AUTHOR=Wei Yaxi , Li Zhen , Zhang Jiaolong , Hu Dan 

TITLE=Effects of artificial light at night and drought on the photosynthesis and physiological traits of two urban plants

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1263795

DOI=10.3389/fpls.2023.1263795

ISSN=1664-462X

ABSTRACT=<p>Urban plants are currently confronted with the stresses posed by artificial light at night (ALAN) and drought. A field block experiment was designed to explore the potential effects of ALAN and drought on the photosynthesis and physiological characters of two common urban plants, <italic>Euonymus japonicus</italic> (<italic>E. japonicus</italic>) and <italic>Rosa hybrida</italic> (<italic>R. hybrida</italic>). Each plant species was subjected to four distinct treatments: neither ALAN nor drought, ALAN, drought, and both ALAN and drought. The result showed the following: (1) ALAN significantly reduced the effective quantum yield (Φ<sub>PSII</sub>), apparent electron transfer rate (ETR), photochemical quenching parameter (<sub>q</sub>p), net photosynthetic (Pn), stomatal conductance (Gs), stomatal limit value (Ls), and the pigment concentrations and remarkably increased the content of malondialdehyde (MDA), total antioxidant capacity (TAC), and starch in both <italic>E. japonicus</italic> and <italic>R. hybrida</italic>. Furthermore, ALAN increased the soluble saccharides of <italic>E. japonicus</italic>, and this effect of ALAN also occurred on <italic>R. hybrida</italic> under drought. (2) Drought significantly decreased the Φ<sub>PSII</sub>, ETR, <sub>q</sub>p, Pn, Gs, Ls, and the pigment concentrations and remarkably increased the content of MDA and TAC for both <italic>E. japonicus</italic> and <italic>R. hybrida</italic>. Moreover, drought did not significantly change the starch content of both species, and it significantly increased the content of soluble saccharides for <italic>E. japonicus.</italic> (3) The interaction between ALAN and drought occurred on the Φ<sub>PSII</sub>, ETR, Pn, MDA, and TAC of <italic>E. japonicus</italic>, but had no effect on <italic>R. hybrida</italic>. For urban areas affected by ALAN and drought, it is advisable to select plant species with strong stress resistance for gardening purposes, and plants directly exposed to ALAN should receive sufficient water during hot and dry weather conditions to maintain their normal growth.</p>