Both wound-inducible and tuber-specific expression are mediated by the promoter of a single member of the potato proteinase inhibitor II gene family

A chimeric gene consisting of 1.3 kb of the 5' regulatory region of a member of the potato proteinase inhibitor II gene family, the coding region of the bacterial β-glucuronidase (GUS) gene and 260 bp of the proteinase inhibitor II 3'-untranslated region containing the poly(A) addition site was introduced into potato and tobacco by Agrobacterium tumefaciens mediated transformation. Analysis of transgenic plants demonstrates systemic, wound-inducible expression of this gene in stem and leaves of potato and tobacco. Constitutive expression was found in stolons and tubers of non-wounded potato plants. Histochemical experiments based on the enzymatic activity of the GUS protein indicate an association of the proteinase inhibitor II promoter activity with vascular tissue in wounded as well as in systemically induced non-wounded leaves, petioles, potato stems and in developing tubers. These data prove that one single member of the proteinase inhibitor II gene family contains cis-active elements, which are able to respond to both developmental and environmental signals. Furthermore they support the hypothesis of an inducing signal (previously called proteinase inhibitor inducing factor), which is released at the wound site and subsequently transported to non-wounded parts of the plant via the vascular system from where it is released to the surrounding tissue.     

Both developmental and metabolic signals activate the promoter of a class I patatin gene

Patatin is one of the major soluble proteins in potato tubers and is encoded by a multigene family. Based on structural considerations two classes of patatin genes are distinguished. The 5′-upstream regulatory region of a class I gene contained within a 1.5 kb sequence is essential and sufficient to direct a high level of tuber-specific gene activity which was on average 100- to 1000-fold higher in tubers as compared to leaf, stem and roots in greenhouse grown transgenic potato plants when fused to the β-glucuronidase reporter gene. Histochemical analysis revealed this activity to be present in parenchymatic tissue but not in the peripheral phellem cells of transgenic tubers. Furthermore the promoter fragment can be activated in leaves under conditions that simulate the need for the accumulation of starch in storage organs, i.e. high levels of sucrose. The expression is restricted to both mesophyll and epidermal cells in contrast to vascular tissue or hair cells.     

《生物化学》课播讲前致学员的公开信

同学们好! 中国电视师范学院生物专业生物化学课将于今年9月1日播讲。为了有利于大家学好这门课,在开播前讲几点意见,供大家参考。本课使用的教材是钟洪枢、关基石主编的《生物化学》一书。计划讲授60学时。鉴于大家已经学过有机化学,所以第一章“糖类化学”、第二章“脂类化学”就不在课上介绍了。讲授中,对教科书的内容将会做某些增删,希望同学们在课后认真阅读教材。《生物化学》是一门实验性科学,生物化学实验是生物化学课的重要内容。由于条件所限,同学们不一定都有机会学习生化实验,故在课堂讲授中所安排的演示实验,希望大家能在听讲的同时,注意观察实验现象和学习了解有关实验技术,以便加深对课程内     

涡虫双头双尾的再生实验

实验步骤 1.将活涡虫移入到培养皿中,并加少量清洁的培养液。 2.用锋利的手术刀(也可用刮脸双面刀片代替)在解剖镜下(若无解剖镜也可用肉眼)对涡虫进行切割。将切下的残片移入到其他培养皿中(一个培养皿中只放一个残片)。 3.在培养皿中加入足量的培养液,加盖防止水分蒸发干。 4.将培养皿放于15℃左右的阴暗处保存,每隔2     

“叶”的一章教学应注意的问题

植物在生活过程中所需的有机养料,都是通过光合作用制造的,这是绿叶的主要生理功能。此外,叶还具有进行呼吸作用和蒸腾作用的生理功能。研究绿叶的生理功能是本章教学的中心问题,完成好本章的教学任务,我们认为应注意以下几个问题:     

九月份生物各学科实验准备

植物学(实验一和实验二) 材料用具:显微镜(低倍镜)、小块紫色洋葱鳞茎(若无紫色洋葱时,还需准备碘液染色)、内盛清水的小烧杯、吸管、镊子、刀片、牙签(代替解剖针)、载玻片、盖玻片、小片吸水纸、绘图纸,番茄、红色柿子椒各一个(演示用)。示范镜的准备:1.示成熟的番茄果肉细胞:用牙签挑取果肉细胞制成装片观察。2.示辣椒表皮细胞:将柿子椒用小刀切成小块,清除掉果肉制成无色表皮细胞,观察胞间连丝,如用卡宝染液(改良苯酚品红染色液)染色效果更好。卡宝染色液配制方法如下: ①取3克碱性品红,溶于100m170％酒精中,配成母液     

我们怎样开展对青少年的青春期教育

对中学生进行青春期教育是学校进行系列化教育的重要一环,是学校、家庭和社会的共同任务,也是关系到国家民族的未来,使青少年健康成长的重要问题。因此,有必要正确引导中学生了解生理和心理上的变化,克服消极因素,以便使他们集中精力,学好知识本领,     

大麦花粉发育的电镜观察(封二照片说明)

本文用透射电镜观察了大麦(品种苏啤一号)花药中花粉母细胞发育成花粉粒的过程。图1 花粉母细胞时期花药横切面局部,×2350。花药可分为两个部分:花药壁层和花粉母细胞。花药壁层由四层细胞组成,自外向内为表皮