In: Phyton 57 (2017): S. 59-68 DOI: 10.12905/0380.phyton57-2018-0059 Published online on 12th February 2018


Published online on 12th February 2018

Different response of winter oilseed rape calli and seedlings to Leptosphaeria maculans

Katarzyna Hura, Tomasz Hura, Iwona Zur, Agnieszka Plazek & Marcin Rapacz

Key words: Winter oilseed rape, Brassica napus, ‘Bolko’, ‘Górczanski’, ‘Leo’, blackleg disease, Leptosphaeria maculans, Phoma lingam, callus, seedling, metabolic activity, Average Severity Index, heat emission, respiration intensity, enzymatic antioxidants, catalase, peroxidase, L-phenylalanine ammonia-lyase, soluble phenolics.

Summary
Hura K., Hura T., Zur I., Plazek A. & Rapacz M. 2018.

Different response of winter oilseed rape calli and seedlings to Leptosphaeria maculans. – Phyton (Horn, Austria) 57 (1–2): 59–68, with 8 figures.

The study investigated physiological and biochemical responses of winter oilseed rape (Brassica napus) callus and seedlings to secondary metabolites of Leptosphaeria maculans, an ascomycete causing stem canker. Three winter oilseed rape cultivars, ‘Leo’, ‘Bolko’, and ‘Górczanski’ were investigated during this study. The evaluated parameters included total phenolics content, the activity of L-phenylalanine ammonia-lyase, catalase and total peroxidases, respiration inten­sity, heat emission and metabolic activity. Callus elicitation and seedling inoculation were performed at 2 °C, and at op­timum growth temperature, i.e., 20 °C for the calli and 12 °C for the seedlings.
Elicited ‘Górczanski’ calli exhibited resistance to secondary metabolites of L. maculans, as only in this cultivar no drop in cell viability was observed, neither at 2 °C, nor at 20 °C. Similarly, a significant drop in average severity index (ASI) in hardened seedlings of the ‘Górczanski’ cultivar was linked to a stimulation of defense mechanisms triggered by low temperature. In the ‘Górczanski’ cultivar, the response of the calli and seedlings to L. maculans was identical, with the same pattern of changes for all analyzed parameters at both temperatures. In the ‘Leo’ cultivar, the same response of the calli and seedlings was observed for heat emission, catalase activity and phenolics content, however in the ‘Bolko’ cultivar only for cellular respiration. A similar response of ‘Górczanski’ calli and seedlings to L. maculans toxins was probably due to stable peroxidase activity.