Zhang Chunhui, Zhang Litao, Liu Jianguo
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.
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.
Plant Physiol Biochem. 2016 Oct;107:75-81. doi: 10.1016/j.plaphy.2016.05.029. Epub 2016 May 20.
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.
此前大多数关于雨生红球藻的研究都集中在其生长和虾青素积累方面。然而，光呼吸与虾青素积累之间的关系尚未明确。本研究的目的是探讨光呼吸在雨生红球藻虾青素积累过程中的作用。在虾青素积累过程中，当用其特异性抑制剂甲氧基羰基肟抑制光呼吸时，虾青素含量显著降低。抑制光呼吸在培养过程中并未改变干重、叶绿素含量和OJIP瞬变；然而，抑制光呼吸显著降低了光系统II的光化学活性和总的光合放氧能力。此外，光呼吸的限制与虾青素积累的减少同步发生。这些结果表明，雨生红球藻中的光呼吸途径可以加速虾青素的积累。我们推测光呼吸可通过以下方式增强虾青素积累：（i）光呼吸直接影响3-磷酸甘油酸（PGA）水平，这与雨生红球藻中虾青素的积累内在相关；（ii）光呼吸途径通过影响光合作用的暗反应间接影响PGA水平，进而导致雨生红球藻中虾青素积累的增强。
