Background Magnaporthe oryzae, the rice blast fungus, might secrete certain proteins related to plant-fungal pathogen interactions.Methodology/Principal FindingsIn this study, we report the purification, characterization, and gene cloning of a novel hypersensitive response-inducing protein elicitor (MoHrip1) secreted by M. oryzae. The protein fraction was purified and identified by de novo sequencing, and the sequence matched the genomic sequence of a putative protein from M. oryzae strain 70-15 (GenBank accession No. XP_366602.1). The elicitor-encoding gene mohrip1 was isolated; it consisted of a 429 bp cDNA, which encodes a polypeptide of 142 amino acids with a molecular weight of 14.322 kDa and a pI of 4.53. The deduced protein, MoHrip1, was expressed in E. coli. And the expression protein collected from bacterium also forms necrotic lesions in tobacco. MoHrip1 could induce the early events of the defense response, including hydrogen peroxide production, callose deposition, and alkalization of the extracellular medium, in tobacco. Moreover, MoHrip1-treated rice seedlings possessed significantly enhanced systemic resistance to M. oryzae compared to the control seedlings. The real-time PCR results indicated that the expression of some pathogenesis-related genes and genes involved in signal transduction could also be induced by MoHrip1.Conclusion/SignificanceThe results demonstrate that MoHrip1 triggers defense responses in rice and could be used for controlling rice blast disease.

Traditional photodynamic phototherapy is not efficient for anticancer treatment because solid tumors have a hypoxic microenvironment. The development of photoactivated chemotherapy based on photoresponsive polymers that can be activated by light in the "therapeutic window" would enable new approaches for basic research and allow for anticancer phototherapy in hypoxic conditions. This work synthesizes a novel Ru-containing block copolymer for photoactivated chemotherapy in hypoxic tumor environment. The polymer has a hydrophilic poly(ethylene glycol) block and a hydrophobic Ru-containing block, which contains red-light-cleavable (650-680 nm) drug-Ru complex conjugates. The block copolymer self-assembles into micelles, which can be efficiently taken up by cancer cells. Red light induces release of the drug-Ru complex conjugates from the micelles and this process is oxygen independent. The released conjugates inhibit tumor cell growth even in hypoxic tumor environment. Furthermore, the Ru-containing polymer for photoactivated chemotherapy in a tumor-bearing mouse model is applied. Photoactivated chemotherapy of the polymer micelles demonstrates efficient tumor growth inhibition. In addition, the polymer micelles do not cause any toxic side effects to mice during the treatment, demonstrating good biocompatibility of the system to the blood and healthy tissues. The novel red-light-responsive Ru-containing polymer provides a new platform for phototherapy against hypoxic tumors.

N-methylated adenine (mA) is the most frequent posttranscriptional modification in eukaryotic mRNA. Turnover of RNA generates N-methylated AMP (N-mAMP), which has an unclear metabolic fate. We show that and human cells require an N-mAMP deaminase (ADAL, renamed MAPDA) to catabolize N-mAMP to inosine monophosphate in vivo by hydrolytically removing the aminomethyl group. A phylogenetic, structural, and biochemical analysis revealed that many fungi partially or fully lack MAPDA, which coincides with a minor role of NA-RNA methylation in these organisms. MAPDA likely protects RNA from mA misincorporation. This is required because eukaryotic RNA polymerase can use N-mATP as a substrate. Upon abrogation of , root growth is slightly reduced, and the N-methyladenosine, N-mAMP, and N-mATP concentrations are increased in Arabidopsis. Although this will potentially lead to mA misincorporation into RNA, we show that the frequency is too low to be reliably detected in vivo. Since N-mAMP was severalfold more abundant than N-mATP in mutants, we speculate that additional molecular filters suppress the generation of N-mATP. Enzyme kinetic data indicate that adenylate kinases represent such filters being highly selective for AMP versus N-mAMP phosphorylation. We conclude that a multilayer molecular protection system is in place preventing N-mAMP accumulation and salvage.

Our studies indicate a potential important elicitor candidate which can aid in the fight against a worldwide disease, rice blast. In this study, we report the purification, identification, characterization, and gene cloning of a novel hypersensitive response-inducing protein elicitor (MoHrip2) secreted from an important pathogenic fungus, Magnaporthe oryzae. The protein fraction was isolated from the culture filtrate of M. oryzae and identified by de novo sequencing. The elicitor-encoding gene mohrip2 was cloned following sequence comparison and PCR amplification. This 459-bp gene encodes a 152-residue polypeptide that contains an 18-residue signal peptide and exhibits a pI of 4.72 and an apparent molecular mass of 16 kDa. The hypothetical protein, MoHrip2, was expressed in Escherichia coli, and both the recombinant and the endogenous protein caused necrotic lesions in tobacco leaves. In addition to phenolic compound deposition and alkalization of the extracellular medium, MoHrip2 also induced hydrogen peroxide production and nitric oxide accumulation in tobacco cells. Moreover, rice seedlings treated with MoHrip2 exhibited pronounced resistance to M. oryzae compared with control seedlings.