Plant propagation systems in Araucaria angustifolia: physiological, biochemical and molecular approaches to optimize biotechnological strategies for the use and conservation of the species.

• Grant number: 25/01112-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2025
• End date: April 30, 2028
• Field of knowledge: Biological Sciences - Botany - Applied Botany
• Principal Investigator: Eny Iochevet Segal Floh
• Grantee: Eny Iochevet Segal Floh
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Ivar Wendling ; juliana degenhardt goldbach ; Leandro Francisco de Oliveira

Abstract

Araucaria angustifolia is a native Brazilian tree species of great economic, social and environmental importance and critically endangered. The recalcitrance of its seeds and the long period for pine seed production have been restrictive factors for the use of effective methods for its propagation and conservation. In this scenario, although with limitations in reaching viable levels as propagation methods, grafting and somatic embryogenesis stand out as promising techniques for the multiplication of genotypes of interest and for the early production of pine seeds. Difficulties related to exercise include the plagiotropic growth habit and the morphology of the grafted plants that remain after exercise, compromising the plant's architecture and its tipping over. Additionally, the mechanisms involved in the reversion of graft from branch (plagiotropic) to trunk (orthotropic) are still completely unknown, as well as which endogenous information is already pre-determined in the two types of epicormic buds (trunk and branch), and the its performance so that these habits remain while the exercise is developed. Regarding somatic embryogenesis, the lack of an efficient protocol for the development of somatic embryos to the mature stage is an impediment to the use of the technique on a large scale. In this case, several advances were obtained in the characterization of responsive lineages for embryogenesis, in studies carried out at BIOCEL/USP, allowing large quantities of globular somatic embryos to be obtained, but which do not progress to later stages. Additionally, from omics platforms, relevant information was obtained regarding the involvement of genes and metabolites during the formation of the A. angustifolia embryo. In this context, the present project aims to: 1) grafting: elucidate the physiological, biochemical and molecular bases associated with determining the development of grafts in trunk and branch; 2) somatic embryogenesis: obtaining lineages responsive to somatic embryogenesis, and transition of the somatic embryo from the globular to the cotyledonary stage in materials from clonal plantations of high productivity and uniformity. The results to be obtained aim to obtain scientific and technological advances in existing strategies for vegetative propagation that can be used for production in large quantities and high quality, and can simultaneously provide products for commercial and conservation purposes of A. angustifolia. (AU)