کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1943588 1052674 2007 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Psychrophily is associated with differential energy partitioning, photosystem stoichiometry and polypeptide phosphorylation in Chlamydomonas raudensis
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
Psychrophily is associated with differential energy partitioning, photosystem stoichiometry and polypeptide phosphorylation in Chlamydomonas raudensis
چکیده انگلیسی

Chlamydomonas raudensis UWO 241 and SAG 49.72 represent the psychrophilic and mesophilic strains of this green algal species. This novel discovery was exploited to assess the role of psychrophily in photoacclimation to growth temperature and growth irradiance. At their optimal growth temperatures of 8 °C and 28 °C respectively, UWO 241 and SAG 49.72 maintained comparable photostasis, that is energy balance, as measured by PSII excitation pressure. Although UWO 241 exhibited higher excitation pressure, measured as 1-qL, at all growth light intensities, the relative changes in 1-qL were similar to that of SAG 49.72 in response to growth light. In response to suboptimal temperatures and increased growth irradiance, SAG 49.72 favoured energy partitioning of excess excitation energy through inducible, down regulatory processes (ΦNPQ) associated with the xanthophyll cycle and antenna quenching, while UWO 241 favoured xanthophyll cycle-independent energy partitioning through constitutive processes involved in energy dissipation (ΦNO). In contrast to SAG 49.72, an elevation in growth temperature induced an increase in PSI/PSII stoichiometry in UWO 241. Furthermore, SAG 49.72 showed typical threonine-phosphorylation of LHCII, whereas UWO 241 exhibited phosphorylation of polypeptides of comparable molecular mass to PSI reaction centres but the absence of LHCII phosphorylation. Thus, although both strains maintain an energy balance irrespective of their differences in optimal growth temperatures, the mechanisms used to maintain photostasis were distinct. We conclude that psychrophily in C. raudensis is complex and appears to involve differential energy partitioning, photosystem stoichiometry and polypeptide phosphorylation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1767, Issue 6, June 2007, Pages 789–800
نویسندگان
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