Limits...
Utilizing the effective xanthophyll cycle for blooming of Ochromonas smithii and O. itoi (Chrysophyceae) on the snow surface.

Tanabe Y, Shitara T, Kashino Y, Hara Y, Kudoh S - PLoS ONE (2011)

Bottom Line: It is considered to be effective utilizing the xanthophyll cycle and holding sunscreen pigments as protective system for snow algae blooming in the vulnerable environment such as low temperature and nutrients, and strong light, however the study on the photoprotection of chrysophytes snow algae has not been shown.To dissolve how the chrysophytes snow algae can grow and bloom under such an extreme environment, we studied with the object of light which is one point of significance to this problem.This experimental study using unialgal cultures revealed that both O. smithii and O. itoi utilize only the efficient violaxanthin cycle for photoprotection as a dissipation system of surplus energy under prolonged high-light stress, although they possess chlorophyll c with diadinoxanthin.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Polar Research, Tachikawa, Japan. ukko@nipr.ac.jp

ABSTRACT
Snow algae inhabit unique environments such as alpine and high latitudes, and can grow and bloom with visualizing on snow or glacier during spring-summer. The chrysophytes Ochromonas smithii and Ochromonas itoi are dominant in yellow-colored snow patches in mountainous heavy snow areas from late May to early June. It is considered to be effective utilizing the xanthophyll cycle and holding sunscreen pigments as protective system for snow algae blooming in the vulnerable environment such as low temperature and nutrients, and strong light, however the study on the photoprotection of chrysophytes snow algae has not been shown. To dissolve how the chrysophytes snow algae can grow and bloom under such an extreme environment, we studied with the object of light which is one point of significance to this problem. We collected the yellow snows and measured photosynthetically active radiation at Mt. Gassan in May 2008 when the bloom occurred, then tried to establish unialgal cultures of O. smithii and O. itoi, and examined their photosynthetic properties by a PAM chlorophyll fluorometer and analyzed the pigment compositions before and after illumination with high-light intensities to investigate the working xanthophyll cycle. This experimental study using unialgal cultures revealed that both O. smithii and O. itoi utilize only the efficient violaxanthin cycle for photoprotection as a dissipation system of surplus energy under prolonged high-light stress, although they possess chlorophyll c with diadinoxanthin.

Show MeSH
Molecular structures of the xanthophyll cycle pigments mentioned in the text.Arrows between pigments denote enzymatic conversions caused by xanthophyll cycling.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3044130&req=5

pone-0014690-g001: Molecular structures of the xanthophyll cycle pigments mentioned in the text.Arrows between pigments denote enzymatic conversions caused by xanthophyll cycling.

Mentions: It has been generally recognized that photosynthetic organisms using the two major xanthophyll cycles to regulate dissipation of surplus light energy [9], [10] on a short time scale [11], [12] utilize either the violaxanthin (Vx) cycle, a reversible conversion of Vx, antheraxanthin (Ax), and zeaxanthin (Zx) in higher plants and green algae [13], [14] or the diadinoxanthin (Ddx) cycle, a conversion of Ddx and diatoxanthin (Dtx), in some chlorophyll (Chl.) a/c-containing algae such as diatoms, dinophytes, and haptophytes [15–17; Fig. 1]. Although the Vx cycle comprises two deepoxidation steps, the Ddx cycle involves a single step because only one of the ionone rings of Ddx carries an epoxide group (Fig. 1).


Utilizing the effective xanthophyll cycle for blooming of Ochromonas smithii and O. itoi (Chrysophyceae) on the snow surface.

Tanabe Y, Shitara T, Kashino Y, Hara Y, Kudoh S - PLoS ONE (2011)

Molecular structures of the xanthophyll cycle pigments mentioned in the text.Arrows between pigments denote enzymatic conversions caused by xanthophyll cycling.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3044130&req=5

pone-0014690-g001: Molecular structures of the xanthophyll cycle pigments mentioned in the text.Arrows between pigments denote enzymatic conversions caused by xanthophyll cycling.
Mentions: It has been generally recognized that photosynthetic organisms using the two major xanthophyll cycles to regulate dissipation of surplus light energy [9], [10] on a short time scale [11], [12] utilize either the violaxanthin (Vx) cycle, a reversible conversion of Vx, antheraxanthin (Ax), and zeaxanthin (Zx) in higher plants and green algae [13], [14] or the diadinoxanthin (Ddx) cycle, a conversion of Ddx and diatoxanthin (Dtx), in some chlorophyll (Chl.) a/c-containing algae such as diatoms, dinophytes, and haptophytes [15–17; Fig. 1]. Although the Vx cycle comprises two deepoxidation steps, the Ddx cycle involves a single step because only one of the ionone rings of Ddx carries an epoxide group (Fig. 1).

Bottom Line: It is considered to be effective utilizing the xanthophyll cycle and holding sunscreen pigments as protective system for snow algae blooming in the vulnerable environment such as low temperature and nutrients, and strong light, however the study on the photoprotection of chrysophytes snow algae has not been shown.To dissolve how the chrysophytes snow algae can grow and bloom under such an extreme environment, we studied with the object of light which is one point of significance to this problem.This experimental study using unialgal cultures revealed that both O. smithii and O. itoi utilize only the efficient violaxanthin cycle for photoprotection as a dissipation system of surplus energy under prolonged high-light stress, although they possess chlorophyll c with diadinoxanthin.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Polar Research, Tachikawa, Japan. ukko@nipr.ac.jp

ABSTRACT
Snow algae inhabit unique environments such as alpine and high latitudes, and can grow and bloom with visualizing on snow or glacier during spring-summer. The chrysophytes Ochromonas smithii and Ochromonas itoi are dominant in yellow-colored snow patches in mountainous heavy snow areas from late May to early June. It is considered to be effective utilizing the xanthophyll cycle and holding sunscreen pigments as protective system for snow algae blooming in the vulnerable environment such as low temperature and nutrients, and strong light, however the study on the photoprotection of chrysophytes snow algae has not been shown. To dissolve how the chrysophytes snow algae can grow and bloom under such an extreme environment, we studied with the object of light which is one point of significance to this problem. We collected the yellow snows and measured photosynthetically active radiation at Mt. Gassan in May 2008 when the bloom occurred, then tried to establish unialgal cultures of O. smithii and O. itoi, and examined their photosynthetic properties by a PAM chlorophyll fluorometer and analyzed the pigment compositions before and after illumination with high-light intensities to investigate the working xanthophyll cycle. This experimental study using unialgal cultures revealed that both O. smithii and O. itoi utilize only the efficient violaxanthin cycle for photoprotection as a dissipation system of surplus energy under prolonged high-light stress, although they possess chlorophyll c with diadinoxanthin.

Show MeSH