Recent levels of daily photosynthetic photon flfl ux density have a larger inflfl uence on light acclimation responses of cucumber leaves than earlier levels

• Published in: Horticulture, environment and biotechnology pp. 55 - 64
• Main Authors: Liyao Yu, Kazuhiro Fujiwara, Ryo Matsuda
• Format: Journal Article
• Language: English
• Published: 한국원예학회 01.02.2022
• Subjects: 농학
• ISSN: 2211-3452; 2211-3460
• DOI: 10.1007/s13580-021-00375-6

Leaves respond to the photosynthetic photon fl ux density (PPFD) and accordingly adjust their morphological and physiologicalproperties, including leaf mass per area (LMA) and the chlorophyll (chl) a/b ratio. These responses are called light acclimationresponses. Although the properties that are responsive to high or low constant PPFD levels have been well described,the extent of the responses to changing PPFD, as observed in open fi elds and greenhouses, remains insuffi ciently quantifi ed. In this study, we quantitatively investigated the eff ects of changes among three PPFD levels (100, 400, and 700 μmol m −2 s −1 )over six days (constant within each day) on leaf light acclimation responses in cucumber ( Cucumis sativus ) seedlings. Weintroduced a time-weighted average PPFD ( L w ), in which the eff ect of the PPFD in the earlier growth period was given lessweight, and demonstrated a signifi cant linear regression of parameters of the leaf light acclimation responses including theLMA, chl a / b ratio, maximum rate of carboxylation capacity of ribulose-1,5-bisphosphate carboxylase/oxygenase ( V c max ) andmaximum rate of electron transport ( J max ) on L w . The result showed that the linear regression model with L w well explainedthe light acclimation responses of leaves to the day-to-day changes in daily PPFD and it estimated these response parametersmore accurately than a model with an average PPFD. KCI Citation Count: 0