摘要
紫球藻 (Porphyridiumsp .)是一种海水单细胞红藻 ,是多种天然产物的来源。在其培养繁殖过程中 ,能够合成藻胆蛋白、高不饱和脂肪酸、硫酸酯多糖等生物活性物质 ,具有广阔的应用前景。盐胁迫会导致紫球藻的结合态多糖浓度的增加 ,由此可能产生相应的耐盐性的提高 ,并有利于对其他逆境的适应。该项研究采用外加紫球藻多糖或采用盐逆境诱导紫球藻多糖的积累 ,然后解除盐逆境的胁迫的方法获得多糖含量有显著提高的紫球藻试材 ,再给与其他的逆境 :如光抑制 ,低温处理 ,并测定主要的生理生化参数。试验结果表明 ,外加 0 .0 5 %紫球藻多糖的藻细胞光合效率 ,在光抑制条件下 ,低于不加多糖的对照 ,但在低温 ( 4℃ )时 ,高于对照。外加多糖对PSⅡ没有显著影响。紫球藻在去盐后的 48h恢复培养时间内 ,多糖的含量以及光抑制和低温条件下的光合效率都逐渐恢复到对照的水平。但是 ,去盐恢复培养的紫球藻PSⅡ效率在光抑制条件下却高于加盐及未加盐的两种对照 ,显示盐诱导的紫球藻多糖可能增加了PSⅡ对光抑制的忍耐程度。
In this study,the responses of Porphyridium sp.cells with salt-elevated bound polysaccharide to the stress of high proton flux density (HPFD) or chilling temperature (4 ℃) was studied in order to evaluate possible biological roles of the induced polysaccharides under environmental stresses. Addition of 0.05% polysaccharides to the Porphyridium sp.culture caused the photosynthetic activity decreased under HPFD but increased under chilling temperature (4 ℃) compared to control (culture without external addition of polysaccharide). The PSⅡ efficiency (Fv/Fm) decline was not significantly affected with the exogenous polysaccharide. Within 48 h after removal of salt from the cultures,both photosynthetic activity of the salt pre-treated cells measured under HPFD and chilling temperature (4 ℃) and bound polysaccharide content returned to the levels of un-treated cells. However,the PSⅡ efficiency of the recovery cultures measured under HPFD still kept at a higher level,especially after 6 hours,compared with control and salt treated cultures,suggesting that the high polysaccharide content induced by the salt stress may enhance PSⅡ tolerance to high photon flux density.
出处
《广西植物》
CAS
CSCD
北大核心
2004年第2期166-173,共8页
Guihaia
关键词
紫球藻
盐胁迫
多糖
光抑制
低温
Porphyridium sp.
salt stress
polysaccharide
photoinhibition
chilling temperature
