Progress of snow mould infection in crowns of winter rye (Secale cereale L.) is related to photosynthetic activity during cold acclimation

• Published in: Plant physiology and biochemistry 2013-09, Vol.70, p.360-367
• Main Authors: Pociecha, E., Janowiak, F., Dubas, E., Żur, I., Tokarz, K., Kolasińska, I., Płażek, A.
• Format: Article
• Language: English
• Subjects: Abscisic acid; Abscisic Acid - genetics; Abscisic Acid - metabolism; acclimation; Acclimatization - genetics; biochemical pathways; Biological and medical sciences; Breeding; callose; Carbohydrate Metabolism - genetics; carbon dioxide; Carbon Dioxide - metabolism; carboxylation; cold; Cold acclimation; Cold Temperature; cortex; Disease Resistance - genetics; electron transfer; Electron Transport; Fundamental and applied biological sciences. Psychology; Fungi; genes; Genotype; Glucans - metabolism; inbred lines; leaves; Microdochium nivale; Monographella nivalis; pathogenesis; pathogens; Phenotype; Photosynthesis; Photosynthesis - genetics; Phytopathogenesis; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - genetics; Plant Diseases - microbiology; plant growth; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant physiology and development; ribulose-bisphosphate carboxylase; Ribulose-Bisphosphate Carboxylase - genetics; Ribulose-Bisphosphate Carboxylase - metabolism; rye; Secale - genetics; Secale - metabolism; Secale - physiology; Secale cereale; snow; Stress, Physiological - genetics; Total soluble carbohydrates
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2013.05.033

Resistance to snow mould is a feature determined by multiple genes. Therefore, determining the phenotype of resistant plants is difficult as it requires an investigation over a long period of time from cold acclimation through pathogenesis. The aim of the present study was (i) to determine the characteristics of the resistant genotype and (ii) to clarify the connections between photosynthesis during cold acclimation and then pathogenesis caused by Microdochium nivale. Two inbred lines of winter rye (Secale cereale L.) differing in their susceptibility to snow mould were used in the study. After cold acclimation snow mould resistant (SMR) line was characterised by higher values of CO2 assimilation and electron transport efficiency but did not differ from snow mould susceptible (SMS) line in carboxylation rate of RuBisCO (Vcmax). Higher soluble carbohydrate accumulation, due to higher photosynthesis intensity, as well as an ABA increase at 5 days post infection (DPI) in leaves and crowns were found in SMR line during the pathogenesis period. Callose deposition was found around non-infected bundle sheets and in cortex cells at 5 DPI (at the same time point as ABA peak) only in SMR line, which probably prevented the infection of leaf initials. Early leaf initials infection in SMS line may be responsible for inhibiting leaf growth and plant regeneration after stress cessation. The results show different physiological and biochemical characteristics of the investigated lines, which can be applied in the selection of resistant genotypes and identifying genomic regions responsible for metabolic pathways increasing pathogen resistance. •Pink snow mould resistance features were examined in leaves and crowns.•Carbohydrates are the connection between cold acclimation and pathogenesis.•Chloroplastic triose-phosphate export and sugar synthesis shape pathogen resistance.•ABA dependent callose synthesis prevents the infection of leaf initials.