Project description:To verify the pathogenicity of Lecanicillium psalliotae invasive pathogens on tsearch leaves, Lecanicillium psalliotae was identified by isolation and purification. sweet orange leaves were infested with it. The results of the experiments showed that 15 days after Lecanicillium psalliotae infested the leaves of sweet orange, yellow spots grew around the pores and irregular yellow spots appeared on both sides of the leaf veins. This was highly similar to the disease in the field, suggesting that Lecanicillium psalliotae is the causal agent of the yellow spots on sweet orange leaves that cause the leaves to wilt and fall off. In previous studies, Verticillium cutaneum was mainly identified as a biological control agent and a suspected pathogen. In this study, the pathogenicity of Verticillium cutaneum was verified for the first time as a causal agent of leaf spot disease of plants.
Project description:Northern corn leaf blight (NLB), caused by the fungal pathogen Exserohilum turcicum, results significant yield reductions in infected corn. The first major locus conferring resistance to E. turcicum race 0, Ht1, was identified over 50 years ago, but despite widespread deployment the underlying gene has remained unknown. We employed map-based cloning to identify the Ht1 causal gene, which was found to be a coiled-coil nucleotide-binding, leucine-rich repeat (NLR) gene, termed PH4GP-Ht1. Transgenic testing confirmed that addition of the native PH4GP-Ht1 sequence to the susceptible maize variety PH184C resulted in resistance to E. turcicum race 0. A survey of the maize NAM genomes revealed that susceptible Ht1 alleles had very low to no expression, but overexpression of the susceptible B73 allele did not result in resistant plants, indicating that relatively minor protein sequence variations may underlie the resistance phenotype. Modeling of the PH4GP-Ht1 protein indicated that it has structural homology to the Arabidopsis NLR resistance gene ZAR1, and likely forms a similar homo-pentamer structure following activation. RNA-seq data from an infection time course revealed that one week after inoculation there was a threefold reduction in fungal biomass and a dramatic increase in DEGs when comparing mock to inoculated PH4GP-Ht1 transgenic plants and null plants. These results demonstrate that the NLR PH4GP-Ht1 is the causal gene underlying the NLB resistance phenotype of Ht1.
Project description:We performed RNA-Seq of leaves of Oryza sativa L. ssp. japonica cv. Nipponbare 48 hours after inoculation with Xanthomonas oryzae pv. oryzicola strain BLS354, the causal agent of bacterial leaf streak. Results provide insight into the molecular basis of bacterial leaf streak, particularly the role of transcription activator-like effectors in the disease.
Project description:We performed RNA-Seq of leaves of Oryza sativa L. ssp. japonica cv. Nipponbare 48 hours after inoculation with 10 geographically diverse strains of Xanthomonas oryzae pv. oryzicola, the causal agent of bacterial leaf streak. Results provide insight into the molecular basis of bacterial leaf streak, particularly the role of transcription activator-like effectors in the disease.
