干旱区生态环境知识资源中心(Arid): 温室条件下UV-B辐射对蓝藻结皮生长和超微结构的影响

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	温室条件下UV-B辐射对蓝藻结皮生长和超微结构的影响
其他题名	Effects of UV-B radiation on growth and ultrastructures of cyanobacterial crusts under greenhouse conditions
	饶本强; 吴沛沛; 李敦海; 刘永定
来源期刊	环境科学学报
ISSN	0253-2468
出版年	2011
卷号	31 期号:3 页码:649-657
中文摘要	UV-B辐射是野外蓝藻结皮经常面临的一种环境胁迫因子.报道了温室条件下UV-B辐射对蓝藻结皮形态,生理和超微结构特征的影响.在本研究中,首先通过接种具鞘微鞘藻和爪哇伪枝藻形成初始蓝藻结皮,接着以初始蓝藻结皮为材料进行3种辐射处理:光合有效辐射,UV-B辐射+光合有效辐射和N-乙酰半胱氨酸+UV-B辐射+光合有效辐射.在各种辐射处理的第0,1,3,6,9和20天分别测定蓝藻结皮的光合活性(Fv/Fm),叶绿素a,伪枝藻素和胞外多糖含量.同时采用扫描电镜观察辐射处理下结皮的超微结构特征.此外,对结皮的表观形态如结皮颜色,厚度,干重等进行了测定.结果表明UV-B辐射对蓝藻结皮具有持续而明显的负面效应.与对照结皮相比,UV-B辐射下结皮的表观形态受到不利影响,结皮Fv/Fm被完全抑制,单位重量的叶绿素a含量和胞外多糖含量显著降低,而伪枝藻素含量并未受到UV-B辐射抑制,其含量则出现大量增加.电镜观察表明,UV-B辐射导致蓝藻结皮的超微结构遭到明显破坏,表现为藻丝体数量减少,缢缩成条索状,对沙粒的缠绕减弱等.研究还表明,N-乙酰半胱氨酸能够较好地保护UV-B辐射下结皮的光合活性,增加结皮的叶绿素a含量和胞外多糖含量,并有利于结皮表观形态的恢复.本研究探索了蓝藻结皮对UV-B辐射的响应,对于进一步理解蓝藻结皮对UV-B辐射的耐受限度以及应用蓝藻结皮进行荒漠化治理具有重要的理论与实际意义
英文摘要	UV-B radiation may be an environmental stress commonly experienced by cyanobacterial crusts growing in desert areas. Here we report the effects of UV-B radiation on the morphological and physiological changes and ultrastructural characteristics of cyanobacterial crusts. In this study, firstly the initial cyanobacterial crusts were formed by inoculating Microcoleus vaginatusGom. and Scytonema javanicum(K tz.) Born et Flah onto loose sand in Petri dishes. Then, the initial cyanobacterial crusts were exposed to three different radiation treatments as follows:photosynthetically active radiation (PAR),UV-B+PAR and N-acetylcysteine (NAC) +UV-B+PAR. On the 1st,3rd,6th,9th,12th and 20th days during the UV-B radiation experiments, photosynthetic activities (optimal quantum yield, Fv/Fm), chlorophyll a, scytonemin and exopolysaccharide (EPS) contents of the crusts were examined. Crust color, crust shape, crust thickness and crust pH as well as crust dry weight were all determined. We also observed the ultrastructure properties of the cyanobacterial crusts under PAR and UV-B+PAR treatments by means of scanning electron microscopy (SEM). The results indicated that the applied UV-B dose had long-lasting negative effects on the cyanobacterial crusts. Fv/Fm of the cyanobacterial crusts was completely inhibited by UV-B radiation, which meant UV-B radiation had evident photoinhibition effects on the crusts. Chlorophyll acontent of the crust treated with UV-B radiation was significantly lower than that of the crust under control conditions. In the case of UV-B exposure, scytonemin of the cyanobacterial crusts was not inhibited by UV-B and on the contrary UV-B induced a marked increase in scytonemin. Furthermore, the EPS content of the crust under UV-B treatment presented a significant decline as compared to the control crust (p<0.05). Obvious destruction of ultrastructures was observed from the cyanobacterial crust subjected to UV-B stress, and many changes in morphological characteristics of the crust under UV-B radiation were also detected. Further, our results showed that NAC addition could provide effective protection to the photosynthetic activity of the crust under UV-B radiation and the levels of chlorophyll aand EPS were also promoted due to NAC addition, which meant that NAC might function as an effective antioxidant and could protect the cyanobacterial crust from oxidant stress induced by UV-B radiation. The aim of this study was to discuss the responses of cyanobacterial crusts to UV-B radiation and to improve understanding of toleration restriction of the crusts against UV-B radiation, which may provide academic and practical significances for cyanobacterial crust applications in desertification control
中文关键词	蓝藻结皮 ; UV-B辐射 ; 超微结构 ; 光合活性 ; 叶绿素a ; 伪枝藻素 ; 胞外多糖 ; N-乙酰半胱氨酸
英文关键词	cyanobacterial crusts UV-B radiation ultrastructures photosynthetic activities chlorophyll a scytonemin exopolysaccharide N-acetylcysteine
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PLANT SCIENCES
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:4158673
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/226728
作者单位	中国科学院水生生物研究所, 淡水生态与生物技术国家重点实验室, 武汉, 湖北 430072, 中国
推荐引用方式 GB/T 7714	饶本强,吴沛沛,李敦海,等. 温室条件下UV-B辐射对蓝藻结皮生长和超微结构的影响[J],2011,31(3):649-657.
APA	饶本强,吴沛沛,李敦海,&刘永定.(2011).温室条件下UV-B辐射对蓝藻结皮生长和超微结构的影响.环境科学学报,31(3),649-657.
MLA	饶本强,et al."温室条件下UV-B辐射对蓝藻结皮生长和超微结构的影响".环境科学学报 31.3(2011):649-657.