Photosynthetic energy conversion under extreme conditions - II: the significance of lipids under light limited growth in Antarctic sea ice diatoms

被引:88
作者
Mock, T
Kroon, BMA
机构
[1] Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany
[2] KroonAqa GmbH, D-27572 Bremerhaven, Germany
关键词
bacillariophyceae; carbohydrates; fluorescence induction; lipids; low temperature; pigments; proteins; sea ice;
D O I
10.1016/S0031-9422(02)00215-7
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Low photosynthetic active radiation is a strong determinant in the development and growth of sea ice algae. The algae appear to have universal mechanisms to overcome light limitation. One important process, which is induced under light limitation, is the desaturation of chloroplast membrane lipids. In order to discover whether this process is universally valid in sea ice diatoms, we investigated three species coexisting in chemostats illuminated with 15 and 2 mumol photons m(-2) s(-1) at 1 degreesC. Growth under 2 mumol photons m(-2) s(-1) caused a 50% increase in monogalactosyldiacylglycerols (MGDG) thylakoid membrane related 20:5 n-3 fatty acids. This fatty acid supports the fluidity of the thylakoid membrane and therefore the velocity of electron flow, which is indicated by increasing rate constants for the electron transport between Q(A) (first stable electron acceptor) and bound Q(B) (second stable electron acceptor) (11.16 +/- 1.34 to 23.24 +/- 1.35 relative units). Two mumol photons m(-2) s(-1) furthermore resulted in higher amounts of non-lipid bilayer forming MGDG in relation to other bilayer forming lipids, especially digalactosydiacylglycerol (DGDG). The ratio of MGDG:DGDG increased from 3.4 +/- 0.3 to 5.7 +/- 0.3. The existence of bilayer thylakoid membranes with high proportions of non. bilayer forming lipids is only possible when sufficient thylakoid pigment-protein complexes are present. If more thylakoid pigment-protein complexes are present in membranes, as found under extreme light limitation, less bilayer forming lipids such as DGDG are required to stabilize the bilayer structure. Differences in protein contents between both light intensities were not found. Consequently pigment contents which nearly doubled under 2 mumol photons m(-2) s(-1) must be responsible in balancing the potential stability loss resulting from an increase in MGDG:DGDG ratio. (C) 2002 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:53 / 60
页数:8
相关论文
共 23 条
[1]  
BLOCK MA, 1983, J BIOL CHEM, V258, P3281
[2]   EFFECT OF ENVIRONMENTAL-CONDITIONS ON FATTY-ACID COMPOSITION OF THE RED ALGA PORPHYRIDIUM-CRUENTUM - CORRELATION TO GROWTH-RATE [J].
COHEN, Z ;
VONSHAK, A ;
RICHMOND, A .
JOURNAL OF PHYCOLOGY, 1988, 24 (03) :328-332
[3]   A MODEL FOR THE RELATIONSHIP BETWEEN LIGHT-INTENSITY AND THE RATE OF PHOTOSYNTHESIS IN PHYTOPLANKTON [J].
EILERS, PHC ;
PEETERS, JCH .
ECOLOGICAL MODELLING, 1988, 42 (3-4) :199-215
[4]   LIGHT-SHADE ADAPTATION - 2 STRATEGIES IN MARINE-PHYTOPLANKTON [J].
FALKOWSKI, PG ;
OWENS, TG .
PLANT PHYSIOLOGY, 1980, 66 (04) :592-595
[5]   A dynamic regulatory model of phytoplanktonic acclimation to light, nutrients, and temperature [J].
Geider, RJ ;
MacIntyre, HL ;
Kana, TM .
LIMNOLOGY AND OCEANOGRAPHY, 1998, 43 (04) :679-694
[6]  
Geider RJ, 1996, LIMNOL OCEANOGR, V41, P1
[7]  
HARWOOD JL, 1989, ADV BOT RES, V16, P1
[8]   ROLE OF LIPIDS IN THE ORGANIZATION AND FUNCTION OF PHOTOSYSTEM-II STUDIED BY HOMOGENEOUS CATALYTIC-HYDROGENATION OF THYLAKOID MEMBRANES INSITU [J].
HORVATH, G ;
MELIS, A ;
HIDEG, E ;
DROPPA, M ;
VIGH, L .
BIOCHIMICA ET BIOPHYSICA ACTA, 1987, 891 (01) :68-74
[9]   Biodiversity of plankton by species oscillations and chaos [J].
Huisman, J ;
Weissing, FJ .
NATURE, 1999, 402 (6760) :407-410
[10]   LIPID COMPONENTS OF DIATOMS [J].
KATES, M ;
VOLCANI, BE .
BIOCHIMICA ET BIOPHYSICA ACTA, 1966, 116 (02) :264-&