Salinity is one of the most serious threats to sustainable agriculture. The Salt Overly Sensitive (SOS) signaling pathway plays an important role in salinity tolerance in plants, and the SOS2 gene plays a critical role in this pathway. Mulberry not only has important economic value but also is an important ecological tree species; however, the roles of the SOS2 gene associated with salt stress have not been reported in mulberry. To gain insight into the response of mulberry to salt stress, SOS2 (designated MulSOS2) was cloned from mulberry (Morus atropurpurea Roxb), and sequence analysis of the amino acids of MulSOS2 showed that it shares some conserved domains with its homologs from other plant species. Our data showed that the MulSOS2 gene was expressed at different levels in different tissues of mulberry, and its expression was induced substantially not only by NaCl but also by ABA. In addition, MulSOS2 was exogenously expressed in Arabidopsis, and the results showed that under salt stress, transgenic MulSOS2 plants accumulated more proline and less malondialdehyde than the wild-type plants and exhibited increased tolerance to salt stress. Moreover, the MulSOS2 gene was transiently overexpressed in mulberry leaves and stably overexpressed in the hairy roots, and similar results were obtained for resistance to salt stress in transgenic mulberry plants. Taken together, the results of this study are helpful to further explore the function of the MulSOS2 gene, which provides a valuable gene for the genetic breeding of salt tolerance in mulberry.

Cronartium ribicola is a globally distributed fungal pathogen that infects Pinus armandii Franch., causing widespread tree mortality. In this study, we report a chromosomal-level genome assembly of C. ribicola LQ (262.51 Mb, N50 = 15.4 Mb, GC content = 38.4%) using integrated Illumina short-read, PacBio long-read, and Hi-C sequencing technologies. Ultimately, a total of 94.83% of the assembled sequences were anchored onto 17 pseudo-chromosomes. Genome annotation predicted 10,222 protein-coding genes, and repetitive sequences accounted for 91.67% of the genome. Benchmarking Universal Single-Copy Ortholog (BUSCO) analysis demonstrated 94.03% genome completeness, with functional annotations covering 88.32% of the genes. A total of 352 carbohydrate-active enzyme (CAZyme) genes, predominantly glycoside hydrolases (45.17%), and 8 secondary metabolite biosynthetic gene clusters were identified, indicating strong host tissue degradation capability and diverse virulence factors. Overall, this study provides valuable genomic resources for dissecting the pathogenicity, host interaction mechanisms, and resistance gene discovery of C. ribicola and establishes a foundation for developing virulence-targeted disease control strategies.