以非洲菊品种'玲珑'为材料,利用RT-PCR技术克隆获得一条CDS长为519 bp的SOD基因(GenBank ID:MH708534.1).利用生物信息学手段分析了该基因及其编码蛋白的序列特征,并利用实时荧光定量PCR(qRT-PCR)技术分析了该基因在3种激素(100μmol/L IAA、SA和GA3)和3种非生物胁迫(200 mmol/L NaCl盐胁迫、30％PEG模拟干旱和4℃低温处理)下的表达模式.结果显示:该基因可编码分子量为19203.85、等电点(pI)为7.93、无信号肽及跨膜结构的稳定亲水蛋白.该蛋白含有典型Sod-Fe-C保守结构域,在141-148位氨基酸之间含有一个MnSOD特征序列(DVWEHAYY),因此命名为GjMnSOD.Wolf Psort预测结果显示GjMnSOD定位于线粒体.GjMnSOD与刺苞菜蓟MnSOD相似性最高(为93.86％)且在进化上亲缘关系最近.qRT-PCR结果显示:GjMnSOD的表达受IAA、GA3、SA、盐胁迫和低温显著抑制;在干旱胁迫下,GjMnSOD的表达呈"先降后升"的表达趋势,于处理4 h后显著高于对照.研究结果表明GjMnSOD参与非洲菊对多种逆境胁迫的响应,尤其在非洲菊应答干旱胁迫过程中发挥重要作用.

Qingliu County in Fujian is one of the most important gerbera producing areas in China .Recently ,the root rot disease is becoming epidemic and serious in the county .The present study sampled and isolated pathogenic fungi from the plant roots that were infected by the disease .The morphology and molecular identification analyses on the samples indicated that the pathogens , Phytophthora cryptogea , Fusarium oxysporum , Colletotrichum gloeosporioides and F .solani were likely the culprits ,with P .cryptogeaand F .oxysporum being most numerous . After a Koch's theorem verification , P .cryptogea was further identified as the fungus that caused the root rot disease on gerbera in Qingliu County .The information is to be used for selecting control method and in further studies on the pathogen as well as its antagonistic microorganisms for bio-control on the disease .

Effects of Piriformospora indica treatment on seed germination and seedling grow th of Dongbi longan (Dimocarpus longan) were investigated .After a treatment with P .indica ,the germination rate of the longan seeds stored at room temperature for three days increased significantly at P＜0.01. Two months after sowing ,the root count and height of the seedlings significantly increased as well (P＜0.01) ,and the weights of branched roots ,main roots ,above-ground and entire plantlet all significantly increased (P＜0.05) .The average length of main roots on the treated seedlings was shorter than that on control ,but not significantly different .Nor was there any significant difference on leaf count .It appeared that by treating the seeds with P . Indica the germination rate and seedling growth of Dongbi longan could be improved .

[目的]揭示不同激素和非生物逆境处理下非洲菊SOD活性变化趋势.[方法]对非洲菊进行ABA、SA、高盐、干旱(PEG模拟)和低温处理,测定处理前后SOD酶活性.[结果]在处理时间内,ABA对非洲菊SOD活性没有显著影响,SA则极显著抑制SOD活性.在高盐处理下,非洲菊SOD活性表现出先升高后降低的趋势;PEG模拟干旱处理下,SOD活性极显著下调(P<0.01).低温处理极显著抑制SOD活性(P<0.01),SOD活性变化趋势为先降低再升高.[结论]非洲菊SOD活性在不同逆境处理下表现出不同的变化趋势;该研究可为揭示SOD在非洲菊抗逆防御反应中的作用规律奠定基础.