Dissertation

Impact of plant hormones on growth and development of actinobacteria

Author: Meij, A. van der
Date: 16 September 2020
Links: Thesis in Leiden Repository

Plants are colonized by an astounding number of microorganisms that can provide different life-support functions, including nutrient acquisition and protection against (a)biotic stresses like drought or pathogen attack Here, the diversity of bacteria living inside plant root tissue was explored with a focus on Actinobacteria, and in particular Streptomyces. Streptomycetes are filamentous bacteria that are commonly found in soil. They were brought into the laboratory for their ability to produce a large diversity of natural products, including many different antibiotics. In plant-associated environments, Streptomyces can be found in the rhizosphere, the endosphere and the phyllosphere. In these niches, they receive nutrients from the plants, feasting on various biopolymers and exudates. In return, the plant may benefit from their presence by enhanced nutrient acquisition, pathogen antagonism and induced systemic resistance To date, however, plant-Streptomyces interactions are not well understood and the mechanisms underlying plant colonization and invasion by Streptomyces remain largely elusive. Also, the chemistry of plant-Streptomyces interactions is yet underexplored, leaving us with a reservoir of untapped natural products that may contribute to solving the problem of emerging antibiotic resistance. Therefore, this research was focused on the aforementioned topics.