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Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize

Increasing temperatures and extended drought episodes are among the major constraints affecting food production. Maize has a relatively high temperature optimum for photosynthesis compared to C(3) crops, however, the response of this important C(4) crop to the combination of heat and drought stress...

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Autores principales: Correia, Pedro M. P., da Silva, Anabela Bernardes, Vaz, Margarida, Carmo-Silva, Elizabete, Marques da Silva, Jorge
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8350398/
https://www.ncbi.nlm.nih.gov/pubmed/34381474
http://dx.doi.org/10.3389/fpls.2021.675546
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author Correia, Pedro M. P.
da Silva, Anabela Bernardes
Vaz, Margarida
Carmo-Silva, Elizabete
Marques da Silva, Jorge
author_facet Correia, Pedro M. P.
da Silva, Anabela Bernardes
Vaz, Margarida
Carmo-Silva, Elizabete
Marques da Silva, Jorge
author_sort Correia, Pedro M. P.
collection PubMed
description Increasing temperatures and extended drought episodes are among the major constraints affecting food production. Maize has a relatively high temperature optimum for photosynthesis compared to C(3) crops, however, the response of this important C(4) crop to the combination of heat and drought stress is poorly understood. Here, we hypothesized that resilience to high temperature combined with water deficit (WD) would require efficient regulation of the photosynthetic traits of maize, including the C(4)–CO(2) concentrating mechanism (CCM). Two genotypes of maize with contrasting levels of drought and heat tolerance, B73 and P0023, were acclimatized at high temperature (38°C versus 25°C) under well-watered (WW) or WD conditions. The photosynthetic performance was evaluated by gas exchange and chlorophyll a fluorescence, and in vitro activities of key enzymes for carboxylation (phosphoenolpyruvate carboxylase), decarboxylation (NADP-malic enzyme), and carbon fixation (Rubisco). Both genotypes successfully acclimatized to the high temperature, although with different mechanisms: while B73 maintained the photosynthetic rates by increasing stomatal conductance (gs), P0023 maintained gs and showed limited transpiration. When WD was experienced in combination with high temperatures, limited transpiration allowed water-savings and acted as a drought stress avoidance mechanism. The photosynthetic efficiency in P0023 was sustained by higher phosphorylated PEPC and electron transport rate (ETR) near vascular tissues, supplying chemical energy for an effective CCM. These results suggest that the key traits for drought and heat tolerance in maize are limited transpiration rate, allied with a synchronized regulation of the carbon assimilation metabolism. These findings can be exploited in future breeding efforts aimed at improving maize resilience to climate change.
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spelling pubmed-83503982021-08-10 Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize Correia, Pedro M. P. da Silva, Anabela Bernardes Vaz, Margarida Carmo-Silva, Elizabete Marques da Silva, Jorge Front Plant Sci Plant Science Increasing temperatures and extended drought episodes are among the major constraints affecting food production. Maize has a relatively high temperature optimum for photosynthesis compared to C(3) crops, however, the response of this important C(4) crop to the combination of heat and drought stress is poorly understood. Here, we hypothesized that resilience to high temperature combined with water deficit (WD) would require efficient regulation of the photosynthetic traits of maize, including the C(4)–CO(2) concentrating mechanism (CCM). Two genotypes of maize with contrasting levels of drought and heat tolerance, B73 and P0023, were acclimatized at high temperature (38°C versus 25°C) under well-watered (WW) or WD conditions. The photosynthetic performance was evaluated by gas exchange and chlorophyll a fluorescence, and in vitro activities of key enzymes for carboxylation (phosphoenolpyruvate carboxylase), decarboxylation (NADP-malic enzyme), and carbon fixation (Rubisco). Both genotypes successfully acclimatized to the high temperature, although with different mechanisms: while B73 maintained the photosynthetic rates by increasing stomatal conductance (gs), P0023 maintained gs and showed limited transpiration. When WD was experienced in combination with high temperatures, limited transpiration allowed water-savings and acted as a drought stress avoidance mechanism. The photosynthetic efficiency in P0023 was sustained by higher phosphorylated PEPC and electron transport rate (ETR) near vascular tissues, supplying chemical energy for an effective CCM. These results suggest that the key traits for drought and heat tolerance in maize are limited transpiration rate, allied with a synchronized regulation of the carbon assimilation metabolism. These findings can be exploited in future breeding efforts aimed at improving maize resilience to climate change. Frontiers Media S.A. 2021-07-26 /pmc/articles/PMC8350398/ /pubmed/34381474 http://dx.doi.org/10.3389/fpls.2021.675546 Text en Copyright © 2021 Correia, da Silva, Vaz, Carmo-Silva and Marques da Silva. https://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
Correia, Pedro M. P.
da Silva, Anabela Bernardes
Vaz, Margarida
Carmo-Silva, Elizabete
Marques da Silva, Jorge
Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize
title Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize
title_full Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize
title_fullStr Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize
title_full_unstemmed Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize
title_short Efficient Regulation of CO(2) Assimilation Enables Greater Resilience to High Temperature and Drought in Maize
title_sort efficient regulation of co(2) assimilation enables greater resilience to high temperature and drought in maize
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8350398/
https://www.ncbi.nlm.nih.gov/pubmed/34381474
http://dx.doi.org/10.3389/fpls.2021.675546
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