Higher Stomatal Density Improves Photosynthetic Induction and Biomass Production in Arabidopsis Under Fluctuating Light

• Published in: Frontiers in plant science Vol. 11; p. 589603
• Main Authors: Sakoda, Kazuma, Yamori, Wataru, Shimada, Tomoo, Sugano, Shigeo S, Hara-Nishimura, Ikuko, Tanaka, Yu
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 21-10-2020
• Subjects: fluctuating light; leaf photosynthesis; photosynthetic induction; Plant Science; stomata; stomatal density and conductance; water use efficiency; water use efficiency; stomata; leaf photosynthesis; photosynthetic induction; fluctuating light; stomatal density and conductance
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2020.589603

Stomatal density (
) is closely associated with photosynthetic and growth characteristics in plants. In the field, light intensity can fluctuate drastically within a day. The objective of the present study is to examine how higher
affects stomatal conductance (
) and CO
assimilation rate (
) dynamics, biomass production and water use under fluctuating light. Here, we compared the photosynthetic and growth characteristics under constant and fluctuating light among three lines of
(L.): the wild type (WT),
-overexpressing line (ST-OX), and
knockout line (
). ST-OX and
showed 268.1 and 46.5% higher
than WT (
< 0.05). Guard cell length of ST-OX was 10.0% lower than that of WT (
< 0.01). There were no significant variations in gas exchange parameters at steady state between WT and ST-OX or
, although these parameters tended to be higher in ST-OX and
than WT. On the other hand, ST-OX and
showed faster
induction than WT after step increase in light owing to the higher
under initial dark condition. In addition, ST-OX and
showed initially faster
induction and, at the later phase, slower
induction. Cumulative CO
assimilation in ST-OX and
was 57.6 and 78.8% higher than WT attributable to faster
induction with reduction of water use efficiency (
).
yielded 25.6% higher biomass than WT under fluctuating light (
< 0.01). In the present study, higher
resulted in faster photosynthetic induction owing to the higher initial
.
, with a moderate increase in
, achieved greater biomass production than WT under fluctuating light. These results suggest that higher
can be beneficial to improve biomass production in plants under fluctuating light conditions.