A survey on basal resistance and riboflavin-induced defense responses of sugar beet against Rhizoctonia solani.
We examined basal defense responses and cytomolecular aspects of riboflavin-induced resistance (IR) in sugar beet-Rhizoctonia solani pathsystem by investigating H(2)O(2) burst, phenolics accumulation and analyzing the expression of phenylalanine ammonia-lyase (PAL) and peroxidase (cprx1) genes. Riboflavin was capable of priming plant defense responses via timely induction of H(2)O(2) production and phenolics accumulation. A correlation was found between induction of resistance by riboflavin and upregulation of PAL and cprx1 which are involved in phenylpropanoid signaling and phenolics metabolism. Application of peroxidase and PAL inhibitors suppressed not only basal resistance, but also riboflavin-IR of sugar beet to the pathogen. Treatment of the leaves with each inhibitor alone or together with riboflavin reduced phenolics accumulation which was correlated with higher level of disease progress. Together, these results demonstrate the indispensability of rapid H(2)O(2) accumulation, phenylpropanoid pathway and phenolics metabolism in basal defense and riboflavin-IR of sugar beet against R. solani.
Department of Crop Protection, Faculty of Agriculture, Ferdowsi University of Mashhad, PO Box 91775-1163, Mashhad, Iran. p-taheri@um.ac.ir
Parissa
P
Taheri
Saeed
S
Tarighi
D027461:Beta vulgaris / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D010544:Peroxidases / Q000037:antagonists & inhibitors / Q000235:genetics; D010636:Phenols / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000037:antagonists & inhibitors / Q000235:genetics; D017319:Photosensitizing Agents / Q000494:pharmacology*; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000187:drug effects* / Q000502:physiology; D018515:Plant Leaves / Q000187:drug effects / Q000382:microbiology / Q000502:physiology; D016897:Respiratory Burst / Q000187:drug effects; D012232:Rhizoctonia / Q000276:immunology* / Q000472:pathogenicity; D012256:Riboflavin / Q000494:pharmacology*; D015398:Signal Transduction; D013997:Time Factors
D010636:Phenols; D017319:Photosensitizing Agents; D006861:Hydrogen Peroxide; D010544:Peroxidases; D010650:Phenylalanine Ammonia-Lyase; D012256:Riboflavin