Increased toxicity of Karenia brevis during phosphate limited growth: ecological and evolutionary implications.
Increased toxicity of Karenia brevis during phosphate limited growth: ecological and evolutionary implications.
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DOI：
10.1371/journal.pone.0058545
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Litaker RW
中科院分区：
文献类型：
--
作者：
Hardison DR;Sunda WG;Shea D;Litaker RW
Karenia brevis是墨西哥湾的主要有毒赤潮藻种。它产生强效神经毒素（短杆菌毒素[PbTxs]），对人类和动物健康、当地经济和生态系统功能产生负面影响。现场测量表明，细胞内短尾孢毒素含量从1-68 pg/细胞不等，但这种变化的来源是不确定的。在许多藻类物种中观察到营养限制和菌株间差异导致的细胞毒性增加。本研究探讨了生长速度的P限制对来自不同地理位置的五个短凯伦藻菌株细胞毒素浓度的影响。选择磷是因为墨西哥湾藻类生长的区域磷限制的证据。根据分离株的不同，P-限制细胞的PbTx/细胞比P-充满细胞高2.3- 7.3倍。在P-充分的细胞中，与短尾藻毒素相关的细胞碳百分比（%C-PbTx）为0.7 - 2.1%，但在P-限制下增加到1.6-5%。由于PbTxs是有效的抗放牧化合物，因此增加对PbTxs的投资应能提高营养有限生长期间的细胞存活率。%C-PbTx是负相关的营养丰富和P-有限的文化的所有菌株的比生长速率。这种反向关系是一致的碳投资PbTxs和其他放牧防御之间的进化权衡，和C投资的增长和繁殖。在水生环境中，营养供应和放牧压力往往在不同的时间和空间尺度上变化，这种权衡将是选择性的优势，因为它会导致增加净人口增长率。在本研究中观察到的PbTx/细胞值的变化可以解释在该领域中观察到的值的范围，包括在N限制下未观察到的最高值。这些结果表明，磷限制是一个重要的因素，调节细胞毒性和不利影响，至少在一些K。短枝花
Karenia brevis is the dominant toxic red tide algal species in the Gulf of Mexico. It produces potent neurotoxins (brevetoxins [PbTxs]), which negatively impact human and animal health, local economies, and ecosystem function. Field measurements have shown that cellular brevetoxin contents vary from 1–68 pg/cell but the source of this variability is uncertain. Increases in cellular toxicity caused by nutrient-limitation and inter-strain differences have been observed in many algal species. This study examined the effect of P-limitation of growth rate on cellular toxin concentrations in five Karenia brevis strains from different geographic locations. Phosphorous was selected because of evidence for regional P-limitation of algal growth in the Gulf of Mexico. Depending on the isolate, P-limited cells had 2.3- to 7.3-fold higher PbTx per cell than P-replete cells. The percent of cellular carbon associated with brevetoxins (%C-PbTx) was ∼ 0.7 to 2.1% in P-replete cells, but increased to 1.6–5% under P-limitation. Because PbTxs are potent anti-grazing compounds, this increased investment in PbTxs should enhance cellular survival during periods of nutrient-limited growth. The %C-PbTx was inversely related to the specific growth rate in both the nutrient-replete and P-limited cultures of all strains. This inverse relationship is consistent with an evolutionary tradeoff between carbon investment in PbTxs and other grazing defenses, and C investment in growth and reproduction. In aquatic environments where nutrient supply and grazing pressure often vary on different temporal and spatial scales, this tradeoff would be selectively advantageous as it would result in increased net population growth rates. The variation in PbTx/cell values observed in this study can account for the range of values observed in the field, including the highest values, which are not observed under N-limitation. These results suggest P-limitation is an important factor regulating cellular toxicity and adverse impacts during at least some K. brevis blooms.
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影响因子：
4
作者：
Howarth, RW;Billen, G;Zhu, ZL
通讯作者：
Zhu, ZL
DOI：
10.1007/978-3-540-32210-8_18
发表时间：
2006-01-01
期刊：
ECOLOGY OF HARMFUL ALGAE
影响因子：
--
作者：
Graneli, E.;Flynn, K.
通讯作者：
Flynn, K.
影响因子：
2.1
作者：
Cohen, Jonathan H.;Tester, Patricia A.;Forward, Richard B., Jr.
通讯作者：
Forward, Richard B., Jr.
影响因子：
2.9
作者：
Adolf, Jason E.;Bachvaroff, Tsvetan R.;Place, Allen R.
通讯作者：
Place, Allen R.
影响因子：
2.9
作者：
Hardison, D. Ransom;Sunda, William G.;Tester, Patricia A.
通讯作者：
Tester, Patricia A.