Reproductive development in passion fruit: a transcriptomic approach to phase transition

Author(s)

Scott Carrara

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2022-04-12

Examining board members

Marcelo Carnier Dornelas; Sara Adrián López de Andrade; Melina Cristina Mancini

• Advisor: Marcelo Carnier Dornelas

Abstract

The passion fruit (Passiflora edulis var. flavicarpa) belongs to the Passiflora genus, which consists of about 600 species, distributed mainly in the American continent, most of them originating in South America. The Passiflora genus is an excellent model for phase transition studies, due to evident morphological differences that allow to separate the plant development into three distinct phases: juvenile, vegetative mature and reproductive mature. In almost all species of the genus Passiflora, plants in the juvenile stage produce leaves with a morphology that it different from the leaf morphology found in mature stage and do not produce tendrils. Plants in the mature vegetative stage produce tendrils in the leaf axils and, in the mature reproductive stage, they produce tendrils and flowers from the same axillary meristems. The molecular mechanisms that define these structures of common origin, but with totally different identities, are not defined. The hypothesis of this work is that conserved molecular mechanisms involved in the modulation of meristematic activity, or in the induction of de novo meristematic activity, may have an important role in the phase transition. Using transcriptomics and gene structure analyses, we sought to (a) identify which genes are differentially expressed in the apexes throughout the different stages of development, (b) identify and characterize the genes of the TCP family in Passiflora edulis, whose activity in controlling meristem regulation is already well known in other species, such as Arabidopsis thaliana. From the RNA-Seq analysis, 655 transcripts were found differentially expressed throughout development, of which 6 were members of the TCP family. Using the genome of Passiflora organensis, a species closely related to P. edulis, 27 putative genes of the TCP family were found, which had their gene structure identified. and together with the AtTCP sequences, a phylogenetic tree was built that allowed the establishment of nomenclature and orthology. For part of the genes, a synteny analysis was also performed using genes from Populus trichocharpa and Vitis vinifera to allow a better analysis of the evolution of part of these genes, since for most of the genes it was not possible to perform the synteny using A. thaliana, due to the phylogenetic distance. These results corroborate the initial hypothesis, since from the RNA-Seq results, differentially expressed genes were found throughout development that are orthologous to genes already known in the literature. It is expected that these results will bring valuable contributions to future development studies and, finally, to the establishment of molecular mechanisms that regulate plant architecture (AU)

• FAPESP's process: 18/24827-5 - Reproductive development in passion fruit: a transcriptomic approach to phase transition
• Grantee: Scott Carrara
• Support Opportunities: Scholarships in Brazil - Master