Untitled - 中国植物生理与分子生物学学会

Varieties of photosynthetic parameters of Porphyra yezoensis
Ueda during dehydration and rehydration
Guangce Wang, Fang Yang, Apeng Lin, Zhangfan Chen, Baoyu Zhang,
Baicheng Zhou
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of
Sciences, Qingdao 266071, China
Porphyra yezoensis Ueda is one of the most important economic seaweeds. Living in the intertidal
zones, P. yezoensis experiences dehydration and re-hydration regularly, which possesses significant
effects on its physiological processes. To investigate their influences on the photosynthetic
performance of P. yezoensis, in this paper, the photosynthetic data of P. yezoensis during dehydration
and re-hydration was acquired with PAM fluorometer. Under the same PAR (Photosynthetically
Active Radiation), the values of ETR (II) (the relative electron transport rate of PS II) and Y (II) (the
photochemical yield of PS II in the light) of the samples measured in air increased obviously when
AWC(absolute water content) dropped from 100% to 71%, while the values of the sealed samples
decreased directly during dehydration, showing that P. yezoensis can directly utilize CO2 in air
during light dehydration. Furthermore, the relative transcripts level of rbcL was investigated at
different desiccation stages with Real-time quantitative PCR. It can be deduced that the level of the
relative quantification transcript of rbcL was up-regulated to respond to severe dehydration,
preparing the thalli for a quick start in the process of re-hydration, which was a unique mechanism to
withstand severe water loss.
Key words: Porphyra yezoensis; Rubisco; desiccation; relative quantification of transcript levels;
mRNA; CO 2 utilization
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