Leaf temperature and CO2 effects on photosynthetic CO2 assimilation and chlorophyll a fluorescence light responses during mid-ripening of Vitis vinifera cv. Shiraz grapevines grown in outdoor conditions

Dennis Greer

    Research output: Contribution to journalArticlepeer-review

    Abstract

    Responses of CO2 assimilation and chlorophyll a fluorescence to light intensity for Shiraz leaves on vines grown outdoors were examined in relation to leaf temperature. The study aimed to assess whether perturbing the carbon source, by manipulating short-term CO2 concentrations, would affect photosynthetic responses to temperature. Strong interactions occurred between leaf temperature and CO2 on photosynthetic and electron transport light responses. Most responses to temperature occurred at low to moderate CO2 and little response to temperature occurred at high CO2. While assimilation responses accorded with increasing substrate CO2, electron transport was inhibited by elevated CO2. By contrast, chlorophyll a fluorescence was not affected by a temperature × CO2 interaction and CO2 had no effect on PSII quantum efficiency or photochemical quenching; whereas there was a moderate effect of temperature. Quantum efficiency of PSII was most severely reduced at low temperatures. Most photochemical quenching also occurred at low temperatures and the least at 40°C, in keeping with the warm to hot growth climate and the apparent assimilation bias towards the higher temperatures of the growing season. No changes in temperature dependency of assimilation were detected at the different CO2 concentrations, confirming sinks have a greater effect on assimilation than does the source.
    Original languageEnglish
    Pages (from-to)659-671
    Number of pages13
    JournalFunctional Plant Biology
    Volume49
    Issue number7
    DOIs
    Publication statusPublished - 28 Mar 2022

    Fingerprint

    Dive into the research topics of 'Leaf temperature and CO2 effects on photosynthetic CO2 assimilation and chlorophyll a fluorescence light responses during mid-ripening of Vitis vinifera cv. Shiraz grapevines grown in outdoor conditions'. Together they form a unique fingerprint.

    Cite this