We also observed that the P. ultimum genome encodes candidate GH13 a amylases, GH15 glucoamy lase and a GH32 invertase, suggesting that plant starch and sucrose are targeted. The growth data confirm these observations, with excellent Y-27632 msds growth on soluble starch and sucrose. The CAZy database also contains enzymes involved in fungal cell wall synthesis and remodeling. Cell walls of oomycetes differ markedly from cell walls of Fungi and consist mainly of glucans containing b 1,3 and b 1,6 linkages and cellulose. The P. ultimum genome encodes four cellulose synthases closely related to their orthologs described for Ph. infestans.

The genome also Inhibitors,Modulators,Libraries specifies a large number of enzyme activities that may be involved in the metabolism of b 1,3 and b 1,6 glucans, as well as a large set of can didate b 1,3 glucan synthases likely involved in Inhibitors,Modulators,Libraries synthesis of cell wall b glucans and in the metabolism of mycola minaran, the main carbon storage compound in Phy tophthora and Pythium Inhibitors,Modulators,Libraries spp. Reponses to fungicide Metalaxyl and its enantiopure R form mefenoxam have been used widely since the 1980s for the control of plant diseases caused by oomycetes. The main mechanism of action of this fungicide is selective inhibi tion of ribosomal RNA synthesis by interfering with the activity of the RNA polymerase I complex. P. ulti mum DAOM BR144 is sensitive to mefenoxam at con centrations higher than 1 ul l and 45 genes were expressed five fold or more when P. ulti mum was exposed to it. Active ABC pump efflux systems are important factors for drug and antifungal resistance in Fungi and oomy cetes.

Although the substrates transported Inhibitors,Modulators,Libraries by ABC proteins cannot be predicted on the basis of sequence homology, it is clear that these membrane transporters play a key role in the adaptation to envir onmental change. Three pleiotropic Inhibitors,Modulators,Libraries drug resistance pro teins were strongly up regulated in response to mefenoxam. These genes arose from a tandem duplication event but remain so similar that it is possible that only one of these genes is actually up regulated under these conditions due to our inability to uniquely map mRNA seq reads when there are highly similar paralogs. A fourth gene and a member of the multidrug resistance associated family was also up regu lated more than nine fold. Notably, the ABC transpor ters in P. ultimum that were up regulated are distinct from those that were up regulated in Ph.

infestans in response to metalaxyl, indicating that a unique set of ABC transporters may be involved in the response to the fungicide in P. ultimum. Three genes coding for E3 ubiquitin protein ligase were more than 18 fold up regulated in response to mefenoxam compared to the control, but not in the other tested conditions. Ubiqui tin proteasome further info mediated proteolysis is activated in response to stress such as nutrient limitation, heat shock, and exposure to heavy metals that may cause formation of damaged, denatured, or misfolded proteins.