of experiments complemented the spectrum of gravitational biology research
opportunities.
The following chapters summarize the current knowledge of gravity-sensing and
response mechanisms of various microorganisms and plants and especially review
the contribution of microgravity research to this field of life sciences. Gravitaxis—
the gravity-oriented swimming behavior of motile microorganisms—and the ecological importance of the capability is the topic of the third chapter. Positive and
negative gravitropism of single cells is most intensively studied and is best understood in rhizoids and protonemata of characean algae. The results of experiments in
microgravity which have contributed greatly to the characterization of the cytoskeletal basis of gravity sensing and the identification of components of the gravitropic
signaling pathway in both cell types are described in Chap. 4, while gravitropic
phenomena in fungi, mosses, and ferns, described in Chap. 5, are still more enigmatic. Gravitropism of higher plant organs is dealt with in two chapters. Whereas the
authors of Chap. 6 present a short history of research on higher plant gravitropism
and focus mainly on cellular aspects of the gravitropic signaling pathway, the
authors of Chap. 7 report on the dramatically increasing amount of molecular data
of ground and space flight experiments. Current and future results promise to unravel
the molecular basis for gravity-sensing and response mechanisms in higher plants.
The final Chap. 8 introduces several bioregenerative life support systems which
have been designed and developed by the German Space Administration and
the European Space Agency with two major goals. On the one hand, fundamental
understanding of the complex physiological interaction between different organismic components in microgravity is the prerequisite for the development of a
bioregenerative, multi-species life support system that is meant to complement the
currently used physicochemical life support systems sustaining humans on space
missions with food, oxygen, or other essential supplements, and on the other hand,
such bioregenerative systems need to be technologically optimized to be reliable and
maximal efficient to save limited resources and mass not only for long-term human
exploration missions beyond low-Earth orbit but also for ground applications in
remote places such as deserts, polar stations, and other hostile areas on Earth.
Bonn, Germany
Markus Braun
April 2018
Günter Ruyters
vi
Foreword
opportunities.
The following chapters summarize the current knowledge of gravity-sensing and
response mechanisms of various microorganisms and plants and especially review
the contribution of microgravity research to this field of life sciences. Gravitaxis—
the gravity-oriented swimming behavior of motile microorganisms—and the ecological importance of the capability is the topic of the third chapter. Positive and
negative gravitropism of single cells is most intensively studied and is best understood in rhizoids and protonemata of characean algae. The results of experiments in
microgravity which have contributed greatly to the characterization of the cytoskeletal basis of gravity sensing and the identification of components of the gravitropic
signaling pathway in both cell types are described in Chap. 4, while gravitropic
phenomena in fungi, mosses, and ferns, described in Chap. 5, are still more enigmatic. Gravitropism of higher plant organs is dealt with in two chapters. Whereas the
authors of Chap. 6 present a short history of research on higher plant gravitropism
and focus mainly on cellular aspects of the gravitropic signaling pathway, the
authors of Chap. 7 report on the dramatically increasing amount of molecular data
of ground and space flight experiments. Current and future results promise to unravel
the molecular basis for gravity-sensing and response mechanisms in higher plants.
The final Chap. 8 introduces several bioregenerative life support systems which
have been designed and developed by the German Space Administration and
the European Space Agency with two major goals. On the one hand, fundamental
understanding of the complex physiological interaction between different organismic components in microgravity is the prerequisite for the development of a
bioregenerative, multi-species life support system that is meant to complement the
currently used physicochemical life support systems sustaining humans on space
missions with food, oxygen, or other essential supplements, and on the other hand,
such bioregenerative systems need to be technologically optimized to be reliable and
maximal efficient to save limited resources and mass not only for long-term human
exploration missions beyond low-Earth orbit but also for ground applications in
remote places such as deserts, polar stations, and other hostile areas on Earth.
Bonn, Germany
Markus Braun
April 2018
Günter Ruyters
vi
Foreword