Cell wall thickness and composition are related to photosynthesis in Antarctic mosses.
Cell wall thickness and composition are related to photosynthesis in Antarctic mosses.
复制标题
南极苔藓的细胞壁厚度和成分与光合作用有关。
DOI：
10.1111/ppl.13533
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发表时间：
2021
影响因子：
6.4
通讯作者：
J. Flexas
中科院分区：
文献类型：
--
作者：
Margalida Roig;C. Douthe;J. Bota;J. Flexas
细胞壁厚度（Tcw）被认为是陆地植物的一个重要解剖学性状，它可以通过植物的生殖发育来决定光合作用，而植物类群中的细胞壁最厚，光合速率最低。此外，最近有人提出，细胞壁组成可能有可能影响厚度和叶肉电导率（gm），代表一种新的性状，最终可能影响光合作用。然而，只有少数的研究在种子植物已经证明了这个问题。为了探讨细胞壁组成的作用，在确定TCW和GM的苔藓，我们测试了6种生长在南极洲的野外条件下。我们进行了气体交换和叶绿素荧光测量、解剖学表征和细胞壁主要成分的定量分析（即，纤维素、半纤维素和果胶）。我们发现，光合速率不同的物种之间，他们也提出了解剖特征和细胞壁组成的差异。虽然gm与Tcw和果胶含量呈负相关，但Tcw和果胶之间存在正相关关系，表明果胶可能有助于确定细胞壁孔隙度。虽然我们的研究结果不允许我们提供结论性的声明，我们第一次建议，细胞壁成分-果胶发挥关键作用-可以强烈影响TCW和GM在南极苔藓，最终定义光合作用。本文受版权保护。All rights reserved.
Cell wall thickness (Tcw ) has been proposed as an important anatomical trait that could determine photosynthesis through land plants' phylogeny, bryophytes being the plant group presenting the thickest walls and the lowest photosynthetic rates. Also, it has recently been suggested that cell wall composition may have the potential to influence both thickness and mesophyll conductance (gm ), representing a novel trait that could ultimately affect photosynthesis. However, only a few studies in spermatophytes have demonstrated this issue. In order to explore the role of cell wall composition in determining both Tcw and gm in mosses, we tested six species grown under field conditions in Antarctica. We performed gas exchange and chlorophyll fluorescence measurements, an anatomical characterization, and a quantitative analysis of cell wall main composition (i.e., cellulose, hemicelluloses and pectins) in these six species. We found the photosynthetic rates to vary between the species, and they also presented differences in anatomical characteristics and in cell wall composition. Whilst gm correlated negatively with Tcw and pectins content, a positive relationship between Tcw and pectins emerged, suggesting that pectins could contribute to determine cell wall porosity. Although our results do not allow us to provide conclusive statements, we suggest for the first time that cell wall composition -with pectins playing a key role- could strongly influence Tcw and gm in Antarctic mosses, ultimately defining photosynthesis. This article is protected by copyright. All rights reserved.