2 and JASMONATE REGULATED GENE21. Furthermore, in almost all cases, the % induction of these selleck products mRNA levels by A. brassicae, three days Inhibitors,Modulators,Libraries after infection of the leaves with the Inhibitors,Modulators,Libraries spores, is com parable for WT and mutant seedlings. Therefore, it ap pears that the higher mRNA levels are mainly caused by the pathogen and not by the mutation. No significant differences could be detected for the ABA1 and ABA2 mRNA levels. The elevated phytohormone levels in unstressed cycam1 1 and cycam1 2 prompted us to investigate the re sponse of the Ca2 mutant to exogenous application of SA, methyl jasmonate and ABA. The phytoho mones were added to the MS medium in optimized con centrations. Application of SA or MeJA did not cause any difference in the growth of WT and cycam1 seedlings.

However, ABA inhibited germination and growth of cycam1 1 and cycam1 2 more than WT. At 200 nM ABA, the expansion of cycam1, but not WT cotyledons was strongly Inhibitors,Modulators,Libraries inhibited. Three weeks after treatment with 100 nm ABA, the biomass of cycam1 seedlings was less than half of the biomasses of WT seedlings. Thus, the elevated ABA level already present in the mutants in addition to the exogenous application of ABA is deleteri ous for the mutants. It is interesting to note that also in the presence of ABA, no Ca2 response was observed in the cycam1 mutant in response to the fungal stimuli. A. brassicae affects camalexin and glucosinolate levels Camalexin and glucosinolates are major sulphur contain ing secondary metabolites involved in plant defense in Ara bidopsis. A.

brassicae infection induced both camalexin and indolic glucosinolates and their biosynthesis genes in the WT and mutant. The induction of the aliphatic glucosinolates 3 methylthiobutyl GLS, 4 methyl sulfinylbutyl GLS, 4 methylthiobutyl GLS and 8 methylsulfinyl octyl GLS was not significantly different between WT and mutant seedlings, while the aGLS 5 methylsulfinylpentyl Inhibitors,Modulators,Libraries GLS and 7 methylsulfinylheptyl GLS levels were higher in the WT than the mutants. The expression of MYB28, MYB29 and BCAT4 which are involved in aGLS biosynthesis were also upregulated in the WT and not in the mutant after A. brassicae infection. This shows that aGLS biosynthesis is less effi ciently induced in cycam1. Discussion Exudate preparations from A. brassicae, R. solani, P. para sitica, and A. tumefaciens induce cyt elevation in Ara bidopsis roots as monitored with the bioluminescent Ca2 binding protein aequorin.

Characterization of the Ca2 signatures induced by these stimuli Inhibitors,Modulators,Libraries demonstrates that they resemble those described for many MAMPs from various plant spe cies B glucan from P. sojae in soybean cell cultures, pep 13 from Phytophthora sojae in parsley cell cultures, harpin from Pseudomonas syringae pv. phaseolina in tobacco, a yeast elicitor and chitosan in Arabidospsis, cryptogein from P. selleckchem cryptogea and oligosaccharides in tobacco cell cultures, pep 25 from P.