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Deciphering the Niches of Colonisation of Vitis vinifera L. by the Esca-Associated Fungus Phaeoacremonium aleophilum Using a gfp Marked Strain and Cutting Systems.

Pierron R, Gorfer M, Berger H, Jacques A, Sessitsch A, Strauss J, Compant S - PLoS ONE (2015)

Bottom Line: The fungus was however detected in xylem vessels, bark and inside the pith twelve weeks post-inoculation.These results demonstrate that P. aleophilum colonisation can vary according to the type of tissues and the type of spread using pith, bark and fibres.Woody tissues can respond to the injury and to the presence of this fungus, and xylem fibres play a key role in the early colonisation of the internode by P. aleophilum before the fungus can colonise xylem vessels.

View Article: PubMed Central - PubMed

Affiliation: Université de Toulouse, Equipe Vins Viticulture et Œnologie, Département des Sciences Agronomiques et Agroalimentaires, INP-EI Purpan, 75 voie du T.O.E.C. BP57611, Toulouse, France; University of Natural Resources and Life Sciences, Department of Applied Genetics and Cell Biology, Tulln, Austria.

ABSTRACT

Introduction: Esca disease has become a major threat for viticulture. Phaeoacremonium aleophilum is considered a pioneer of the esca complex pathosystem, but its colonisation behaviour inside plants remains poorly investigated.

Material and methods: In this study, P. aleophilum::gfp7 colonisation was assessed six and twelve weeks post-inoculation in two different types of tissues: in the node and the internode of one year-old rooted cuttings of Cabernet Sauvignon. These processes of colonisation were compared with the colonisation by the wild-type strain using a non-specific lectin probe Alexa Fluor 488-WGA.

Results: Data showed that six weeks post-inoculation of the internode, the fungus had colonised the inoculation point, the bark and xylem fibres. Bark, pith and xylem fibres were strongly colonised by the fungus twelve weeks post-inoculation and it can progress up to 8 mm from the point of inoculation using pith, bark and fibres. P. aleophilum was additionally detected in the lumen of xylem vessels in which tyloses blocked its progression. Different plant responses in specific tissues were additionally visualised. Inoculation of nodes led to restricted colonisation of P. aleophilum and this colonisation was associated with a plant response six weeks post-inoculation. The fungus was however detected in xylem vessels, bark and inside the pith twelve weeks post-inoculation.

Conclusions: These results demonstrate that P. aleophilum colonisation can vary according to the type of tissues and the type of spread using pith, bark and fibres. Woody tissues can respond to the injury and to the presence of this fungus, and xylem fibres play a key role in the early colonisation of the internode by P. aleophilum before the fungus can colonise xylem vessels.

No MeSH data available.


Related in: MedlinePlus

Observation of internodal longitudinal sections of Cabernet Sauvignon clone 15 cuttings challenged with wild-type P. aleophilum CBS 100398 (arrows) six weeks post-inoculation and stained with Alexa Fluor 488-WGA.A) Inoculation point colonised by P. aleophilum. B-C) Mock control. D) Damaged bark covered with wild-type P. aleophilum. E) Parenchymal cells colonised by P. aleophilum, close to xylem fibres. F) Xylem fibres strongly colonised by wild-type P. aleophilum. G) Parenchymal cells from the mock control. H) Pith colonised by few hyphae. I) Mock control pith colonised by few natural endophytes. Fib.: fibres, Inoc. point: inoculation point, Par.: parenchyma.
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pone.0126851.g005: Observation of internodal longitudinal sections of Cabernet Sauvignon clone 15 cuttings challenged with wild-type P. aleophilum CBS 100398 (arrows) six weeks post-inoculation and stained with Alexa Fluor 488-WGA.A) Inoculation point colonised by P. aleophilum. B-C) Mock control. D) Damaged bark covered with wild-type P. aleophilum. E) Parenchymal cells colonised by P. aleophilum, close to xylem fibres. F) Xylem fibres strongly colonised by wild-type P. aleophilum. G) Parenchymal cells from the mock control. H) Pith colonised by few hyphae. I) Mock control pith colonised by few natural endophytes. Fib.: fibres, Inoc. point: inoculation point, Par.: parenchyma.

Mentions: Using Alexa Fluor 488-WGA, hyphae or short hyphae were detected near the inoculation point at the internodal level. Fibres were especially observed to be intensively colonised in plants subjected to the P. aleophilum wild-type strain (Fig 5A) around the point of inoculation in comparison to the mock control (Fig 5B). Hyphae, conidia or germinated conidia were additionally detected in the bark (Fig 5D), few in parenchymal cells (Fig 5E) and in fibres (Fig 5F). The pith seemed to be sparsely colonised (Fig 5H) in comparison to the mock control (Fig 5I). Few microbes, that may represent natural endophytes of cuttings, were detected in control plants in different tissues (Fig 5C and 5I). In parenchyma of control plants no microbe was detected (Fig 5G). A small amount of fungi and bacteria has been additionally detected in the lumen of xylem vessels of mock-treated plants but most of the samples did not reveal any hyphae in this cell layer (Fig 5I).


Deciphering the Niches of Colonisation of Vitis vinifera L. by the Esca-Associated Fungus Phaeoacremonium aleophilum Using a gfp Marked Strain and Cutting Systems.

Pierron R, Gorfer M, Berger H, Jacques A, Sessitsch A, Strauss J, Compant S - PLoS ONE (2015)

Observation of internodal longitudinal sections of Cabernet Sauvignon clone 15 cuttings challenged with wild-type P. aleophilum CBS 100398 (arrows) six weeks post-inoculation and stained with Alexa Fluor 488-WGA.A) Inoculation point colonised by P. aleophilum. B-C) Mock control. D) Damaged bark covered with wild-type P. aleophilum. E) Parenchymal cells colonised by P. aleophilum, close to xylem fibres. F) Xylem fibres strongly colonised by wild-type P. aleophilum. G) Parenchymal cells from the mock control. H) Pith colonised by few hyphae. I) Mock control pith colonised by few natural endophytes. Fib.: fibres, Inoc. point: inoculation point, Par.: parenchyma.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4464894&req=5

pone.0126851.g005: Observation of internodal longitudinal sections of Cabernet Sauvignon clone 15 cuttings challenged with wild-type P. aleophilum CBS 100398 (arrows) six weeks post-inoculation and stained with Alexa Fluor 488-WGA.A) Inoculation point colonised by P. aleophilum. B-C) Mock control. D) Damaged bark covered with wild-type P. aleophilum. E) Parenchymal cells colonised by P. aleophilum, close to xylem fibres. F) Xylem fibres strongly colonised by wild-type P. aleophilum. G) Parenchymal cells from the mock control. H) Pith colonised by few hyphae. I) Mock control pith colonised by few natural endophytes. Fib.: fibres, Inoc. point: inoculation point, Par.: parenchyma.
Mentions: Using Alexa Fluor 488-WGA, hyphae or short hyphae were detected near the inoculation point at the internodal level. Fibres were especially observed to be intensively colonised in plants subjected to the P. aleophilum wild-type strain (Fig 5A) around the point of inoculation in comparison to the mock control (Fig 5B). Hyphae, conidia or germinated conidia were additionally detected in the bark (Fig 5D), few in parenchymal cells (Fig 5E) and in fibres (Fig 5F). The pith seemed to be sparsely colonised (Fig 5H) in comparison to the mock control (Fig 5I). Few microbes, that may represent natural endophytes of cuttings, were detected in control plants in different tissues (Fig 5C and 5I). In parenchyma of control plants no microbe was detected (Fig 5G). A small amount of fungi and bacteria has been additionally detected in the lumen of xylem vessels of mock-treated plants but most of the samples did not reveal any hyphae in this cell layer (Fig 5I).

Bottom Line: The fungus was however detected in xylem vessels, bark and inside the pith twelve weeks post-inoculation.These results demonstrate that P. aleophilum colonisation can vary according to the type of tissues and the type of spread using pith, bark and fibres.Woody tissues can respond to the injury and to the presence of this fungus, and xylem fibres play a key role in the early colonisation of the internode by P. aleophilum before the fungus can colonise xylem vessels.

View Article: PubMed Central - PubMed

Affiliation: Université de Toulouse, Equipe Vins Viticulture et Œnologie, Département des Sciences Agronomiques et Agroalimentaires, INP-EI Purpan, 75 voie du T.O.E.C. BP57611, Toulouse, France; University of Natural Resources and Life Sciences, Department of Applied Genetics and Cell Biology, Tulln, Austria.

ABSTRACT

Introduction: Esca disease has become a major threat for viticulture. Phaeoacremonium aleophilum is considered a pioneer of the esca complex pathosystem, but its colonisation behaviour inside plants remains poorly investigated.

Material and methods: In this study, P. aleophilum::gfp7 colonisation was assessed six and twelve weeks post-inoculation in two different types of tissues: in the node and the internode of one year-old rooted cuttings of Cabernet Sauvignon. These processes of colonisation were compared with the colonisation by the wild-type strain using a non-specific lectin probe Alexa Fluor 488-WGA.

Results: Data showed that six weeks post-inoculation of the internode, the fungus had colonised the inoculation point, the bark and xylem fibres. Bark, pith and xylem fibres were strongly colonised by the fungus twelve weeks post-inoculation and it can progress up to 8 mm from the point of inoculation using pith, bark and fibres. P. aleophilum was additionally detected in the lumen of xylem vessels in which tyloses blocked its progression. Different plant responses in specific tissues were additionally visualised. Inoculation of nodes led to restricted colonisation of P. aleophilum and this colonisation was associated with a plant response six weeks post-inoculation. The fungus was however detected in xylem vessels, bark and inside the pith twelve weeks post-inoculation.

Conclusions: These results demonstrate that P. aleophilum colonisation can vary according to the type of tissues and the type of spread using pith, bark and fibres. Woody tissues can respond to the injury and to the presence of this fungus, and xylem fibres play a key role in the early colonisation of the internode by P. aleophilum before the fungus can colonise xylem vessels.

No MeSH data available.


Related in: MedlinePlus