Figure 1.
Molecular structures of the xanthophyll cycle pigments mentioned in the text.
Arrows between pigments denote enzymatic conversions caused by xanthophyll cycling.
Figure 2.
Microscopy photographs of A, Ochromonas itoi; B, Ochromonas smithii; C, landscape of yellow snow caused by Ochromonas itoi and Ochromonas smithii on/in the deposited snow surface in Mt. Gassan.
Figure 3.
Change in photosynthetic responses of Ochromonas itoi determined by a PAM fluorometer before illumination and after 6-h high-light (HL) illumination.
A, Relationship between photosynthetically active radiation (PAR) and photosystem II (PSII) yield; B, relationship between PAR and relative electron transport rate (rETR); C, relationship between PAR and non photochemical quenching (NPQ).
Table 1.
Pigment composition of Ochromonas itoi and Ochromonas smithii before high light (HL) and after 6-h HL incubation.
Figure 4.
Changes in xanthophyll cycle pigments in Ochromonas itoi and Ochromonas smithii after 6-h high-light (HL) incubation.
Figure 5.
Time course of xanthophyll cycle pigment changes in a cell suspension of Ochromonas itoi in low-light (LL) during 1-h illumination after 6-h high-light (HL) illumination.
Pigments are normalized to chlorophyll a (Chl.a). Values are means of three independent records, and error bars are standard deviations. A, Epoxidation of zeaxanthin (Zx) from antheraxanthin (Ax) to Vx; B, epoxidation of diatoxanthin (Dtx) to diadinoxanthin (Ddx).
Figure 6.
Time course of xanthophyll cycle pigment changes in Ochromonas itoi in high-light (HL) after 6-h HL illumination, followed by 1-h low-light (LL) illumination.
Pigments are normalized to chlorophyll a (Chl.a). Values are means of three independent records, and error bars are standard deviations. A, Deepoxidation of violaxanthin (Vx) from antheraxanthin (Ax) to zeaxanthin (Zx); B, deepoxidation of diadinoxanthin (Ddx) to diatoxanthin (Dtx).