Journal ArticleDOI
A further study on the rôle of hypersensitivity in resistance of potato cultivars to infection by an incompatible race of Phytophthora infestans
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TLDR
The results indicated that the degree of resistance among resistant cultivars depended primarily on the rate of occurrence of hypersensitivity and the associated accumulation of rishitin.Abstract:
Using 12 potato cultivars having various R -genes and apparently different degrees of resistance to an incompatible race of Phytophthora infestans , relationships were investigated between (1) the percentage of cells reacting hypersensitively, (2) the number of dead and brown cells at late stages of infection, (3) the accumulation of rishitin and (4) the restriction of fungal growth. The number of invaded and browned cells of aged tuber discs 2 days after inoculation was lower than that of fresh tuber discs and, within each cultivar, was negatively correlated with the percentage of hypersensitive cells observed 7 h after inoculation. Hypersensitivity within 7 h after inoculation evidently contributed to the localization of the invading fungi in the hypersensitive cells by stimulating the accumulation of phytoalexin in these cells to an inhibitory level at 12 h after inoculation, when invading fungi were about to grow through the invaded cells to the other cells. In less resistant cultivars, the percentage of hypersensitive cells after 7 h was low and hyphae grew into deeper layers of cells, some of which became brown. More rishtin accumulated in these cultivars: the amount being related to the number of brown cells 24 h after inoculation but not with the number at later times. These results indicated that the degree of resistance among resistant cultivars depended primarily on the rate of occurrence of hypersensitivity and the associated accumulation of rishitin.read more
Citations
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Journal ArticleDOI
Involvement of superoxide anion generation in the hypersensitive response of potato tuber tissues to infection with an incompatible race of Phytophthora infestans and to the hyphal wall components
TL;DR: Results indicate that an O 2 − -generating system may be activated in potato tissues during the incompatible interaction induced by invading fungi or fungal wall components, and also that the generation of O 1 − may be involved during hypersensitive cell death as a trigger of the sequence of resistance reactions.
Journal ArticleDOI
The phytoalexin response: elicitation, signalling and control of host gene expression
TL;DR: The present review considers the process of phytoalexin induction, at the molecular level, from the fungal elicitor to the early changes in host gene expression associated with its action.
Journal ArticleDOI
The oxidative burst protects plants against pathogen attack: Mechanism and role as an emergency signal for plant bio-defence — a review
Noriyuki Doke,Yoshio Miura,L. M. Sanchez,Hae-Jun Park,Tomoya Noritake,Hirofumi Yoshioka,Kazuhito Kawakita +6 more
TL;DR: The oxidative burst may play the role of an internal emergency signal for induction of the metabolic cascade for active defence in Solanaceae plants and Phytophthora spp.
Journal ArticleDOI
Tansley Review No. 86 Accumulation of phytoalexins: defence mechanism and stimulus response system.
TL;DR: Transgenic and mutant plants with specific alterations in one or more ot those elements necessary for the plant to respond to the signals for phytoalexin synthesis and other defence responses, are beginning to aid resolution of the complex pattern ot signalling events and the respective roles of the inducible defence mechanisms in resistance.
Journal ArticleDOI
NADPH-dependent O2− generation in membrane fractions isolated from wounded potato tubers inoculated with Phytophthora infestans
TL;DR: It is suggested that a novel O2− generating NADPH oxidase system in the membrane of potato tissues may be activated following an incompatible cell reaction, which results in hypersensitive cell death and phytoalexin production.
References
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Journal ArticleDOI
Hypersensitivity as a Consequence, Not the Cause, of Plant Resistance to Infection
TL;DR: The early observations of Ward1 and Stakman2 on wheat rusts resulted in the formation of the concept of the hypersensitive response of a resistant host plant to infection.
Journal ArticleDOI
Partial characterization and aspects of the mode of action of a hypersensitivity-inhibiting factor (HIF) isolated from Phytophthora infestans
TL;DR: The data suggest that the compatible interaction between potato tissue and P. infestans may be caused by a suppression of the hypersensitive response of the host tissue by water-soluble glucans from the fungus.
Journal ArticleDOI
Effect of hyphal wall components from Phytophthora infestans on protoplasts of potato tuber tissues
Noriyuki Doke,Kohei Tomiyama +1 more
TL;DR: Examination of hyphal wall components of various races of Phytophthora infestans on protoplasts prepared from tuber tissues of potato cultivars having various resistance genes to the pathogen suggested a possibility that the recognition sites of theprotoplasts for the fungal components may reside in the protoplasmic membrane, resulting in occurrence of a hypersensitive reaction in potato cells.
Journal ArticleDOI
Suppression of the hypersensitive response of potato tuber protoplasts to hyphal wall components by water soluble glucans isolated from Phytophthora infestans.
Noriyuki Doke,Kohei Tomiyama +1 more
TL;DR: Results suggested that glucans from P. infestans may be a determinant of host-parasite specificity in potato late blight as a suppressor of the effects of hyphal wall components on elicitation of the hypersensitive reaction.
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Suppression of the hypersensitive response of potato tuber protoplasts to hyphal wall components by water soluble glucans isolated from Phytophthora infestans.
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