浮游动物论文：浮游动物对产毒微囊藻以及微囊藻产毒的影响 隧道烘箱验证方案
横向切片【中文摘要】蓝藻毒素的产生和释放是蓝藻水华的主要危害之一。浮游动物控藻作为生物控藻的主要手段之一,在其控藻的同时,对产毒微囊藻及微囊藻产毒会产生何种影响近年来逐渐受到关注,其中有研究认为浮游动物能够诱导蓝藻产毒量变化。本研究将野外调查与实验室试验结合研究浮游动物捕食胁迫对产毒微囊藻及微囊藻产毒的影响。野外调查结果表明,调查区域产毒微囊藻在水体中常年出现,数量变化范围为2.41×102-3.20×105cells/ml。产毒微囊藻占微囊藻的比例冬季较低,春季最高,最高可达39.73%,水华暴发后这一比例显著下降,最低仅为1.53%。同时枝角类数目也是在春季达到高峰最高时为3210 int./L,而在有蓝藻水华的秋夏季以及温度较低的冬季数目都很低。相关性分析显示水体中枝角类的捕食强度提升导致产毒微囊藻占微囊藻的比例显著提升。首次利用RT-qPCR技术检测大型溞胁迫对产毒铜绿微囊藻PCC 7806微囊藻毒素相关基因转录水平的影响,结果显示大型溞胁迫可以导致铜绿产毒微囊藻PCC 7806产毒相关基因mcyB, mcyD, mcyH转录水平上调,且利用ELISA测得的微囊藻毒素含量变化与基因转录水平变化相吻合,证实了RT-qPCR方法可以较好地从基因转录水平反映微囊藻产毒变化情况。龄期为5天的成体大型溞可导致OD680为0.032的铜绿微囊藻PCC 7806产毒相关基因mcyB, mcyD, mcyH转录水平上调,但无法诱导OD680为0.094的铜绿微囊藻PC诺基亚cdma>复印机碳粉
C 7806产毒相关基因转录水平上调,且微囊藻毒素含量变化与产毒相关基因转录变化相吻合。这一结果表明大型溞胁迫导致铜绿产毒微囊藻PCC7806产毒相关基因转录水平上调与铜绿微囊藻的浓度有关。龄期为1天的幼体大型溞无法诱导OD680为0.032的铜绿微囊藻PCC 7806产毒相关基因mcyB, mcyD, mcyH转录水平上调,但龄期为5天和10天的成体大型溞均可诱导OD680为0.032的铜绿微囊藻PCC 7806产毒相关基因转录水平上调,且龄期为10天的成体大型溞在实验进行第1天即可诱导产毒相关基因转录水平上调,同时微囊藻毒素含量变化与产毒相关基因转录变化相吻合。这一结果表明大型溞胁迫导致铜绿产毒微囊藻PCC 7806产毒相关基因转录水平上调与大型溞的龄期有关。通过野外调查及实验室研究我们发现,微囊藻毒素是微囊藻等浮游藻类抵抗浮游动物捕食的重要诱导防御手段,但这种诱导防御具有阈值特性,只有浮游动物的胁迫强度达到一定强度这种诱导防御才会发生,且呈现胁迫强度越大诱导防御也越强烈的趋势。
【英文摘要】It is well known that one of the most harmful effects of cyanobacterial blooms is the production of cyanotoxins. Recently the interactions between zooplankton and Microcystis species have been extensively concened. Some studies have revealed that zooplankton can cause the change of toxin production in Microcystis. In this paper th
e abundance of the potential microcystin-producing Microcystis (mcyB-containing Microcystis) in a small pool was monitored using the Real-time PCR, and the relationships between the potential microcystin-producing Microcystis and zooplankton or nutrients were studied. Meanwhile, targeting on the transcriptions of genes responsible for microcystin synthesis under the stress of Daphnia, the response of Microcystis aeruginosa PCC7806 via the regulation of microcystin production toward the different stages of Daphnia were studied using the RT-qPCR.The results showed that the mcyB-containing Microcystis appeared in the studied area all the year and the concentrations of the mcyB-containing Microcystis ranged from 2.41×102 to 3.20×105 cells/ml. The percentage of mcyB-containing Microcystis cells number in total Microcystis was lower in winter and highest up to 39.73% in spring but went down to the lowest as 1.53% after the Microsystis bloom. It was shown that the percentage of mcyB-containing Microcystis in total Microcystis had a positive linear relationship with the number of cladocerans, implying that the stress of cladocerans can induce the presence of toxic Microcystis in the bloom.The RT-qPCR was firstly used to study the change of transcription regulation of ge
nes responsible for microcystin synthesis in Microcystis aeruginosa PCC7806 under the stress of Daphnia. The result showed that the grazing stress from D. manga could increase transcript levels of mcyB, mcyD and mcyH as the inducible defence of M. aeruginosa PCC7806. The change of microcystin content measured with ELISA agreed with the change of transcripts levels of mcy, therefore the RT-qPCR approach can suitably represent the change of microcystin content from genetic view.D. manga with five days old could cause the increased transcripts levels of mcyB, mcyD and mcyH of M. aeruginosa PCC7806 with OD680 as 0.032, but could not cause the similar change of M. aeruginosa PCC7806 at 0.094 of OD680. The change of microcystin content measured with ELISA also agreed with that of transcript levels of mcy. The increased transcripts levels of mcy of M. aeruginosa PCC7806 could not be observed by using the neonate D. magna with one day old, but could be caused by the five days old juvenile and ten days old adult D. magna grazing, and the change of microcystin content measured with ELISA also agreed with the change of transcripts levels of mcy. The above results suggested that the increased transcripts levels of mcy of M. aeruginosa PCC7806 caused by the gra
工程塑料改性技术zing from D. magna were related to both Microcystis concentration and the age of D. magna.This result implied that microcystin produced by Microcystis is a very important induced defense of Microcystis against the grazing stress from zooplankton, but this induced defense has some threshold trait. The induced defense happens only when the grazing stress from zooplankton reaches the threshold, and the stronger grazing stress can cause the stronger induced defense.
大屏幕控制器
豫公网安备41160202000603
站长QQ:729038198
关于我们
投诉建议