How plants grow under gravity conditions besides 1 g: perspectives from hypergravity and space experiments that employ bryophytes as a model organism
How plants grow under gravity conditions besides 1 g: perspectives from hypergravity and space experiments that employ bryophytes as a model organism
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DOI：
10.1007/s11103-021-01146-8
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发表时间：
2021-04
影响因子：
5.1
通讯作者：
A. Kume;H. Kamachi;Y. Onoda;Y. Hanba;Y. Hiwatashi;I. Karahara;T. Fujita
中科院分区：
文献类型：
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作者：
A. Kume;H. Kamachi;Y. Onoda;Y. Hanba;Y. Hiwatashi;I. Karahara;T. Fujita
植物是在地球引力的选择压力下进化和生长的。为了应对这种选择压力，植物获得了向重力性，以感受重力并改变其生长方向。此外，植物也会调整其形态发生，以应对不同的重力，这种现象称为重力阻力。然而，由于地球上普遍存在1g的重力，人们对植物中的重力阻力现象知之甚少：不仅很难在重力> 1g（超重力）的情况下长时间培养植物，而且如果没有专门的设施，也不可能在地球上创造<1g（μg，microg）的植物。尽管存在这些技术挑战，但重要的是要了解植物如何在不同的重力条件下生长，以便了解陆地植物对地球环境或外层空间探索的适应性。为了解决这个问题，我们开发了一种离心装置，用于在超重力条件下长时间培养植物，并正在国际空间站进行一个在微重力条件下种植植物的项目。我们选择的植物材料是立碗藓，它是陆地上的先驱植物之一，也是植物生物学中经常使用的模式植物。在这篇综述中，我们总结了我们的最新研究成果。关于我们正在进行的“太空苔藓”项目，在我们的地面超重力实验中，我们分析了形态和生理变化，发现叶绿体大小和光合速率的意外增加，这可能是生长增强和配子体和假根数量增加的基础。我们进一步讨论了我们在细胞水平上的方法，并比较了苔藓和被子植物的重力阻力。最后，我们强调了空间实验的优势和前景，并得出结论，与branchites的研究是有益的，全面和准确地了解植物的重力响应。
Plants have evolved and grown under the selection pressure of gravitational force at 1gon 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 1ggravitational force on Earth: not only it is difficult to culture plants at gravity > 1g(hypergravity) for a long period of time but it is also impossible to create a < 1genvironment (μg, microg) 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 1genvironment 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 μgenvironment in the International Space Station is also underway. Our plant material of choice isPhyscomitrium (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 regardingP. patensgrowth 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.