Evidence of Global Chlorophyll d
Y. Kashiyama,1*
H. Miyashita,2
S. Ohkubo,2
N. O. Ogawa,1
Y. Chikaraishi,1
Y. Takano,1
H. Suga,1
T. Toyofuku,1
H. Nomaki,1
H. Kitazato,1
T. Nagata,3
N. Ohkouchi1
Although analyses of chlorophyll d (Chl d)-dominated oxygenic
photosystems have been conducted since their discovery 12 years
ago, Chl d distribution in the environment and quantitative
importance for aquatic photosynthesis remain to be investigated.
We analyzed the pigment compositions of surface sediments and
detected Chl d and its derivatives from diverse aquatic environments.
Our data show that the viable habitat for Chl d-producing phototrophs
extends across salinities of 0 to 50 practical salinity units
and temperatures of 1° to 40°C, suggesting that Chl d production
can be ubiquitously observed in aquatic environments that receive
near-infrared light. The relative abundances of Chl d derivatives
over that of Chl a derivatives in the studied samples are up
to 4%, further suggesting that Chl d-based photosynthesis plays
a quantitatively important role in the aquatic photosynthesis.
2 Department of Interdisciplinary Environment, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan.
3 Center for Ecological Research, Kyoto University, Otsu 520-2113, Japan.
Present address: Ocean Research Institute, University of Tokyo, Tokyo 164-8639, Japan.
* To whom correspondence should be addressed. E-mail: chiro{at}jamstec.go.jp
