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With Over 60 Independent Losses, Stomata Are Expendable in Mosses

Because stomata in bryophytes are uniquely located on sporangia, the physiological and evolutionary constraints placed on bryophyte stomata are fundamentally different from those on leaves of tracheophytes. Although losses of stomata have been documented in mosses, the extent to which this evolution...

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Autores principales: Renzaglia, Karen S., Browning, William B., Merced, Amelia
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7270291/
https://www.ncbi.nlm.nih.gov/pubmed/32547571
http://dx.doi.org/10.3389/fpls.2020.00567
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author Renzaglia, Karen S.
Browning, William B.
Merced, Amelia
author_facet Renzaglia, Karen S.
Browning, William B.
Merced, Amelia
author_sort Renzaglia, Karen S.
collection PubMed
description Because stomata in bryophytes are uniquely located on sporangia, the physiological and evolutionary constraints placed on bryophyte stomata are fundamentally different from those on leaves of tracheophytes. Although losses of stomata have been documented in mosses, the extent to which this evolutionary process occurred remains relatively unexplored. We initiated this study by plotting the known occurrences of stomata loss and numbers per capsule on the most recent moss phylogeny. From this, we identified 40 families and 74 genera that lack stomata, of which at least 63 are independent losses. No trends in stomata losses or numbers are evident in any direction across moss diversity. Extant taxa in early divergent moss lineages either lack stomata or produce pseudostomata that do not form pores. The earliest land plant macrofossils from 400 ma exhibit similar sporangial morphologies and stomatal distribution to extant mosses, suggesting that the earliest mosses may have possessed and lost stomata as is common in the group. To understand why stomata are expendable in mosses, we conducted comparative anatomical studies on a range of mosses with and without stomata. We compared the anatomy of stomate and astomate taxa and the development of intercellular spaces, including substomatal cavities, across mosses. Two types of intercellular spaces that develop differently are seen in peristomate mosses, those associated with stomata and those that surround the spore sac. Capsule architecture in astomate mosses ranges from solid in the taxa in early divergent lineages to containing an internal space that is directly connected to the conducing tissue and is involved in capsule expansion and the nourishment, hydration and development of spores. This anatomy reveals there are different architectural arrangements of tissues within moss capsules that are equally effective in accomplishing the essential processes of sporogenesis and spore dispersal. Stomata are not foundational to these processes.
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spelling pubmed-72702912020-06-15 With Over 60 Independent Losses, Stomata Are Expendable in Mosses Renzaglia, Karen S. Browning, William B. Merced, Amelia Front Plant Sci Plant Science Because stomata in bryophytes are uniquely located on sporangia, the physiological and evolutionary constraints placed on bryophyte stomata are fundamentally different from those on leaves of tracheophytes. Although losses of stomata have been documented in mosses, the extent to which this evolutionary process occurred remains relatively unexplored. We initiated this study by plotting the known occurrences of stomata loss and numbers per capsule on the most recent moss phylogeny. From this, we identified 40 families and 74 genera that lack stomata, of which at least 63 are independent losses. No trends in stomata losses or numbers are evident in any direction across moss diversity. Extant taxa in early divergent moss lineages either lack stomata or produce pseudostomata that do not form pores. The earliest land plant macrofossils from 400 ma exhibit similar sporangial morphologies and stomatal distribution to extant mosses, suggesting that the earliest mosses may have possessed and lost stomata as is common in the group. To understand why stomata are expendable in mosses, we conducted comparative anatomical studies on a range of mosses with and without stomata. We compared the anatomy of stomate and astomate taxa and the development of intercellular spaces, including substomatal cavities, across mosses. Two types of intercellular spaces that develop differently are seen in peristomate mosses, those associated with stomata and those that surround the spore sac. Capsule architecture in astomate mosses ranges from solid in the taxa in early divergent lineages to containing an internal space that is directly connected to the conducing tissue and is involved in capsule expansion and the nourishment, hydration and development of spores. This anatomy reveals there are different architectural arrangements of tissues within moss capsules that are equally effective in accomplishing the essential processes of sporogenesis and spore dispersal. Stomata are not foundational to these processes. Frontiers Media S.A. 2020-05-28 /pmc/articles/PMC7270291/ /pubmed/32547571 http://dx.doi.org/10.3389/fpls.2020.00567 Text en Copyright © 2020 Renzaglia, Browning and Merced. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Plant Science
Renzaglia, Karen S.
Browning, William B.
Merced, Amelia
With Over 60 Independent Losses, Stomata Are Expendable in Mosses
title With Over 60 Independent Losses, Stomata Are Expendable in Mosses
title_full With Over 60 Independent Losses, Stomata Are Expendable in Mosses
title_fullStr With Over 60 Independent Losses, Stomata Are Expendable in Mosses
title_full_unstemmed With Over 60 Independent Losses, Stomata Are Expendable in Mosses
title_short With Over 60 Independent Losses, Stomata Are Expendable in Mosses
title_sort with over 60 independent losses, stomata are expendable in mosses
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7270291/
https://www.ncbi.nlm.nih.gov/pubmed/32547571
http://dx.doi.org/10.3389/fpls.2020.00567
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