Cargando…

Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions

Poa alpigena is a dominant grass species in alpine meadows, which is sensitive to environmental conditions. In this study, we analyzed the characteristics of the anatomical structure of the stems and leaves of Poa alpigena in overgrazed and enclosed conditions in order to determine the dwarfing morp...

Descripción completa

Detalles Bibliográficos
Autores principales: Shi, Hongxiao, Wu, Xinhong, Wang, Hai, Ha, Sibagen, Yang, Tingting, Liu, Wenhui
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8839268/
https://www.ncbi.nlm.nih.gov/pubmed/35161317
http://dx.doi.org/10.3390/plants11030336
_version_ 1784650328724996096
author Shi, Hongxiao
Wu, Xinhong
Wang, Hai
Ha, Sibagen
Yang, Tingting
Liu, Wenhui
author_facet Shi, Hongxiao
Wu, Xinhong
Wang, Hai
Ha, Sibagen
Yang, Tingting
Liu, Wenhui
author_sort Shi, Hongxiao
collection PubMed
description Poa alpigena is a dominant grass species in alpine meadows, which is sensitive to environmental conditions. In this study, we analyzed the characteristics of the anatomical structure of the stems and leaves of Poa alpigena in overgrazed and enclosed conditions in order to determine the dwarfing morphological mechanism associated with overgrazing. The results show that leaf thickness, leaf epidermal thickness, epidermal cell area, and phloem thickness increased with increased grazing intensity (p < 0.05). In contrast, xylem thickness, mesophyll cell area, and guide wall thickness decreased with an increase in grazing intensity (p < 0.05). Mesophyll cell density was relatively unaffected by grazing intensity. Additionally, the plasticity indices of leaf area, upper epidermal cutin layer thickness, and leaf xylem thickness were higher than 0.5. The plasticity indices of stem tube diameter, epidermal cell size, and epidermal cuticle thickness were greater than 0.4. The results of our study indicate that the structural stem and leaf changes in Poa alpigena are induced by the water and mechanical stresses that occur under grazing conditions. Thus, plateau plants adapt to grazing stress by increasing the thickness of their leaves, cuticles, and phloem. The mesophyll cell area, as well as the stem epidermal cell area of Poa alpigena decreased in response to minor variations in grazing intensity, yet overgrazing did not change its density. However, overgrazing induced a shortening of the leaves and stems, indicating that overgrazing has a dwarfing effect on Poa alpigena.
format Online
Article
Text
id pubmed-8839268
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-88392682022-02-13 Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions Shi, Hongxiao Wu, Xinhong Wang, Hai Ha, Sibagen Yang, Tingting Liu, Wenhui Plants (Basel) Article Poa alpigena is a dominant grass species in alpine meadows, which is sensitive to environmental conditions. In this study, we analyzed the characteristics of the anatomical structure of the stems and leaves of Poa alpigena in overgrazed and enclosed conditions in order to determine the dwarfing morphological mechanism associated with overgrazing. The results show that leaf thickness, leaf epidermal thickness, epidermal cell area, and phloem thickness increased with increased grazing intensity (p < 0.05). In contrast, xylem thickness, mesophyll cell area, and guide wall thickness decreased with an increase in grazing intensity (p < 0.05). Mesophyll cell density was relatively unaffected by grazing intensity. Additionally, the plasticity indices of leaf area, upper epidermal cutin layer thickness, and leaf xylem thickness were higher than 0.5. The plasticity indices of stem tube diameter, epidermal cell size, and epidermal cuticle thickness were greater than 0.4. The results of our study indicate that the structural stem and leaf changes in Poa alpigena are induced by the water and mechanical stresses that occur under grazing conditions. Thus, plateau plants adapt to grazing stress by increasing the thickness of their leaves, cuticles, and phloem. The mesophyll cell area, as well as the stem epidermal cell area of Poa alpigena decreased in response to minor variations in grazing intensity, yet overgrazing did not change its density. However, overgrazing induced a shortening of the leaves and stems, indicating that overgrazing has a dwarfing effect on Poa alpigena. MDPI 2022-01-27 /pmc/articles/PMC8839268/ /pubmed/35161317 http://dx.doi.org/10.3390/plants11030336 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Shi, Hongxiao
Wu, Xinhong
Wang, Hai
Ha, Sibagen
Yang, Tingting
Liu, Wenhui
Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions
title Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions
title_full Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions
title_fullStr Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions
title_full_unstemmed Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions
title_short Dwarfing and the Underlying Morphological Changes of Poa alpigena Plants in Response to Overgrazing Conditions
title_sort dwarfing and the underlying morphological changes of poa alpigena plants in response to overgrazing conditions
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8839268/
https://www.ncbi.nlm.nih.gov/pubmed/35161317
http://dx.doi.org/10.3390/plants11030336
work_keys_str_mv AT shihongxiao dwarfingandtheunderlyingmorphologicalchangesofpoaalpigenaplantsinresponsetoovergrazingconditions
AT wuxinhong dwarfingandtheunderlyingmorphologicalchangesofpoaalpigenaplantsinresponsetoovergrazingconditions
AT wanghai dwarfingandtheunderlyingmorphologicalchangesofpoaalpigenaplantsinresponsetoovergrazingconditions
AT hasibagen dwarfingandtheunderlyingmorphologicalchangesofpoaalpigenaplantsinresponsetoovergrazingconditions
AT yangtingting dwarfingandtheunderlyingmorphologicalchangesofpoaalpigenaplantsinresponsetoovergrazingconditions
AT liuwenhui dwarfingandtheunderlyingmorphologicalchangesofpoaalpigenaplantsinresponsetoovergrazingconditions