1) 25/45 736 Hrop2 leucine-rich-repeat type III effector protein (GALA5) [Ralstonia solanacearum PSI07] (YP_003752484.1) 32/46 641 The T3SS putative effectors were identified by BlastX and EffectiveT3 (http://www.effectors.org/) (Arnold et al., 2009). The proteins HropAN1 (H. rubrisubalbicans outer protein), HropAV1 and HropF1 are similar in sequence to
HopAN1 (Burkholderia sp.), HopAV1 (Ralstonia solanacearum) and XopF1 (Xanthomonas oryzae), respectively. Hrop1 is homologous to a type III effector protein from Ralstonia solanacearum PF-6463922 price MolK2. Hrop2 belongs to the leucine-rich repeats (LRRs) ribonuclease inhibitor (RI)-like subfamily [32]. The genes encoding HropAV1 and Hrop1 immediately upstream of the hpaB1 gene, and outside the main T3SS gene cluster. The H. rubrisubalbicans HrpB protein is homologous (identity 27%/similarity 48%) to the Pseudomonas syringae HrpB protein that is secreted and contributes to elicitation of the hypersensitive response in Nicotiana tabacum and Nicotiana benthamiana [33]. This similarity Fludarabine in vitro suggests that H. rubrisubalbicans HrpB is a candidate for a
secreted protein. H. rubrisubalbicans hrpE and hrcN genes are essential for the development of mottled stripe disease in sugarcane variety B-4362. To investigate the contribution of T3SS to the plant-bacterial interaction process we Liothyronine Sodium generated the mutants TSN and TSE of H. rubrisubalbicans carrying Tn5 insertions in the hrcN and hrpE genes, respectively. H. rubrisubalbicans HrcN protein contains 442 aminoacids and is homologous to T3SS-associated ATPases. The H. rubrisulbalbicans HrpE protein contains 202 aminoacids and belongs to the YscL/FliH family of cytoplasmic proteins [34]. The wild type M1 and the mutant strains TSN and TSE were inoculated into the susceptible sugarcane variety B-4362. After 15 days, strain M1 caused typical symptoms
of mottled stripe disease (mottled background with red stripes and red patches) and well-developed signs of necrosis in leaves invaded by bacteria (Figure 4a). In contrast, the mutants TSN and TSE did not elicit disease symptoms (Figure 4b,c). These results indicate that hrpE and hrcN gene products are required for the expression of visible symptoms of mottled stripe disease in sugarcane leaves variety B-4362. Figure 4 Inoculation of sugarcane variety B-4362 with wild type and hrpE mutant strains of H. rubrisubalbicans. 120 days after find more germination, 5 sugarcane plants variety B-4362 were inoculated with 10 mM of MgSO4 (a), H. rubrisubalbicans M1 (0.5 – 1.0×108 cells) (b) and H. rubrisubalbicans TSE (0.5 – 1.0×108 cells) (c). The photos were taken 15 days after inoculation (135 days after germination). The arrows indicate bacterial inoculation site and symptoms of the mottled stripe disease (b). The scale bars are shown (1 cm).