Dem IPB wird erneut ein beispielhaftes Handeln im Sinne einer chancengleichheitsorientierten Personal- und Organisationspolitik bescheinigt. Das Institut erhält zum 6. Mal in Folge das TOTAL E-QUALITY…
Die Plant Science Student Conference (PSSC) wird seit 20 Jahren im jährlichen Wechsel von Studierenden der beiden Leibniz-Institute IPK und IPB organisiert. Im Interview erläutern Christina Wäsch…
Trujillo, M.; TROEGER, M.; NIKS, R. E.; Kogel, K.-H.; Hückelhoven, R.;Mechanistic and genetic overlap of barley host and non-host resistance to Blumeria graminisMol. Plant Pathol.5389-396(2004)DOI: 10.1111/j.1364-3703.2004.00238.x
Non‐host resistance of barley to Blumeria graminis f.sp. tritici (Bgt ), an inappropriate forma specialis of the grass powdery mildew fungus, is associated with formation of cell wall appositions (papillae) at sites of attempted fungal penetration and a hypersensitive cell death reaction (HR) of single attacked cells. Penetration resistance and HR are also typical features of race‐non‐specific and race‐specific resistance of barley to the appropriate Blumeria graminis f.sp. hordei (Bgh ), raising the question of whether genotypic differences in the cellular response of barley to Bgt are detectable. First, we analysed fungal penetration frequencies and HR in different barley accessions known to show altered non‐host resistance. In genotypes with limited resistance to inappropriate cereal rust fungi, we concomitantly detected low penetration resistance to Bgt and significant differences of HR rates during attack from Bgt . Second, we tested barley mutants known to show altered host responses to Bgh . The rar1‐mutation that suppresses many types of race‐cultivar‐specific resistances did not influence the non‐host response of the Bgt‐isolate used in this study. However, mutants of Ror1 and Ror2 , two genes required for full race non‐specific penetration resistance of mlo‐barley to barley powdery mildew fungus, exhibited altered defence response to Bgt , including higher frequencies of fungal penetration. On these mutants, growth of the inappropriate fungus was arrested subsequent to penetration by HR. Together, the data show that barley defence response to the wheat powdery mildew fungus is determined by similar factors as race‐specific and race‐non‐specific resistance to appropriate Bgh.
Publikation
NICKSTADT, A.; THOMMA, B. P. H. J.; Feussner, I.; Kangasjärvi, J.; ZEIER, J.; LOEFFLER, C.; Scheel, D.; BERGER, S.;The jasmonate-insensitive mutant jin1 shows increased resistance to biotrophic as well as necrotrophic pathogensMol. Plant Pathol.5425-434(2004)DOI: 10.1111/j.1364-3703.2004.00242.x
Jasmonic acid and related oxylipin compounds are plant signalling molecules that are involved in the response to pathogens, insects, wounding and ozone. To explore further the role of jasmonates in stress signal transduction, the response of two jasmonate‐signalling mutants, jin1 and jin4 , to pathogens and ozone was analysed in this study. Upon treatment with the biotrophic bacterial pathogen Pseudomonas syringae , endogenous jasmonate levels increased in jin1 and jin4 similar to wild‐type, demonstrating that these mutants are not defective in jasmonate biosynthesis. Jin1 but not jin4 is more resistant to P. syringae and this higher resistance is accompanied by higher levels of salicylic acid. Jin1 is also more resistant to the necrotrophic fungal pathogen Botrytis cinerea and shows wild‐type sensitivity to ozone whereas jin4 is more susceptible to B. cinerea and ozone. These results indicate that the mutations in jin1 and jin4 affect different branches of the jasmonate signalling pathway. Additionally, in this combination of phenotypes, jin1 is unique among all other jasmonate‐related mutants described thus far. These data also provide support for a crosstalk between the jasmonate and salicylate pathways.