温度对不同穗重型水稻叶片保护酶活性及同工酶表达的影响

通过人工控温,对不同穗重型品种叶片的过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化歧化酶(SOD)的酶活性及同工酶表达进行研究,结果表明:重穗型品种Ⅱ优162、冈优527在适温(24℃)、次高温(29℃)和高温(32℃)下,叶片中的3种保护酶活性都呈上升的趋势;而中穗型品种D优68和轻穗型品种E优540,在高温下其3种保护酶活性下降。从同工酶表达看,SOD的同工酶谱带在不同穗重型品种间无明显差异,且随温度的升高而减弱。CAT表达则在重穗型与中穗和轻穗型品种间有明显不同,特别是高温胁迫(38℃)下,中穗型和轻穗型品种谱带C1消失,而重穗型品种则产生1条新的CAT谱带C0。POD表达研究发现,不仅穗重型间,且在同一类型的品种间也存在差异性,但前者间的差异显著大于后者,表明不同穗重型可能存在不同的高温应答机制。

泥蚶(Tegillarca granosa)个体发育过程中同工酶基因表达与调控的研究

采用不连续垂直聚丙烯酰胺凝胶电泳法,对泥蚶(TegillarcagranosaLinnaeus)19个发育阶段的ADH、LDH、EST、IDH、ALP、MDH、GDH、POD、ATPase和ME等10种同工酶的基因表达进行检测分析。结果表明,泥蚶在个体发育过程中随着机体分化和生理活动的改变,同工酶基因的表达呈现出显著的时序变化。在10种酶中,LDH和ATPase两种酶的所有酶带及EST、MDH和ME等的部分酶带在各个发育阶段持续表达,其他酶带只出现在发育阶段的某一或某些阶段,并且表现出了与泥蚶营养方式、代谢形式等生理活动的关联性。在泥蚶的个体发育阶段过程中,IDH、MDH、GDH、ME、ALP等5种酶在32细胞期表达的酶带数剧增,因此32细胞期可能是合子基因表达启动的时间;ADH、EST、LDH、MDH、GDH、ME等6种酶在泥蚶的附着变态期酶带大幅减少或产生新酶带,可能与泥蚶附着期运动方式、代谢强度及生活环境的改变有关。

γ-氨基丁酸对低氧胁迫下甜瓜幼苗抗氧化酶活性及表达的影响

采用营养液水培方法，研究低氧胁迫下外源GABA对甜瓜幼苗抗氧化酶（SOD、POD、CAT和APX）活性和同工酶表达的影响，采用实时荧光定量PCR方法检测幼苗根系抗氧化酶的基因表达特性。结果表明，低氧胁迫处理下，幼苗根系和叶片抗氧化酶活性和同工酶表达均高于对照，且根系CmSOD、CmPOD1、CmPOD2、CmCAT、CmAPX基因均上调表达；低氧胁迫下外源GABA处理显著提高幼苗根系和叶片SOD、CAT和APX活性以及同工酶表达，且根系CmSOD、CmCAT、CmAPX基因相对表达量在0.5~1 d迅速提高并达到最大值，且增加幅度高于低氧胁迫处理。由此可知，GABA通过促进根系抗氧化酶基因快速大量表达，提高抗氧化酶活性和同工酶的表达量，从而缓解低氧胁迫对甜瓜幼苗的伤害。

萍乡显性核不育水稻不育株与可育株同工酶比较分析

对萍乡显性核不育水稻纯合不育株、杂合不育株和隐性可育株幼穗发育期的叶片、幼穗和花药中3种同工酶表达进行了比较分析,结果表明:叶片中,不育株(纯合与杂合)与可育株的酯酶(EST)、过氧化物酶(POD)、细胞色素氧化酶(COD)的同工酶酶谱未见差异,且在幼穗发育的不同时期也基本相同;幼穗中,不育株(纯合与杂合)与可育株的EST、POD、COD的同工酶酶谱在雌雄蕊形成期存在差异,与可育株的同工酶酶谱相比,不育株除在谱带的显色速度、颜色和带宽上存在差异外,在谱带数及其分布未见差异;在单核期花药中,不育株(纯合与杂合)比可育株多1条EST、少2条POD和2条COD同工酶带,在三核期也呈上述特征。表明水稻显性核不育基因在叶片中不表达、幼穗中部分表达和花药中充分表达,水稻显性核不育基因表达具有组织的时空和特异性。花药发育过程中基因表达程序的扰乱是引起花粉败育的最主要的原因。

Analysis of Gene Expression of Seven Isoforms of ADP-glucose Pyrophosphorylase in Rice Endosperm under Different Temperature Conditions

[Objective] This study aimed to analyze the effects of temperature on the expression of AGPase isoform genes in rice endosperm during milk stage. [Method] Different temperature treatments （33 and 25 ℃ of daily mean temperature for high and normal temperature treatments, respectively） and the real-time fluorescence quantitative PCR （ FQPCR） were used to analyze the expression patterns of seven isoforms （AGPS1, AGPS2a, AGPS2b, AGPL1, AGPL2, AGPL3 and AGPL4） of ADPglucose pyrophosphorylase （AGPase） which was the key enzyme in starch synthesis and metabolism in rice endosperm of two rice varieties Teqing and Thai Fragrant Rice. [Result] The AGPase isoforms AGPS2b, AGPL2 and AGPL3 had much higher expression than the other four isoforms, thus they were thought to be the main expression patterns of AGPase in rice endosperm. The relative expressions of AGPL2 was the highest among all the isoforms. The relative expressions of AGPS2b, AGPL2 and AGPL3 were higher in the normal temperature treatment than in the high temperature treatment in both rice varieties. The relative expression of the three enzyme genes in milk stages in Teqing was higher than those in Thai Fragrant Rice under different temperature treatments. [Conclusion] This study provides a theoretical basis for further use of molecular biology techniques to cultivate stable high-quality rice varieties.

Tissue Expression and Stock Variation of Isozymes of Stone Flounder(Kareius bicoloratus)

Tissue expression and stock variation of isozymes of stone flounder （Kareius bicoloratus） were analyzed with horizontal starch gel electrophoresis. For the fourteen enzymes assayed, 31 loci were recorded. The results indicated that all the isozymes examined were obviously tissue-specific. The expressions of SOD＊, GDH＊, G3PDH-2＊ and ADH-2＊ were detected only in liver, SDH-1＊, MDH-1＊ and ADH-1＊ only in muscle, and LDH-B＊ and LDH-C＊ only in eyes. In comparison, MDH-2＊, GPI-3＊ and SDH-2＊ were detected in all tissues examined. Other loci examined were detected in a variety of tissues. Muscle and liver were selected to detect the isozyme variation of the two geographic stocks of Qingdao and Weihai, Shandong Province, China. The percentages of polymorphic loci （P0.99） were 29.17% and 25.00%, the observed heterozygosities （H0） were 0.028 ±0.014 and 0.040 ± 0.019, and the expected heterozygosities （He） were 0.039±0.017 and 0.052±0.022 in Qingdao and Wethai stock, respectively. The coefficient of gene differentiation （Fst） and genetic distance （D） between the two stocks was 0.012 and 0.0011, respectively, indicating that the genetic differentiation is low between them. Compared with other species of Pleuronectiformes, both the percentage of polymorphic loci and the mean heterozygosity ofK. Bicoloratus were at a middle level.