Here, we report a novel (+) ssRNA mycovirus, Phoma matteucciicola ourmia-like virus 1 (PmOLV1), isolated from Phoma matteucciicola strain LG915-1. The genome of PmOLV1 was 2603 nucleotides long and contained a single open reading frame (ORF), which could be translated into a product of RNA-dependent RNA polymerase (RdRp) by both standard and mitochondrial genetic codons. Cellular fractionation assay indicated that PmOLV1 RNAs are likely more enriched in mitochondria than in cytoplasm. Phylogenetic analysis indicated that PmOLV1 is a new member of the genus Penoulivirus (recently proposed) within the family Botourmiaviridae.

The genus Neopestalotiopsis consists of obligate parasites that cause ring spot, scab, and leaf blight diseases in higher plant species. We assembled the three complete mitogenomes for the guava fruit ring spot pathogen, Neopestalotiopsis cubana. The mitogenomes are circular, with sizes of 38,666 bp, 33,846 bp, and 32,593 bp. The comparative analyses with Pestalotiopsis fici showed that N. cubana differs greatly from it in the length of the mitogenomes and the number of introns. Moreover, they showed significant differences in the gene content and tRNAs. The two genera showed little difference in gene skewness and codon preference for core protein-coding genes (PCGs). We compared gene sequencing in the mitogenomes of the order Xylariales and found large-scale gene rearrangement events, such as gene translocations and the duplication of tRNAs. N. cubana shows a unique evolutionary position in the phylum Ascomycota constructed in phylogenetic analyses. We also found a more concentrated distribution of evolutionary pressures on the PCGs of Neopestalotiopsis in the phylum Ascomycota and that they are under little selective pressure compared to other species and are subjected to purifying selection. This study explores the evolutionary dynamics of the mitogenomes of Neopestalotiopsis and provides important support for genetic and taxonomic studies.

The pepper cultivar Yellow Lantern, one of the spiciest pepper varieties, is a local germplasm of Capsicum chinense, cultivated exclusively on Hainan Island, China. However, this variety is susceptible to viral diseases that severely affect its production. In this study, we report that pepper veinal mottle virus (PVMV) is associated with foliar chlorosis and rugosity symptoms in Yellow Lantern. To verify this correlation, we constructed a full-length cDNA clone of a PVMV isolate named HNu. The virus progeny derived from the cDNA clone replicated and moved systemically in the pepper, inducing the same symptoms as those induced by PVMV-HNu in Yellow Lantern peppers in the field. The results support that PVMV-HNu is the causal agent of foliar chlorosis and rugosity disease in Yellow Lantern. This knowledge will help in the diagnosis and prevention of disease caused by PVMV. Furthermore, the cDNA clone serves as a reverse genetic tool to study the molecular pathogenesis of PVMV.

Powdery mildew severely affects several important crops and cash plants. Disruption of mildew resistance locus O ( MLO) genes elevates resistance against powdery mildew in several plants. However, whether rubber tree ( Heveae brasiliensis) MLO proteins are linked to susceptibility remains unknown, owing to technical limitations in the genetic manipulation of this woody plant. A previous study showed that the H. brasiliensis MLO-like protein HbMLO12 demonstrates high amino acid sequence similarity with the known Arabidopsis MLO protein AtMLO12. In this study, we investigated whether HbMLO12 regulates susceptibility to powdery mildew. H. brasiliensis leaves take up exogenously synthesized double-stranded RNAs (dsRNAs), and foliar application of dsRNA homologous to HbMLO12 gene specifically induces HbMLO12 silencing in H. brasiliensis leaf tissues. Notably, HbMLO12 silencing inhibited fungal infection and elevated the immune response during interaction with the rubber tree powdery mildew fungus. Furthermore, the heterologous expression of HbMLO12 suppressed bacterial flg22– and fungal chitin–induced immune responses and enhanced bacterial infection in Arabidopsis. Our study provides evidence that HbMLO12 contributes to susceptibility to powdery mildew. [ ] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Syngonium podophyllum is a worldwide ornamental plant, particularly popular in China a garden foliage plant and houseplant. In July 2019, S. podophyllum exhibiting symptoms of a serious bacterial l...

The Artocarpus genus, belonging to the Moraceae family, exhibits various pharmacological and biological functions. However, the mitochondrial DNA (mtDNA) of Artocarpus species remains largely unexplored, which hampers our understanding of its phylogenetic classification as well as population identification. In this study, we completely sequenced and assembled the mtDNA of three Artocarpus species, including Artocarpus heterophyllus , A. heterophyllus ( R ), and A. integer . Three Artocarpus species exhibited highly similar mtDNA features, with mtDNA sizes of approximately 438,620 bp, consisting of six contigs, and included 32 different protein-coding genes (PCGs). The codon usage analysis demonstrated that Leucine and Serine were the most preferred amino acids in three Artocarpus species. Furthermore, in three Artocarpus species mt genomes, 9 homologous fragments were found to transfer from the cp genome, which contain complete psaB , psaA , ndhB and rps7 genes. Phylogenetic trees further reveal that three Artocarpus species are most closely related to Ficus carica and Morus notabilis . In summary, this study fills the gap in mitochondrial genome data within the Artocarpus genus and provides a theoretical foundation for further understanding the taxonomic classification within Artocarpus species.