花色素苷生物合成与分子调控研究进展

花色素苷是决定植物花色的主要色素,其生物合成是目前研究得最为清楚的植物次生代谢途径之一。花色素苷的生物合成主要在3个关键酶F3H,F3′H和F3′5′H的作用下形成3个分支,最终分别生成橙色到砖红色的天竺葵素糖苷、红色的矢车菊素糖苷和蓝色到紫色的飞燕草素糖苷。F3′H、F3′5′H和DFR基因是利用遗传转化引入花卉植物原本缺乏的花色代谢途径的关键基因。花色素苷合成结构基因的转录调控是目前研究的热点,进行调控的转录因子主要包括两大类相互作用的bHLH和MYB转录因子;花色素苷合成的转录调控机理,包括bHLH和MYB两类因子之间的相互作用,以及它们对结构基因顺式元件的识别与结合,已经阐述得比较清楚。另外,对于一些处于bHLH和MYB上游的WD40类因子和光敏色素的研究,开启了对从信号传导到花色素苷合成的整个调控过程的探索。

不同次生种源麻疯树对高温胁迫的响应

The response of two secondary provenances of Jatropha curcas originated respectively from Hainan Province and Guizhou Province to heat stress treatments was investigated.The capacity of scavenging organic free radical of DPPH· in both secondary provenances firstly increased and then decreased with increasing temperature,and presented one peak pattern.The peak value was at 30 ℃ in Guizhou secondary provenance and at 35 ℃ in Hainan secondary provenance,respectively.Antioxidative ability in Hainan secondary provenance was significantly higher than that in Guizhou secondary provenance under high temperature treatment(>35 ℃).The maximal photosynthetic evolution of oxygen was at 40 ℃ in Hainan secondary provenance,whereas 35 ℃ in Guizhou secondary provenance.There was little change in the maximal primary photochemical quantum efficiency(F_v/F_m)of the PSⅡ,however the non-circle PSⅡquantum efficiency(Φ_PSⅡ)and the photochemical quenching(q_P)of Hainan were obvious higher than those of Guizhou secondary provenance.The nonphotochemical quenching(NPQ)of Hainan displayed more tolerance to high temperature than that of Guizhou secondary provenance.F_o-temperature curves showed that the inflexion temperature(T_i)of Hainan and Guizhou secondary provenance was 52 ℃ and 50 ℃ respectively.The experiment results indicated that Hainan secondary provenance of J.curcas was able to maintain relative higher function of photosynthetic apparatus because of its high antioxidative ability and more stability of membrane under high temperature condition.This would be one of possible reasons that Hainan secondary provenance displayed stronger resistance to high temperature than Guizhou secondary provenance.

应用Tail-PCR扩增蓝猪耳T-DNA侧翼序列

蓝猪耳是一种重要的具有观赏和科研价值的花卉植物.采用TAIL-PCR成功扩增了转基因蓝猪耳T-DNA插入位点的侧翼序列,扩增片断长度为200～2000bp,大多数片段在400bp和800bp左右,其中36%的序列含有植物的同源序列.通过与GenBank数据库比对,确定了部分T-DNA插入位点周边序列编码的可能蛋白,并提交序列7条;另外还对T-DNA转化植物时整合的位点进行了分析,发现断裂位点集中在距右边界15～18bp和右边界外234bp处,分别占总扩增片段的47.62%和38.10%.这为利用T-DNA标签进行蓝猪耳基因克隆和功能分析提供了实验技术上的保证.

蓝光诱导的胶孢炭疽菌(Colletotrichum gloeosporioides)类胡萝卜素积累

胶孢炭疽菌(Colletotrichumgloeosporioides)为一种丝状真菌,蓝光照射可诱导类胡萝卜素的积累。光镜下观察表明,蓝光可诱导胶孢炭疽菌菌丝积累色素颗粒,而黑暗和红光处理却无此现象。类胡萝卜素的积累受蓝光光照强度的影响。28℃且蓝光为6.5μmol.m-2.s-1时,类胡萝卜素积累量可随光照时间延长呈增长趋势,在第5天达到最高峰为71.8μg/g FW,随后含量下降。此外,胶孢炭疽菌在黑暗中预培养的时间也影响蓝光的诱导反应。

花生愈伤组织的诱导及植株再生

研究花生愈伤组织的诱导及植株再生的条件．用汕油71花生幼苗上胚轴、下胚轴、子 叶、幼叶等不同外植体类型进行比较,发现幼叶较易诱导愈伤;用不同激素质量浓度配比研究对花 生幼叶愈伤诱导的影响,发现IAA(吲哚乙酸)对花生的愈伤诱导效果较2,4-D(2,4-二氯苯氧乙 酸)和NAA(萘乙酸)好;用不同叶龄及叶切段比较,发现以10 d苗龄的叶片中部切段愈伤诱导率较 高．取苗龄10 d的花生无菌苗的幼叶中段为外植体,置于ρ(MS+IAA)3 mg／L+ρ(BA)1 mg／L培养 基中培养,30 d后诱导率达到100％且愈伤呈淡绿色、半透明、疏松状．50 d后转至ρ(MS+IAA)0．5 mg/L+ρ(BA)2 mg／L+ρ(TDZ)0．5 mg/L分化培养基中诱导芽(TDZ,噻重氮苯基脲),截取诱导芽单 芽,转接至根诱导培养基中,获得再生植株．

紫花月季组织培养与快速繁殖研究

[目的]建立适宜的紫花月季[Rosa chinensis Jacq.var.semperflorens(Curtis)Koehne]无性繁殖体系。[方法]以紫花月季茎为外植体,对适合月季丛生芽诱导的培养基和切取外植体的方式进行优化筛选。[结果]芽诱导的最适培养基为MS+1.0mg/L6-BA+0.2mg/L GA3;丛生芽增殖的适宜培养基为MS+3.0mg/L6-BA+0.1mg/L NAA;再生芽在MS+0.5mg/L NAA培养基中生根效果最好。1个侧芽在经历21d丛生芽诱导和28d芽增殖培养后,可获得90多个再生芽。[结论]该研究可为实现紫花月季育苗的规模化和产业化生产提供参考。

转拟南芥AtNHX5基因烟草的耐盐性研究

采用农杆菌介导的叶盘法将来源于拟南芥的Na+/H+逆向转运蛋白基因AtNHX5导入烟草,经潮霉素筛选、PCR和RT-PCR检测,证明AtNHX5已导入烟草基因组并在转基因植株中表达。将转基因植株和非转基因(野生型)植株培养在含有300 mM NaCl的1/2MS培养基上,发现转基因植株的生长明显优于野生型。将在含有300 mM NaCl的1/2MS培养基中生长4周后的幼苗转移到不含NaCl的1/2MS培养基后,转基因植株快速恢复生长,而野生型植株则生长停滞。结果表明:超表达AtNHX5基因可以提高烟草的耐盐性。