In this issue of Applied and Environmental Microbiology (AEM), we publish a paper by Fenghuan Yang, Fang Tian, Huamin Chen, William Hutchins, Ching-Hong Yang, and Chenyang He from the State Key Laboratory for Biology of Plant Diseases and Insect Pests at the Chinese Academy of Agricultural Sciences and the Department of Biological Sciences at the University of Wisconsin—Milwaukee, reporting on ...

Many harpins have been found in plant pathogen bacteria that can elicit disease and insect resistance in plants, and promote plant growth. In this work, we overexpressed and purified Xanthomonas oryzae pv. oryzae harpin, harpin(Xoo), in Escherichia coli BL21/pGEX-hpa1. Harpin(Xoo) was fused to the C-terminus of glutathione S-transferase (GST) and purified using the Bulk GST purification module ...

Mechanisms Underlying Broad Spectrum Resistance Genome-wide interactions between Xanthomonas oryzae pv. oryzae (Xoo) and rice resulting from a broad-spectrum hypersensitive reaction (BSHR) mediated by a new rice R gene, Xa39, were investigated by comparative dynamic transcriptomic profiles in the incompatible and compatible interactions using three related rice lines and a highly virulent Xoo i...

Disease resistance mediated by the resistance gene Xa21 is developmentally controlled in rice. We examined the relationship between Pathogenesis Related (PR) defense gene expression and Xa21-mediated developmental disease resistance induced by Xanthomonas oryzae pv. oryzae (Xoo). OsPR1a, OsPR1b, and OsPR1c genes were cloned and their induction was analyzed, in addition to the OsPR10a gene, at t...

Pattern recognition receptors (PRRs) play an important role in detecting invading pathogens and mounting a robust defense response to restrict infection. In rice, one of the best characterized PRRs is XA21, a leucine rich repeat receptor-like kinase that confers broad-spectrum resistance to multiple strains of the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo). In 2009 we reported that ...

Rice leaf blight, which is caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), results in huge losses in grain yield. Here, we show that Xoo-induced rice leaf blight is effectively controlled by niclosamide, an oral antihelminthic drug and molluscicide, which also functions as an anti-tumor agent. Niclosamide directly inhibited the growth of the three Xoo strains PXO99, 10208 ...

A bacterial tyrosine sulfotransferase, RaxST, is required for activation of rice XA21-mediated immunity, and it catalyzes sulfation of tyrosine residues of Omp1X and RaxX in Xanthomonas oryzae pv. oryzae, a causal agent of bacterial blight in rice. Although RaxST is biochemically well-characterized, biological functions of tyrosine sulfation have not been fully elucidated. We compared protein e...

Somatic embryogenesis receptor kinases (SERKs) are leucine-rich repeat (LRR)-containing integral membrane receptors that are involved in the regulation of development and immune responses in plants. It has recently been shown that rice SERK2 (OsSERK2) is essential for XA21-mediated resistance to the pathogen Xanthomonas oryzae pv. oryzae. OsSERK2 is also required for the BRI1-mediated, FLS2-med...