RESUMO
The Zn content in cereal seeds is an important trait for crop production as well as for human health. However, little is known about how Zn is loaded to plant seeds. Here, through a genome-wide association study (GWAS), we identify the Zn-NA (nicotianamine) transporter gene ZmYSL2 that is responsible for loading Zn to maize kernels. High promoter sequence variation in ZmYSL2 most likely drives the natural variation in Zn concentrations in maize kernels. ZmYSL2 is specifically localized on the plasma membrane facing the maternal tissue of the basal endosperm transfer cell layer (BETL) and functions in loading Zn-NA into the BETL. Overexpression of ZmYSL2 increases the Zn concentration in the kernels by 31.6%, which achieves the goal of Zn biofortification of maize. These findings resolve the mystery underlying the loading of Zn into plant seeds, providing an efficient strategy for breeding or engineering maize varieties with enriched Zn nutrition.
Assuntos
Estudo de Associação Genômica Ampla , Zea mays , Humanos , Zea mays/genética , Zea mays/metabolismo , Zinco/metabolismo , Melhoramento Vegetal , Sementes/genética , Proteínas de Membrana Transportadoras/genéticaRESUMO
Newcastle disease virus (NDV) is a contagious poultry paramyxovirus, leading to substantial economic losses to the poultry industry. Here, RNA-seq was carried out to investigate the altered expression of immune-related genes in chicken thymus within 96 h in response to NDV infection. In NDV-infected chicken thymus tissues, comparative transcriptome analysis revealed 1386 differentially expressed genes (DEGs) at 24 h with 989 up- and 397 down-regulated genes, 728 DEGs at 48 h with 567 up- and 161 down-regulated genes, 1514 DEGs at 72 h with 1016 up- and 498 down-regulated genes, and 1196 DEGs at 96 h with 522 up- and 674 down-regulated genes, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that these candidate targets mainly participate in biological processes or biochemical, metabolic and signal transduction processes. Notably, there is large enrichment in biological processes, cell components and metabolic processes, which may be related to NDV pathogenicity. In addition, the expression of five immune-related DEGs identified by RNA-seq was validated by quantitative real-time polymerase chain reaction (qRT-PCR). Our results indicated that the expression levels of AvBD5, IL16, IL22 and IL18R1 were obviously up-regulated, and Il-18 expression was also changed, but not significantly, which play key roles in the defense against NDV. Overall, we identified several candidate targets that may be involved in the regulation of NDV infection, which provide new insights into the complicated regulatory mechanisms of virus-host interactions, and explore new strategies for protecting chickens against the virus.