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Histology of Sclerotium cepivorum infection of onion roots and the spatial relationships of pectinases in the infection process

Citation

Metcalf, DA and Wilson, CR, Histology of Sclerotium cepivorum infection of onion roots and the spatial relationships of pectinases in the infection process, Plant Pathology, 48, (4) pp. 445-452. ISSN 0032-0862 (1999) [Refereed Article]

DOI: doi:10.1046/j.1365-3059.1999.00370.x

Abstract

Sclerotium cepivorum (isolate Sc4) hyphae penetrated the epidermis and hypodermis of onion roots and grew into the cortex. Immediately following penetration only the cells through which S. cepivorum grew were lysed, but subsequently cells were killed and cell walls disintegrated ahead of the infection hyphae. Sclerotium cepivorum produced two polygalacturonases (PG) and two pectinesterases (PE) in culture. These isozymes were also found in infected onion root tissues and another PG and a PE were occasionally detected. Two isozymes of PG and three isozymes of PE diffused ahead of the infection hyphae. The spatial distribution of these enzymes was associated with cell death and cell wall degradation. The epidermis, hypodermis, endodermis and vascular tissues were more resistant to hydrolysis than the cortex, but only the endodermis and cells within it retained nuclei following hydrolysis of the surrounding cortical tissues. The cavity within the root cortex became filled with swollen, vacuolate S. cepivorum hyphae.

Item Details

Item Type:Refereed Article
Research Division:Agricultural and Veterinary Sciences
Research Group:Horticultural Production
Research Field:Horticultural Crop Protection (Pests, Diseases and Weeds)
Objective Division:Plant Production and Plant Primary Products
Objective Group:Horticultural Crops
Objective Field:Vegetables
Author:Metcalf, DA (Mr Dean Metcalf)
Author:Wilson, CR (Associate Professor Calum Wilson)
ID Code:16917
Year Published:1999
Web of Science® Times Cited:8
Deposited By:Tasmanian Institute of Agriculture
Deposited On:1999-08-01
Last Modified:2011-11-24
Downloads:0

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