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Factors influencing the distribution of coastal lichens Hydropunctaria maura and Wahlenbergiella mucosa 
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下载免费PDF全文 Responses to abiotic and biotic stresses that potentially drive the vertical zonation of the intertidal lichens Hydropunctaria maura, an upper littoral lichen, and Wahlenbergiella mucosa, a lower littoral lichen, were investigated in field and laboratory experiments. When transplanted, both lichens exhibited an inability to survive outside their normal vertical distribution range. W. mucosa appeared to be unable to tolerate prolonged periods of desiccation following translocation from lower to upper littoral regions, whereas H. maura was unable to survive in lower littoral zones possibly owing to increased grazing pressure. The effect of desiccation in both lichens was compared using pulse amplitude modulated chlorophyll fluorescence and infra‐red gas analysis; results indicated a more hydration‐dependent nature of W. mucosa. Photosynthetic (algal) pigments and phenolic compounds were determined in both lichen thalli, and a range of additional coastal lichens occupying a natural gradient from upper to lower shore levels. Pigment composition and concentration in both lichen thalli were similar whereas levels of phenolic compounds were up to three times higher in W. mucosa than H. maura. Pigment and phenolic concentration and composition exhibited some seasonality across 13 different lichens originating from different shore levels. Phenolic concentration increased towards the lower shore, suggesting a potential anti‐herbivory function. This marks the first study of pigments and phenolics in coastal lichen communities, and prompts further investigations on the particular physiological features of marine and maritime lichens that enable them to thrive in this extreme environment. 相似文献
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目的 探讨高脂饮食大鼠肾脏3-羟基-3甲基戊二酰辅酶A合成酶2（HMGCS2）表达及可能调控机制。方法 断乳Wistar 雄性大鼠27只分为3组：正常对照组（CON）、高脂组（HFG）、绿茶多酚（green tea polyphenols,GTPs）组（G）。CON组大鼠喂养普通饲料,HFG组及GTPs组给予高脂饲料,GTPs组同时自由摄食绿茶多酚浓度为1.6g/L水溶液。26周后测定空腹血糖（FPG）、血清胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）、高密度脂蛋白（HDL）。免疫印迹法测定肾脏HMGCS2和Sirt3蛋白表达水平。结果 与CON组比较,HFG组大鼠体重和脂肪系数升高,血清FPG、TC、TG、LDL-C/HDLC均升高,差异有统计学意义（P<0.05）;与HFG组比较,GTPs降低大鼠体重和脂肪系数,差异有统计学意义（P<0.05）,GTPs组血清FPG、TC、TG、LDL-C/HDLC均不同程度降低,差异有统计学意义（P<0.05）。与CON组比较,肾脏组织HMGCS2的表达降低,差异有统计学意义（P<0.05）;与HFG组比较,GTPs组增加肾脏HMGCS2的表达,差异有统计学意义（P<0.05）。高脂饮食、正常饮食和GTPs干预后,大鼠肾脏组织Sirt3蛋白表达差异无统计学意义。结论 高脂饮食可降低肾脏组织HMGCS2表达,绿茶多酚可逆转此效应;高脂饮食及绿茶多酚对肾脏组织HMGCS2表达的调控不经Sirt3途径。 相似文献
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INTRODUCTIONBrownalgaepolyphenol (BAP)isadistinctivenaturalproduct,anactiveorganicmatterre leasedfromnormalgrowingbrownalgaeintoseawater.TheBAPoutputfromthelivingbrownalgaeis 1g (m2 ·d) (Craigieetal.,1 964 ) .About3 7%ofdissolvedorganicmatter(DOM)inseawateralongshoreisthesecretionfromseaweedcells,andcanreach 70 %oftotalDOMinseawaterifor ganicmatterreleasedbydeadalgaeisincluded (Raganetal.,1 979) .BAP (mainlycomprisingtheyellowmatter)inseawateralongshore ,canreach 2 .5mg L (Rashida… 相似文献
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Chemical means were used to extract polyphenols from healthy brown algae collected in littoral seawater. Experiments on corrosion
of A3 steel, the time-potential curve, and polarization curve in polyphenols seawater showed stronger cathodic polarization compared
with that in common seawater. This indicates that brown algae polyphenols might feasibly be used as corrosion inhibitor in
seawater.
Contribution No. 3763 from the Institute of Oceanology, Chinese Academy of Sciences.
Project 59471054 supported by NSFC and National “Nineth Five Year” Project 96-916-04-01. 相似文献
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