Browsing by Author "Larama, Giovanni"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Genomic structure of yellow lupin (Lupinus luteus): genome organization, evolution, gene family expansion, metabolites and protein synthesis
    (2025) Martinez-Hernandez, J. E.; Salvo-Garrido, Haroldo; Levicoy, Daniela; Caligari, Peter D. S.; Rupayán, Annally; Moyano Yugovic, Tomás Custodio; Carrasco, Makarena; Hernandez, Sebastián; Armijo-Godoy, Grace; Westermeyer, Fernando; Larama, Giovanni
    Yellow lupin (Lupinus luteus) gives valuable high-quality protein and has good sustainability due to its ability in nitrogen fixation and exudation of organic acids, which reduces the need for chemical-based phosphate fertilization in acid soils. However, the crop needs further improvements to contribute in a major way to sustainable agriculture and food security. In this study, we present the first chromosome-level genome assembly of L. luteus. The results provide insights into its genomic organization, evolution, and functional attributes. Using integrated genomic approaches, we unveil the genetic bases governing its adaptive responses to environmental stress, delineating the intricate interplay among alkaloid biosynthesis, mechanisms of pathogen resistance, and secondary metabolite transporters. Our comparative genomic analysis of closely related species highlights recent speciation events within the Lupinus genus, exposing extensive synteny preservation alongside notable structural alterations, particularly chromosome translocations. Remarkable expansions of gene families implicated in terpene metabolism, stress responses, and conglutin proteins were identified, elucidating the genetic basis of L. luteus’ superior nutritional profile and defensive capabilities. Additionally, a diverse array of disease resistance-related (R) genes was uncovered, alongside the characterization of pivotal enzymes governing quinolizidine alkaloid biosynthesis, thus shedding light on the molecular mechanisms underlying “bitterness” in lupin seeds. This comprehensive genomic analysis serves as a valuable resource to improve this species in terms of resilience, yield, and seed protein levels to contribute to food and feed to face the worldwide challenge of sustainable agriculture and food security.
  • No Thumbnail Available
    Item
    Tree Cover Species Modify the Diversity of Rhizosphere-Associated Microorganisms in Nothofagus obliqua (Mirb.) Oerst Temperate Forests in South-Central Chile
    (2022) Almonacid-Munoz, Leonardo; Herrera, Hector; Fuentes-Ramirez, Andres; Vargas-Gaete, Rodrigo; Larama, Giovanni; Jara, Ronald; Fernandez-Urrutia, Camila; da Silva Valadares, Rafael Borges
    Chilean native forests have been subjected to several types of disturbances, with one of them being the replacement by exotic species. Pinus radiata D. Don is a widespread exotic tree that forms extensive plantations in southern Chile. It covers extended areas, affecting the landscape, biodiversity, and ecosystem services associated with native forest ecosystems. Although advances in assessing the impact of exotic plant species have been conducted, few studies have focused on the alteration of soil microorganisms. This study aimed to characterize the rhizosphere bacterial and fungal communities associated with the tree species Nothofagus obliqua inside a native forest stand and within a P. radiata plantation growing nearby. We used a 16S rRNA gene and ITS region metabarcoding approach. Using bioinformatics, diversity indices, relative abundance, preferential taxa, and predicted functions and guilds were estimated. The beta-diversity analysis showed that both factors, the type of soil (rhizosphere or bulk soil) and the type of site (native forest or P. radiata plantation), were significant, with the site explaining most of the variation among bacterial and fungal communities. Proteobacteria and Basidiomycota were the most abundant bacterial and fungal phyla in both types of soil and sites. Similarly, bacteria showed similar abundant taxa at the family level, independent of the soil type or the site. The main fungal taxa associated with native forests were Tricholomataceae and Cantharellales, whereas in P. radiata plantations, Russulaceae and Hyaloscyphaceae were the most abundant families. The main bacteria functional groups were chemoheterotrophy and aerobic chemoheterotrophy, without significant differences between the type of soil or sites. Overall, these results demonstrate that the composition and diversity of bacterial and fungal communities associated with native N. obliqua forest are influenced by the surrounding forest, and mainly depend on the site's characteristics, such as the lignin-rich wood source. These results improve our understanding of the impact of native forest replacement on soil microbial communities, which can alter microbial-related soil ecosystem services.