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Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue
Summer dormancy is an evolutionary response that some perennial cool-season grasses adopted as an avoidance strategy to escape summer drought and heat. It is correlated with superior survival after severe summer droughts in many perennial grass species originating from Mediterranean environments. Un...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5698279/ https://www.ncbi.nlm.nih.gov/pubmed/29204152 http://dx.doi.org/10.3389/fpls.2017.01971 |
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author | Missaoui, Ali M. Malinowski, Dariusz P. Pinchak, William E. Kigel, Jaime |
author_facet | Missaoui, Ali M. Malinowski, Dariusz P. Pinchak, William E. Kigel, Jaime |
author_sort | Missaoui, Ali M. |
collection | PubMed |
description | Summer dormancy is an evolutionary response that some perennial cool-season grasses adopted as an avoidance strategy to escape summer drought and heat. It is correlated with superior survival after severe summer droughts in many perennial grass species originating from Mediterranean environments. Understanding the genetic mechanism and environmental determinants of summer dormancy is important for interpreting the evolutionary history of seasonal dormancy and for the development of genomic tools to improve the efficiency of genetic selection for this important trait. The objectives of this research are to assess morphological and biochemical attributes that seem to be specific for the characterization of summer dormancy in tall fescue, and to validate the hypothesis that genes underlying stem determinacy might be involved in the mechanism of summer dormancy. Our results suggest that vernalization is an important requirement in the onset of summer dormancy in tall fescue. Non-vernalized tall fescue plants do not exhibit summer dormancy as vernalized plants do and behave more like summer-active types. This is manifested by continuation of shoot growth and high root activity in water uptake during summer months. Therefore, summer dormancy in tall fescue should be tested only in plants that underwent vernalization and are not subjected to water deficit during summer months. Total phenolic concentration in tiller bases (antioxidants) does not seem to be related to vernalization. It is most likely an environmental response to protect meristems from oxidative stress. Sequence analysis of the TFL1 homolog CEN gene from tall fescue genotypes belonging to summer-dormant and summer-active tall fescue types showed a unique deletion of three nucleotides specific to the dormant genotypes. Higher tiller bud numbers in dormant plants that were not allowed to flower and complete the reproductive cycle, confirmed that stem determinacy is a major component in the mechanism of summer dormancy. The number of variables identified in these studies as potential players in summer dormancy in tall fescue including vernalization, TFL1/CEN, water status, and protection from oxidative stress are a further confirmation that summer dormancy is a quantitative trait controlled by several genes with varying effects and prone to genotype by environment interactions. |
format | Online Article Text |
id | pubmed-5698279 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-56982792017-12-04 Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue Missaoui, Ali M. Malinowski, Dariusz P. Pinchak, William E. Kigel, Jaime Front Plant Sci Plant Science Summer dormancy is an evolutionary response that some perennial cool-season grasses adopted as an avoidance strategy to escape summer drought and heat. It is correlated with superior survival after severe summer droughts in many perennial grass species originating from Mediterranean environments. Understanding the genetic mechanism and environmental determinants of summer dormancy is important for interpreting the evolutionary history of seasonal dormancy and for the development of genomic tools to improve the efficiency of genetic selection for this important trait. The objectives of this research are to assess morphological and biochemical attributes that seem to be specific for the characterization of summer dormancy in tall fescue, and to validate the hypothesis that genes underlying stem determinacy might be involved in the mechanism of summer dormancy. Our results suggest that vernalization is an important requirement in the onset of summer dormancy in tall fescue. Non-vernalized tall fescue plants do not exhibit summer dormancy as vernalized plants do and behave more like summer-active types. This is manifested by continuation of shoot growth and high root activity in water uptake during summer months. Therefore, summer dormancy in tall fescue should be tested only in plants that underwent vernalization and are not subjected to water deficit during summer months. Total phenolic concentration in tiller bases (antioxidants) does not seem to be related to vernalization. It is most likely an environmental response to protect meristems from oxidative stress. Sequence analysis of the TFL1 homolog CEN gene from tall fescue genotypes belonging to summer-dormant and summer-active tall fescue types showed a unique deletion of three nucleotides specific to the dormant genotypes. Higher tiller bud numbers in dormant plants that were not allowed to flower and complete the reproductive cycle, confirmed that stem determinacy is a major component in the mechanism of summer dormancy. The number of variables identified in these studies as potential players in summer dormancy in tall fescue including vernalization, TFL1/CEN, water status, and protection from oxidative stress are a further confirmation that summer dormancy is a quantitative trait controlled by several genes with varying effects and prone to genotype by environment interactions. Frontiers Media S.A. 2017-11-17 /pmc/articles/PMC5698279/ /pubmed/29204152 http://dx.doi.org/10.3389/fpls.2017.01971 Text en Copyright © 2017 Missaoui, Malinowski, Pinchak and Kigel. 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) or licensor 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 Missaoui, Ali M. Malinowski, Dariusz P. Pinchak, William E. Kigel, Jaime Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue |
title | Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue |
title_full | Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue |
title_fullStr | Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue |
title_full_unstemmed | Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue |
title_short | Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue |
title_sort | insights into the drought and heat avoidance mechanism in summer-dormant mediterranean tall fescue |
topic | Plant Science |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5698279/ https://www.ncbi.nlm.nih.gov/pubmed/29204152 http://dx.doi.org/10.3389/fpls.2017.01971 |
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