TY - JOUR
T1 - How plants grow under gravity conditions besides 1 g
T2 - perspectives from hypergravity and space experiments that employ bryophytes as a model organism
AU - Kume, Atsushi
AU - Kamachi, Hiroyuki
AU - Onoda, Yusuke
AU - Hanba, Yuko T.
AU - Hiwatashi, Yuji
AU - Karahara, Ichirou
AU - Fujita, Tomomichi
N1 - Funding Information:
We would like to thank Dr. Ooi-Kock Teh (Hokkaido University) for carefully reading this manuscript. We are also grateful to Kaoru L. Tsuji (Miyagi University) and Yuki Yamashita (Hokkaido University) for providing the images shown in Figs. c and f, respectively. Some of the research introduced here has been carried out as part of the “Environmental response and utilization of mosses in space -Space Moss-” project supported by the “Kibo” utilization feasibility study of JAXA (Japan Aerospace Exploration Agency). The research was also supported by Miyagi University designated research fund (special promotion research). From the inception of the “Space Moss” working group of the Space Environment Utilization Science Committee, great support has been received from many parties, including JAXA, NASA (National Aeronautics and Space Administration), and students belonging to the authors’ laboratories. The ISS crews made great contributions by performing the experiments in space.
Funding Information:
We would like to thank Dr. Ooi-Kock Teh (Hokkaido University) for carefully reading this manuscript. We are also grateful to Kaoru L. Tsuji (Miyagi University) and Yuki Yamashita (Hokkaido University) for providing the images shown in Figs. 4 c and 5 f, respectively. Some of the research introduced here has been carried out as part of the ?Environmental response and utilization of mosses in space -Space Moss-? project supported by the ?Kibo? utilization feasibility study of JAXA (Japan Aerospace Exploration Agency). The research was also supported by Miyagi University designated research fund (special promotion research). From the inception of the ?Space Moss? working group of the Space Environment Utilization Science Committee, great support has been received from many parties, including JAXA, NASA (National Aeronautics and Space Administration), and students belonging to the authors? laboratories. The ISS crews made great contributions by performing the experiments in space.
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature B.V.
PY - 2021/11
Y1 - 2021/11
N2 - Plants have evolved and grown under the selection pressure of gravitational force at 1 g on Earth. In response to this selection pressure, plants have acquired gravitropism to sense gravity and change their growth direction. In addition, plants also adjust their morphogenesis in response to different gravitational forces in a phenomenon known as gravity resistance. However, the gravity resistance phenomenon in plants is poorly understood due to the prevalence of 1 g gravitational force on Earth: not only it is difficult to culture plants at gravity > 1 g(hypergravity) for a long period of time but it is also impossible to create a < 1 genvironment (μg, micro g) on Earth without specialized facilities. Despite these technical challenges, it is important to understand how plants grow in different gravity conditions in order to understand land plant adaptation to the 1 g environment or for outer space exploration. To address this, we have developed a centrifugal device for a prolonged duration of plant culture in hypergravity conditions, and a project to grow plants under the μg environment in the International Space Station is also underway. Our plant material of choice is Physcomitrium (Physcomitrella) patens, one of the pioneer plants on land and a model bryophyte often used in plant biology. In this review, we summarize our latest findings regarding P. patens growth response to hypergravity, with reference to our on-going “Space moss” project. In our ground-based hypergravity experiments, we analyzed the morphological and physiological changes and found unexpected increments of chloroplast size and photosynthesis rate, which might underlie the enhancement of growth and increase in the number of gametophores and rhizoids. We further discussed our approaches at the cellular level and compare the gravity resistance in mosses and that in angiosperms. Finally, we highlight the advantages and perspectives from the space experiments and conclude that research with bryophytes is beneficial to comprehensively and precisely understand gravitational responses in plants.
AB - Plants have evolved and grown under the selection pressure of gravitational force at 1 g on Earth. In response to this selection pressure, plants have acquired gravitropism to sense gravity and change their growth direction. In addition, plants also adjust their morphogenesis in response to different gravitational forces in a phenomenon known as gravity resistance. However, the gravity resistance phenomenon in plants is poorly understood due to the prevalence of 1 g gravitational force on Earth: not only it is difficult to culture plants at gravity > 1 g(hypergravity) for a long period of time but it is also impossible to create a < 1 genvironment (μg, micro g) on Earth without specialized facilities. Despite these technical challenges, it is important to understand how plants grow in different gravity conditions in order to understand land plant adaptation to the 1 g environment or for outer space exploration. To address this, we have developed a centrifugal device for a prolonged duration of plant culture in hypergravity conditions, and a project to grow plants under the μg environment in the International Space Station is also underway. Our plant material of choice is Physcomitrium (Physcomitrella) patens, one of the pioneer plants on land and a model bryophyte often used in plant biology. In this review, we summarize our latest findings regarding P. patens growth response to hypergravity, with reference to our on-going “Space moss” project. In our ground-based hypergravity experiments, we analyzed the morphological and physiological changes and found unexpected increments of chloroplast size and photosynthesis rate, which might underlie the enhancement of growth and increase in the number of gametophores and rhizoids. We further discussed our approaches at the cellular level and compare the gravity resistance in mosses and that in angiosperms. Finally, we highlight the advantages and perspectives from the space experiments and conclude that research with bryophytes is beneficial to comprehensively and precisely understand gravitational responses in plants.
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U2 - 10.1007/s11103-021-01146-8
DO - 10.1007/s11103-021-01146-8
M3 - Review article
C2 - 33852087
AN - SCOPUS:85104355945
VL - 107
SP - 279
EP - 291
JO - Plant Molecular Biology
JF - Plant Molecular Biology
SN - 0167-4412
IS - 4-5
ER -