Speaker: Salome Prat

Time: 15:00-17:00 p.m., November 8, 2023, GMT+8

Venue: Scan the QR code to watch online


Abstract:

Plant storage organs supply a great part of the caloric intake for human and animal food needs. These specialized organs are formed by a relatively small number of plant species to which they serve as means of vegetative propagation, or as assimilates reservoir for later bolting. Depending on the species, they can differentiate from leaves (garlic and onion), specialized branches (potato tubers), the hypocotyl (ginger, horseradish), or the roots (cassava, radish, sweet potato). Swollen roots preserve most of the initial root morphology showing that sugar/starch-accumulating cells originate in roots from the vascular cambium. However, which cells originate the anatomically more complex shoot-derived organs is still under debate.  Proteins of the FLOWERING LOCUS-T family act as inducing signals for potato and onion storage transition but lack a function in storage root initiation, which has led to believe that these developmental processes are unrelated. Bulbs and tubers include an inner shoot bud, or the stolon apical meristem /first axillary buds forming the tuber “eyes”.  Activity of these meristems is arrested during storage transition, while they enter a dormancy state, to be again reactivated in the following spring and generate a new plant.  This growth cessation largely reminds that of FT-regulated winter growth cessation in perennial trees, suggesting that main role of FT paralogs in shoot-derived storage organ formation is to align this developmental transition with yearly seasons. Here, by analyzing the cell division patterns of early induced stolons we show that differentiation of starch accumulating cells is preceded by a division of the vascular cambium, consistent with a common developmental program being involved at initiation of all storage organs. Single cell RNA-seq UMAP projections revealed that storage parenchyma cells cluster together with the cambium meristem cells, in line with cambial derivative cells switching on tuberization transition their usual phloem/xylem cell specification program into a storage identity.  Pseudo-time trajectory analyses of these cells will help at identifying putative FT targets with a role at storage fate transition.

Biography:

Professor Salomé Prat  graduated in Pharmacy by the University of Barcelona and obtained a PhD degree in Plant Genetics by the same University. She worked as a post-doctoral fellow and associate researcher in the group of L. Willmitzer at the Institut für Genbiologische Forschung in Berlin (1987-92) where she was engaged in two projects aimed to the study of tissue-specific transcriptional control in potato and JA-mediated activation of defense responses against insect attack. In 1993 she was appointed as Associate Professor at the Institute of Molecular Biology of Barcelona (IBMB-CSIC) and moved to the CNB in Madrid in 2003, being promoted to Professor by 2005. As an independent group, her research has focused in photoperiodic control of storage organ formation in potato and hormonal control of cell elongation in Arabidopsis. She was awarded with the Ciutat of Barcelona Scientific Research award in 2002 and the Olchemim Scientific award in 2010. Since 2007, she is director of the Department of Plant Molecular Genetics of the CNB and was elected EMBO member in 2008.

Source: School of Advanced Agricultural Sciences