期刊
PHOTOSYNTHESIS RESEARCH
卷 85, 期 3, 页码 307-317出版社
SPRINGER
DOI: 10.1007/s11120-005-5668-9
关键词
acclimation; diatom; electron transport; Fragilariopsis cylindrus; low temperature; macroarray; polar; PSII
Cultures of the obligate psychrophilic diatom Fragilariopsis cylindrus (Grunow) were grown for 4 months under steady-state conditions at -1 degrees C and +7 degrees C (50 mu mol photons m(-2) s(-1)) prior to measurements in order to investigate long-term acclimation of photosynthesis to both temperatures. No differences in maximum intrinsic quantum yield of PS II (F-V/F-M) and relative electron transport rates could be detected at either temperature after 4 months of acclimation. Measurements of photosynthesis (relative electron transport rates) vs. irradiance (P vs. E curves) revealed similar values for relative light utilization efficiency (alpha = 0.57 at -1 degrees C, alpha = 0.60 at +7 degrees C) but higher values for irradiance levels at which photosynthesis saturates (E-K) at -1 degrees C and, therefore, higher maximum photosynthesis (P-MAX = 54 (relative units) at -1 degrees C, P-MAX = 49 at +7 degrees C). Nonphotochemical quenching (NPQ) measurements at 385 mu mol photons m(-2) s(-1) indicated higher (37%) NPQ for diatoms grown at -1 degrees C compared to +7 degrees C, which was possibly related to a 2-fold increase in the concentration of the pigment diatoxanthin and a 9-fold up-regulation of a gene encoding a fucoxanthin chlorophyll a,c-binding protein. Expression of the D1 protein encoding gene psbA was ca. 1.5-fold up-regulated at -1 degrees C, whereas expression levels of other genes from Photosystem II (psbC, psbU, psbO), as well as rbcL, the gene encoding the Rubisco large subunit were similar at both temperatures. However, a 2-fold up-regulation of a plastid glyceraldehyde-P dehydrogenase at -1 degrees C indicated enhanced Calvin cycle activity. This study revealed for the first time that a polar diatom could efficiently acclimate photosynthesis over a wide range of polar temperatures given enough time. Acclimation of photosynthesis at -1 degrees C was probably regulated similarly to high light acclimation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据