Histological and histochemical detection of defence responses in pine embryos challenged in vitro with Heterobasidion annosum

V R Nsolomo, Stephen Woodward

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7 Citations (Scopus)

Abstract

Embryos of Pinus sylvestris, Pinus nigra var. maritima and Pinus contorta were inoculated in vitro with Heterobasidion annosum and the histology and histochemistry of the host response determined. Three days after challenge, intercellular penetration of hyphae through the epidermis and into the cortex of the host species had occurred. In cells close to the invading hyphae, cell walls became thickened in all three pine species. Lignification and suberization of cell walls in the cortex was detectable in P. nigra var. maritima and P. contorta, but not in P, sylvestris. Moreover, cells in the cortex of P. nigra var. maritima and P. contorta became occluded with dense deposits staining positively for phenolic and lipidic materials. Starch grains had accumulated in host cells close to sites of penetration by day 3, and levels appeared to increase by day 6, except for tissues where heavy invasion by H. annosum had occurred. Host responses intensified between 3 and 6 days after challenge. By day 6, however, the pathogen had penetrated as far as the stele and into the developing xy]em vessels. Nine days after challenge, host tissues contained abundant intra- and inter-cellular hyphae, causing severe disruption and disintegration of all tissues. The utility of such in vitro systems in studies on the resistance responses of conifers to challenge with fungal pathogens is discussed.

Original languageEnglish
Pages (from-to)187-195
Number of pages9
JournalEuropean Journal of Forest Pathology
Volume27
Issue number3
Publication statusPublished - Jun 1997

Keywords

  • NORWAY SPRUCE
  • ROOTS
  • RESISTANCE
  • INFECTION
  • INVITRO
  • PICEA
  • SEEDLINGS
  • PATHOGENS
  • FUSIFORME
  • CALLI

Cite this

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title = "Histological and histochemical detection of defence responses in pine embryos challenged in vitro with Heterobasidion annosum",
abstract = "Embryos of Pinus sylvestris, Pinus nigra var. maritima and Pinus contorta were inoculated in vitro with Heterobasidion annosum and the histology and histochemistry of the host response determined. Three days after challenge, intercellular penetration of hyphae through the epidermis and into the cortex of the host species had occurred. In cells close to the invading hyphae, cell walls became thickened in all three pine species. Lignification and suberization of cell walls in the cortex was detectable in P. nigra var. maritima and P. contorta, but not in P, sylvestris. Moreover, cells in the cortex of P. nigra var. maritima and P. contorta became occluded with dense deposits staining positively for phenolic and lipidic materials. Starch grains had accumulated in host cells close to sites of penetration by day 3, and levels appeared to increase by day 6, except for tissues where heavy invasion by H. annosum had occurred. Host responses intensified between 3 and 6 days after challenge. By day 6, however, the pathogen had penetrated as far as the stele and into the developing xy]em vessels. Nine days after challenge, host tissues contained abundant intra- and inter-cellular hyphae, causing severe disruption and disintegration of all tissues. The utility of such in vitro systems in studies on the resistance responses of conifers to challenge with fungal pathogens is discussed.",
keywords = "NORWAY SPRUCE, ROOTS, RESISTANCE, INFECTION, INVITRO, PICEA, SEEDLINGS, PATHOGENS, FUSIFORME, CALLI",
author = "Nsolomo, {V R} and Stephen Woodward",
year = "1997",
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language = "English",
volume = "27",
pages = "187--195",
journal = "European Journal of Forest Pathology",
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TY - JOUR

T1 - Histological and histochemical detection of defence responses in pine embryos challenged in vitro with Heterobasidion annosum

AU - Nsolomo, V R

AU - Woodward, Stephen

PY - 1997/6

Y1 - 1997/6

N2 - Embryos of Pinus sylvestris, Pinus nigra var. maritima and Pinus contorta were inoculated in vitro with Heterobasidion annosum and the histology and histochemistry of the host response determined. Three days after challenge, intercellular penetration of hyphae through the epidermis and into the cortex of the host species had occurred. In cells close to the invading hyphae, cell walls became thickened in all three pine species. Lignification and suberization of cell walls in the cortex was detectable in P. nigra var. maritima and P. contorta, but not in P, sylvestris. Moreover, cells in the cortex of P. nigra var. maritima and P. contorta became occluded with dense deposits staining positively for phenolic and lipidic materials. Starch grains had accumulated in host cells close to sites of penetration by day 3, and levels appeared to increase by day 6, except for tissues where heavy invasion by H. annosum had occurred. Host responses intensified between 3 and 6 days after challenge. By day 6, however, the pathogen had penetrated as far as the stele and into the developing xy]em vessels. Nine days after challenge, host tissues contained abundant intra- and inter-cellular hyphae, causing severe disruption and disintegration of all tissues. The utility of such in vitro systems in studies on the resistance responses of conifers to challenge with fungal pathogens is discussed.

AB - Embryos of Pinus sylvestris, Pinus nigra var. maritima and Pinus contorta were inoculated in vitro with Heterobasidion annosum and the histology and histochemistry of the host response determined. Three days after challenge, intercellular penetration of hyphae through the epidermis and into the cortex of the host species had occurred. In cells close to the invading hyphae, cell walls became thickened in all three pine species. Lignification and suberization of cell walls in the cortex was detectable in P. nigra var. maritima and P. contorta, but not in P, sylvestris. Moreover, cells in the cortex of P. nigra var. maritima and P. contorta became occluded with dense deposits staining positively for phenolic and lipidic materials. Starch grains had accumulated in host cells close to sites of penetration by day 3, and levels appeared to increase by day 6, except for tissues where heavy invasion by H. annosum had occurred. Host responses intensified between 3 and 6 days after challenge. By day 6, however, the pathogen had penetrated as far as the stele and into the developing xy]em vessels. Nine days after challenge, host tissues contained abundant intra- and inter-cellular hyphae, causing severe disruption and disintegration of all tissues. The utility of such in vitro systems in studies on the resistance responses of conifers to challenge with fungal pathogens is discussed.

KW - NORWAY SPRUCE

KW - ROOTS

KW - RESISTANCE

KW - INFECTION

KW - INVITRO

KW - PICEA

KW - SEEDLINGS

KW - PATHOGENS

KW - FUSIFORME

KW - CALLI

M3 - Article

VL - 27

SP - 187

EP - 195

JO - European Journal of Forest Pathology

JF - European Journal of Forest Pathology

SN - 0300-1237

IS - 3

ER -