Joshua Vandenbrink

1. Introduction Research of plant growth in space has been conducted since the beginning of manned space flight, and the performance of higher plants in microgravity has been obtained from a diverse variety of plants as well as organ, tissue, cell- and protoplast cultures [1,2]. Early investigations established that plants grow successfully in space when physical constraints such as lack of buoyancy are properly mitigated [3] and oxygen [4,5] and nutrient requirements are met [6].

1 Introduction The root is an essential organ for absorbing water and nutrients from the soil in terrestrial plants. Root system architecture is vital for the efficient acquisition of water and nutrients that are unevenly distributed throughout the ground. The root growth angle, which affects the root system architecture, is controlled by root gravitropism.