Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in Grapevine

Semi-arid viticultural regions globally are experiencing severe and frequent growing-season heat waves that negatively impact grapevine (<i>Vitis vinifera</i> L.) physiological performance and productivity. At the leaf level, heat stress can photodamage both Photosystem I (PSI) and Photo...

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Main Authors: Qian Qiu, Yanli Sun, Dinghan Guo, Lei Wang, Vinay Pagay, Shiping Wang
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Agronomy
Subjects:
Online Access:https://www.mdpi.com/2073-4395/15/4/948
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author Qian Qiu
Yanli Sun
Dinghan Guo
Lei Wang
Vinay Pagay
Shiping Wang
author_facet Qian Qiu
Yanli Sun
Dinghan Guo
Lei Wang
Vinay Pagay
Shiping Wang
author_sort Qian Qiu
collection DOAJ
description Semi-arid viticultural regions globally are experiencing severe and frequent growing-season heat waves that negatively impact grapevine (<i>Vitis vinifera</i> L.) physiological performance and productivity. At the leaf level, heat stress can photodamage both Photosystem I (PSI) and Photosystem II (PSII). In order to study the self-protection mechanism of grapevine leaves, in this study, 3-year-old potted ‘Merlot’ and ‘Muscat Hamburg’ grapevines were exposed to a 5-day simulated heatwave (45/25 °C day/night) and compared to vines maintained at 25/18 °C. After heat exposure, ‘Merlot’ demonstrated superior thermotolerance and superior physiological performance as measured by gas exchange, oxidative parameters, chlorophyll loss, and photoinhibition of PSI and PSII. Additionally, non-photochemical quenching (NPQ) dissipated the excess light energy in the form of heat. Y(NPQ) progressively rose from 0 to 0.6, signaling the start of the grapevine leaves’ self-defense against temperature stress. Furthermore, the stimulation of cyclic electron flow (CEF) under high temperatures contributed to the energy balance of PSI. The CEF of ‘Muscat Hamburg’ under high light intensities increased dramatically from 1 to 4. NAD(P)H dehydrogenase-dependent CEF around PSI increased markedly, suggesting its role in self-protection. These results demonstrate that both NPQ and CEF play key photoprotective roles by generating a proton gradient under heat stress.
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issn 2073-4395
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spelling doaj-art-c7bf2ff042ec4003969441759dae5f342025-08-20T02:17:19ZengMDPI AGAgronomy2073-43952025-04-0115494810.3390/agronomy15040948Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in GrapevineQian Qiu0Yanli Sun1Dinghan Guo2Lei Wang3Vinay Pagay4Shiping Wang5Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, ChinaDepartment of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, ChinaDepartment of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, ChinaDepartment of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, ChinaSchool of Agriculture, Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, AustraliaDepartment of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, ChinaSemi-arid viticultural regions globally are experiencing severe and frequent growing-season heat waves that negatively impact grapevine (<i>Vitis vinifera</i> L.) physiological performance and productivity. At the leaf level, heat stress can photodamage both Photosystem I (PSI) and Photosystem II (PSII). In order to study the self-protection mechanism of grapevine leaves, in this study, 3-year-old potted ‘Merlot’ and ‘Muscat Hamburg’ grapevines were exposed to a 5-day simulated heatwave (45/25 °C day/night) and compared to vines maintained at 25/18 °C. After heat exposure, ‘Merlot’ demonstrated superior thermotolerance and superior physiological performance as measured by gas exchange, oxidative parameters, chlorophyll loss, and photoinhibition of PSI and PSII. Additionally, non-photochemical quenching (NPQ) dissipated the excess light energy in the form of heat. Y(NPQ) progressively rose from 0 to 0.6, signaling the start of the grapevine leaves’ self-defense against temperature stress. Furthermore, the stimulation of cyclic electron flow (CEF) under high temperatures contributed to the energy balance of PSI. The CEF of ‘Muscat Hamburg’ under high light intensities increased dramatically from 1 to 4. NAD(P)H dehydrogenase-dependent CEF around PSI increased markedly, suggesting its role in self-protection. These results demonstrate that both NPQ and CEF play key photoprotective roles by generating a proton gradient under heat stress.https://www.mdpi.com/2073-4395/15/4/948grapephotosynthesisextreme heat stressphotosystem Icyclic electron flow
spellingShingle Qian Qiu
Yanli Sun
Dinghan Guo
Lei Wang
Vinay Pagay
Shiping Wang
Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in Grapevine
Agronomy
grape
photosynthesis
extreme heat stress
photosystem I
cyclic electron flow
title Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in Grapevine
title_full Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in Grapevine
title_fullStr Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in Grapevine
title_full_unstemmed Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in Grapevine
title_short Heat Stress Downregulates Photosystem I Redox State on Leaf Photosynthesis in Grapevine
title_sort heat stress downregulates photosystem i redox state on leaf photosynthesis in grapevine
topic grape
photosynthesis
extreme heat stress
photosystem I
cyclic electron flow
url https://www.mdpi.com/2073-4395/15/4/948
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AT yanlisun heatstressdownregulatesphotosystemiredoxstateonleafphotosynthesisingrapevine
AT dinghanguo heatstressdownregulatesphotosystemiredoxstateonleafphotosynthesisingrapevine
AT leiwang heatstressdownregulatesphotosystemiredoxstateonleafphotosynthesisingrapevine
AT vinaypagay heatstressdownregulatesphotosystemiredoxstateonleafphotosynthesisingrapevine
AT shipingwang heatstressdownregulatesphotosystemiredoxstateonleafphotosynthesisingrapevine