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长囊水云(Ectocarpus siliculosus)是一种重要的海洋褐藻,是褐藻研究的模式生物.以其叶绿体全基因组序列为基础,对密码子使用特征进行分析.结果显示,叶绿体基因组的GC尤其是GC3值较低,分别为31.8％和17.32％,偏向使用以A或T碱基结尾的密码子;全基因组具有较小的有效密码子数(ENC)值和较高的密码子适应指数(CAI)值,表明其具有较高的同义密码子使用偏性;密码子使用特征受到基因表达水平上的自然选择以及基因碱基组成中性突变的双重影响,其中选择的作用对高表达基因密码子使用偏性的影响比较突出,而突变是低表达基因密码子使用偏性的主要影响因素.另外,首次确定UUU,GUU,UCA等12个密码子为长囊水云叶绿体基因组的最优密码子. 相似文献
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Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments,and consequently may have highly effi cient ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco)activity for carbon assimilation.In our study,we cloned the full-length Rubisco gene from S.japonica(SJ-rbc).It contained an open reading frame for a large subunit gene(SJ-rbcL)of 1 467 bp,a small subunit gene(SJ-rbcS)of 420 bp,and a SJ-rbcL /S intergenic spacer of 269 bp.The deduced peptides of SJ-rbcL and SJ-rbcS were 488 and 139 amino acids with theoretical molecular weights and isoelectric points of 53.97 kDa,5.81 and 15.84 kDa,4.71,respectively.After induction with 1 mmol/L isopropyl-β-Dthiogalactopyranoside for 5 h and purifi cation by Ni 2+ affi nity chromatography,electrophoresis and western blot detection demonstrated successful expression of the 55 kDa SJ-rbcL protein.Real-time quantitative PCR showed that the mRNA levels of SJ-rbcL in gametophytes increased when transferred into normal growth conditions and exhibited diurnal variations: increased expression during the day but suppressed expression at night.This observation implied that Rubisco played a role in normal gametophytic growth and development.In juvenile sporophytes,mRNA levels of SJ-rbcL,carbonic anhydrase,Calvin-BensonBassham cycle-related enzyme,and chloroplast light-harvesting protein were remarkably increased under continuous light irradiance.Similarly,expression of these genes was up-regulated under blue light irradiance at 350 μmol/(m 2·s).Our results indicate that long-term white light and short-term blue light irradiance enhances juvenile sporophytic growth by synergistic effects of various photosynthetic elements. 相似文献
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为研究极北海带幼苗在温度条件下的生理、生态适应性,作者开展极北海带幼苗(1~15 cm)在不同温度下的相对生长速率以及光系统II最大荧光产量(Fv/Fm)、光合作用和呼吸作用等生长和生理响应研究,探讨其最大表观光合速率、饱和光强(Isat)和光补偿点(Ic)等参数。得出以下结论:(1)极北海带幼苗生长的适宜温度范围为9~15℃,温度上限为21℃;(2)极北海带幼苗在21℃胁迫24h以上,可导致其光合系统II产生不可逆损伤;(3)叶片长度对其幼苗的Fv/Fm有显著影响,较大的幼苗相对耐受高温;(4)在5~17℃范围内,极北海带幼苗Ic为4.6~15.4μmol/(m2·s), Isat为52.4~100.3μmol/(m2·s);(5)低温条件下,极北海带幼苗可适应更弱的光照,但相对不耐强光;较大的极北海带幼苗则相对耐强光,其适应更弱光照。本研究结果可为极北海带的人工育苗及养殖提供参考。 相似文献
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采用掌状海带(Laminariadigitata)幼苗为实验材料,研究了不同温度(3、8、13、18℃)对其生长、抗氧化系统及叶绿素荧光参数的影响。测定主要参数有:相对生长速率(RGR)、可溶性蛋白、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛(MDA)、PSII最大荧光产量(Fv/Fm)、最大相对电子传递速率(r ETRmax)结果表明:(1)掌状海带幼苗的RGR在13℃下达最大值,与3℃处理组对比呈显著性差异(P0.05)。(2)3℃处理4 h或18℃处理36 h对掌状海带幼苗SOD、CAT活性有显著影响。(3)3℃培养条件下,掌状海带幼苗的Fv/Fm、r ETRmax值显著低于对照组(13℃);18℃处理组的Fv/Fm值随着胁迫时间的延长而降低,其r ETRmax值在胁迫4 h后达最大;处理24 h,8℃处理组的r ETRmax值显著高于其他处理组。 相似文献
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Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate （SGR） of 10.47 at 25℃/40 μmol m^-2s^-1. Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 μm in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative cells could still divide actively in the algal tissues. 相似文献
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Effect of temperature and irradiance on the growth and reproduction of Enteromorpha prolifera J. Ag. （Chlorophycophyta, Chlorophyceae） 总被引：1，自引：0，他引：1
Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate (SGR) of 10.47 at 25°C/40 μmol m-2s-1. Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 μm in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative ceils could still divide actively in the algal tissues. 相似文献
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对羊栖菜(Hizikia fusiformis (Harv) Okamura)养殖中常见的3个品系进行了DNA指纹分析及遗传变异的研究,构建了其遗传指纹图谱,分析了不同种群的遗传关系,为羊栖菜的种质鉴定及选育提供了理论依据.运用RAPD分子标记技术,对5个羊栖菜的种群中共125个个体进行了分析,从300个引物中筛选出12条随机扩增引物共扩增135个位点,多态位点比率为84.4%.从中选择了4个多态性位点,构建了DNA指纹图谱.相关结果对羊栖菜遗传选育和种质鉴定等有参考价值. 相似文献
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