摘要
为了探讨海黍子的外源无机碳利用机制,本文以光合放氧为指标研究了不同p H(6.5、8.0和9.5)及添加不同抑制剂(AZ、EZ和DIDS)对海黍子光合固碳特性的影响。结果显示,随着外源碳浓度的增加,海黍子的光合放氧速率逐渐增加,随着p H的升高,藻体的最大光合作用速率(Vmax)逐渐降低,而无机碳半饱和常数(K0.5)逐渐升高。碳酸酐酶抑制剂acetazolamide(AZ)、6-ethoxyzolamide(EZ)及阴离子交换蛋白抑制剂4,4’-diisothiocyano-stilbene-2,2’-disulfonate(DIDS)对海黍子的光合固碳速率均有强烈的抑制作用。以上结果说明,海黍子不仅对海水中的CO2具有较高的亲和力,而且还可以利用海水中的HCO3-作为光合作用的无机碳源,且对HCO3-的吸收具备两条途径:既可以通过胞外碳酸酐酶催化转化为CO2后进入细胞,也可通过阴离子交换蛋白直接吸收海水中的HCO3-。
The inorganic carbon utilization in Sargassum muticum was investigated under different pH （6.5, 8.0 and 9.5） and different inhibitors （AZ, EZ and DIDS）. The results showed that photosynthetic 02 evolution rates in S. muticum increased gradually with increasing exogenous inorganic carbon concentration. Vmax declined while K0.5 rose remarkably along with increasing pH level. Both of carbonic anhydrase inhibitors [acetazolamide （AZ） or ethoxyzolamide （EZ）] and anion exchanger inhibitor [4,4＇-diisothiocyano-stilbene-2,2＇-disulfonate （DIDS）] notably suppressed photosynthetic 02 evolution rates of S. muticum. These results suggested that S. muticum not only had a high affinity for CO2, but also could use HCO3- as a source of Ci for photosynthesis. Moreover, two ways to use HCO3- were found in this alga, one was transforming HCO3 into CO2 through carbonic anhydrase outside of the cell membrane, and the other was absorbing HCO3 directly by anion-exchange orotein.
出处
《植物生理学报》
CAS
CSCD
北大核心
2015年第5期679-685,共7页
Plant Physiology Journal
基金
国家自然科学基金(41376129)
海洋公益性行业科研专项经费项目(201305021
201405040
201505022和201305005)
青岛市市南区科技发展资金项目(2013-12-005-SW)
关键词
海黍子
光合固碳
AZ
EZ
DIDS
Sargassum muticum
photosynthetic carbon fixation
AZ
EZ
DIDS
