Phytopathogenic bacteria are of substantial economic importance, threatening the quantity and quality of food production. Reducing crop losses from disease epidemics caused by bacterial pathogens is critical for the supply of agricultural produce. On the other hand, colonisation of plants with beneficial bacteria can stimulate plant growth by increasing the nutrient uptake by roots or prime plants for enhanced defense against biotic and abiotic stresses, which can help to improve (or bring new approaches to) efforts to reach sustainable agriculture. Cell-to-cell communication, which is ubiquitous in all biological systems, plays a critical role in plant-bacteria interaction. Recently it has been considered that one of the significant ways to achieve cell-to-cell communication is through extracellular vesicles (EVs). These cytosol-containing membrane spheres provide selection, storage, and protection against degradation of enclosed cargoes in a highly dynamic and environmental cue-responsive manner. EVs also offer the opportunity for directed cargo delivery to dedicated recipient cells and serve as a quick adaptation strategy to react to a changing environment [1]. This project proposal aims to shed light on the vesiculation process of phytobacteria and the role of EVs in plant-bacteria interactions. The missing detailed understanding of vesiculation and EVs' properties is a critical gap in our complete knowledge of cell-to-cell communication, especially in plant-bacteria interactions. At its completion, this project will lead to new insights into the crucial tool, cell-to-cell communication, contributing to the virulence of pathogenic phytobacteria and the mechanism for how bacterial symbionts promote plant growth and fitness.

In all vertebrates, heart development is dependent on the interplay of several cell populations of distinct embryonic origin. One of these cell populations is the cardiac neural crest (CNC) which contributes to the outflow tract and spiral septum in amniotes. However, CNC cells also migrate to the ventricles and differentiate into cardiomyocytes both in zebrafish and in amniotes. Interestingly, recent results from one of the host lab have shown that CNC-derived cardiomyocytes in zebrafish have an extraordinary capacity for regeneration and that ablation of these cells blocks heart regeneration. Here, I will explore whether this regenerative capacity of cardiomyocytes is unique to zebrafish or represents an ancestral state of characters for vertebrates in general. The goal of the proposed research is to use phylogenetically important vertebrates (lamprey, sturgeon, and axolotl) to answer fundamental questions about the development of the CNC and its role in heart regeneration across vertebrates. Thus, we aim to i) examine the fate of CNC in three species; ii) determine the potential of CNC to differentiate into cardiomyocytes; iii) examine the gene expression profile of CNC cells and neural crest-derived cardiomyocytes; iv) ablate neural crest-derived cells and examine their function in heart regeneration.