The role of photorespiration during astaxanthin accumulation in Haematococcus pluvialis (Chlorophyceae).
Most previous studies on Haematococcus pluvialis have been focused on growth and astaxanthin accumulation. However, the relationships between photorespiration and astaxanthin accumulation have not been clarified. The purpose of this study was to examine the role of photorespiration during the process of astaxanthin accumulation in H. pluvialis. During astaxanthin accumulation, the astaxanthin content was reduced significantly when photorespiration was inhibited by its specific inhibitor, carboxymethoxylamine. The inhibition of photorespiration did not change the dry weight, chlorophyll content and OJIP transients during the incubation; however, the inhibition of photorespiration significantly decreased the photochemistry of photosystem II and total photosynthetic O2 evolution capacity. Moreover, the restriction in photorespiration was synchronized with a decrease of astaxanthin accumulation. These results suggest that the photorespiratory pathway in H. pluvialis can accelerate astaxanthin accumulation. We speculate that photorespiration can enhance astaxanthin accumulation in the following ways: (i) photorespiration directly affects the glycerate-3-phosphate (PGA) level, which is intrinsically related to the accumulation of astaxanthin in H. pluvialis; (ii) the photorespiratory pathway indirectly affects the PGA level by effecting the dark reactions of photosynthesis, which then results in the enhancement of astaxanthin accumulation in H. pluvialis.
National & Local Joint Engineering Laboratory of Ecological Mariculture, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Chunhui
C
Zhang
National & Local Joint Engineering Laboratory of Ecological Mariculture, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; National-Local Joint Engineering Research Center for Haematococcus pluvialis and Astaxanthin Products, Yunnan Alphy Biotech Co., Ltd., Chuxiong 675012, PR China.
Litao
L
Zhang
National & Local Joint Engineering Laboratory of Ecological Mariculture, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; National-Local Joint Engineering Research Center for Haematococcus pluvialis and Astaxanthin Products, Yunnan Alphy Biotech Co., Ltd., Chuxiong 675012, PR China. Electronic address: jgliu@qdio.ac.cn.
Jianguo
J
Liu
D018533:Biomass; D019069:Cell Respiration / Q000528:radiation effects; D048430:Cell Shape / Q000528:radiation effects; D002734:Chlorophyll / Q000378:metabolism; D000460:Chlorophyta / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D005453:Fluorescence; D008027:Light; D010101:Oxygen Consumption / Q000528:radiation effects; D045332:Photosystem II Protein Complex / Q000378:metabolism; D013696:Temperature; D024341:Xanthophylls / Q000378:metabolism
D045332:Photosystem II Protein Complex; D024341:Xanthophylls; D002734:Chlorophyll; C005948:astaxanthine
Astaxanthin accumulation; Haematococcus pluvialis; Photorespiration; Photosynthesis