TY - JOUR
T1 - Changes in the levels of ribulose-l,5-bisphosphate carboxylase/oxygenase (rubisco) in tetraedron minimum (chlorophyta) during light and shade adaptation
AU - Fisher, Tamar
AU - Shurtz-swirski, Revital
AU - Gepstein, Shimon
AU - Dubinsky, Zvy
PY - 1989/3
Y1 - 1989/3
N2 - Exponentially growing cultures of the chlorophyta Tetraedron minimum were allowed to photoadapt to low (50μmole quanta m-2s-1) and high (500μmole quanta m-2-1) irradiance levels. In these cultures, various aspects of the organization of the photosynthetic apparatus and related differences in its performance were studied.In this organism, the observed five-fold increase in pigmentation of low-light adapted cells was due to increases in the numbers of PSU's, while their sizes remained constant.Using radioimmunoassay technique, we found that high-light adapted algae had over five times more Rubisco per PSU than their low-light adapted counterparts.The high-light adapted algae also exhibited far higher (×2.3) light saturated photosynthetic rates per chl a. This increase was the result of a reduction of tau, τ, the turnover time of PS II reaction centers.We propose that the increase in Rubisco per PSU in high-light adapted algae explains the reduction in τ, which results in the higher Pmax rates per chl a in these algae.The relationship is non linear, since the increase in Rubisco per PSU was ×5.3 whereas that in PmM per chl a was only ×2.3.
AB - Exponentially growing cultures of the chlorophyta Tetraedron minimum were allowed to photoadapt to low (50μmole quanta m-2s-1) and high (500μmole quanta m-2-1) irradiance levels. In these cultures, various aspects of the organization of the photosynthetic apparatus and related differences in its performance were studied.In this organism, the observed five-fold increase in pigmentation of low-light adapted cells was due to increases in the numbers of PSU's, while their sizes remained constant.Using radioimmunoassay technique, we found that high-light adapted algae had over five times more Rubisco per PSU than their low-light adapted counterparts.The high-light adapted algae also exhibited far higher (×2.3) light saturated photosynthetic rates per chl a. This increase was the result of a reduction of tau, τ, the turnover time of PS II reaction centers.We propose that the increase in Rubisco per PSU in high-light adapted algae explains the reduction in τ, which results in the higher Pmax rates per chl a in these algae.The relationship is non linear, since the increase in Rubisco per PSU was ×5.3 whereas that in PmM per chl a was only ×2.3.
KW - Photoadaptation
KW - Photosynthesis
KW - Phytoplankton
KW - Rubisco
KW - Tetraedron minimum
UR - http://www.scopus.com/inward/record.url?scp=0000636210&partnerID=8YFLogxK
U2 - 10.1093/oxfordjournals.pcp.a077733
DO - 10.1093/oxfordjournals.pcp.a077733
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AN - SCOPUS:0000636210
SN - 0032-0781
VL - 30
SP - 221
EP - 228
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
IS - 2
ER -