishment, as well on the existence of AOX variability that could affect AMF effectiveness and consequently plant performance.The analysis of RiAOX polymorphisms in single spores of three different isolates showed a reduced variability in one spore relatively to a group of spores.A high number of polymorphisms occurred in introns; nevertheless, some putative amino acid changes resulting from non-synonymous variants were found, offering a basis for selective pressure to occur within the populations.

View Article: PubMed Central - PubMed

Affiliation: EU Marie Curie Chair, ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, IIFA-Instituto de Formação e Investigação Avançada, Universidade de Évora, Núcleo da Mitra, Évora, Portugal.

ABSTRACT
Arbuscular mycorrhizal fungi (AMF) are root-inhabiting fungi that form mutualistic symbioses with their host plants. AMF symbiosis improves nutrient uptake and buffers the plant against a diversity of stresses. Rhizophagus irregularis is one of the most widespread AMF species in the world, and its application in agricultural systems for yield improvement has increased over the last years. Still, from the inoculum production perspective, a lack of consistency of inoculum quality is referred to, which partially may be due to a high genetic variability of the fungus. The alternative oxidase (AOX) is an enzyme of the alternative respiratory chain already described in different taxa, including various fungi, which decreases the damage caused by oxidative stress. Nevertheless, virtually nothing is known on the involvement of AMF AOX on symbiosis establishment, as well on the existence of AOX variability that could affect AMF effectiveness and consequently plant performance. Here, we report the isolation and characterisation of the AOX gene of R. irregularis (RiAOX), and show that it is highly expressed during early phases of the symbiosis with plant roots. Phylogenetic analysis clustered RiAOX sequence with ancient fungi, and multiple sequence alignment revealed the lack of several regulatory motifs which are present in plant AOX. The analysis of RiAOX polymorphisms in single spores of three different isolates showed a reduced variability in one spore relatively to a group of spores. A high number of polymorphisms occurred in introns; nevertheless, some putative amino acid changes resulting from non-synonymous variants were found, offering a basis for selective pressure to occur within the populations. Given the AOX relatedness with stress responses, differences in gene variants amongst R. irregularis isolates are likely to be related with its origin and environmental constraints and might have a potential impact on inoculum production.

No MeSH data available.


Related in: MedlinePlus