植物生理学双语教学的实践与创新

对近几年来植物生理学课程双语教学内容、教学方法、教学手段及考核方式等方面的改革进行了较深入的探讨与实践。通过研制双语教学网络课件,选择正确的国外原版教材和国内教材、编写合适的双语教学讲义,采用形式多样的双语教学模式,正确处理专业词汇和建立有效的考核机制等途径来提高双语教学质量,实现教学目标。     

某些酸类物质对水稻开颖的效应

将稻穗置不同种类、浓度的酸溶液中浸泡后,观察其对颖花开放及颖花活性的影响,发现0．5％～10％的甲酸、乙酸和丙酸均能显著地诱导水稻开颖。当甲酸浓度在0．5％－1．5％、乙酸和丙酸浓度在0．5％－2％的范围内对颖花无不良影响。硝酸、盐酸和硫酸等在一定的浓度下能诱导开颖,但同时又对颖花产生伤害。另外,水杨酸、苹果酸等在适宜的浓度下也能诱导水稻开颖。酸可以促使浆片细胞壁的松弛,加快浆片吸水膨胀。酸诱导开颖的时间约为30s,作用部位为浆片;酸的诱导效应可被呼吸抑制剂NaN3所抑制。     

植物向光性反应的研究进展

本文对近年来有关植物向光性反应的研究结果作一综述:1)向光素和隐花色素是植物向光反应中的主要光受体,光敏色素在植物向光性反应中也起一定的作用;2)对植物的光辐照度-弯曲度曲线的分析,可知植物的正向光性运动有两种反应,即第一次正向光性弯曲和第二次正向光性弯曲;3)拟南芥(Arabidopsisthaliana)和水稻(Oryza sativa)等植物的根系具有负向光性的特性,根的负向光性倾斜生长角度为负向光性生长和向重性生长相互作用的矢量和;4)生长素的胞间运输依赖于生长素载体,生长素载体的不对称分布和动态运动是生长素极性运输和向性运动的分子基础.     

介绍拍摄几种植物运动的方法

介绍用显微摄影装置定格拍摄气孔开闭、颖花开闭、浆片膨大、花粉萌发,用扫描仪录入稻穗开花以及用相机拍摄稻根负向光性生长等植物运动的技术和方法,并展示所摄植物运动的照片。     

转反义Wx基因水稻颖果中与淀粉合成和积累相关酶活性的变化

将反义Wx基因转入水稻,导致Wx蛋白不同程度减少,颖果中的直链淀粉含量不同程度下降,总淀粉含量显著降低,直链淀粉与总淀粉的比值极显著降低。在水稻颖果发育过程中,ADPG-PPase、GBSS、SSS和SBE的活性在灌浆前期迅速升高,达最大值后很快下降,在灌浆中后期下降趋缓。Wx蛋白减少后的转基因水稻颖果中的GBSS活性明显下降,下降幅度与直链淀粉含量相一致,而且活性高峰期比其亲本有所提前。转基因水稻颖果中ADPG-PPase和SSS的活性在颖果发育的前中期,SBE则在中后期高于相应的亲本。     

环境因素对水稻颖花开闭影响的机理

水稻颖花的开闭受多种因素的影响。３５－４０℃的温度,含＞５％ＣＯ２的气体和饱和ＣＯ２和水溶液能显著促进开颖;低温、呼吸抑制剂抑制颖开闭。温度对颖开闭过程没有影响,开颖前数日的浆片细胞中含有淀粉,开颖时淀粉粒已消失,开颖后,浆片细胞开始自溶,细胞的解体物通过导管向小穗轴撤离,根椐对温度和呼吸抑制剂的反应,可把水稻颖开闭过程分为三个阶段：１．与呼吸有关的临开颖阶段,２．与呼吸无关的开颖阶段,３．与呼吸     

Negative phototropism of rice root and its influencing factors

Some characteristics of the rice (Oryza sativa L.) root were found in the experiment of unilaterally irradiating the roots which were planted in water: (i) All the seminal roots, adventitious roots and their branched roots bent away from light, and their curvatures ranged from 25℃ to 60℃. The curvature of adventitious root of the higher node was often larger than that of the lower node, and even larger than that of the seminal root. (ii) The negative phototropic bending of the rice root was mainly due to the larger growth increment of root-tip cells of the irradiated side compared with that of the shaded side, (iii) Root cap was the site of light perception. If root cap was shaded while the root was irradiated the root showed no negative phototropism, and the root lost the characteristic of negative phototropism when root cap was divested. Rice root could resume the characteristic of negative phototropism when the new root cap grew up, if the original cells of root cap were well protected while root ca     

植物叶片中Rubisco含量的免疫沉淀法测定

Rubisco为光合生物中的关键性酶,对光合作用起重要的调节作用,Rubisco又是植物中重要的氮源贮藏物质。因而Ｒu-bisco的定量测定十分重要,以扬麦为实验材料,提取,纯化Ｒubisco,再以纯化的Ｒubisco为抗原制备Ｒubisco抗体,利用所得抗体采用免疫沉淀技术测定不同植物中的Ｒubisco含量,为Ｒubisco的准确定量测定提供了较简便,快速的方法。     

Negative phototropism of rice root and its influencing factors

Some characteristics of the rice (Oryza sativa L.) root were found in the experiment of unilaterally irradiating the roots which were planted in water: (i) All the seminal roots, adventitious roots and their branched roots bent away from light, and their curvatures ranged from 25° to 60°. The curvature of adventitious root of the higher node was often larger than that of the lower node, and even larger than that of the seminal root, (ii) The negative phototropic bending of the rice root was mainly due to the larger growth increment of root-tip cells of the irradiated side compared with that of the shaded side, (iii) Root cap was the site of light perception. If root cap was shaded while the root was irradiated the root showed no negative phototropism, and the root lost the characteristic of negative phototropism when root cap was divested. Rice root could resume the characteristic of negative phototropism when the new root cap grew up, if the original cells of root cap were well protected while root cap was divested, (iv) The growth increment and curvature of rice root were both influenced by light intensity. Within the range of 0–100 μmol · m² -s⁻¹, the increasing of light intensity resulted in the decreasing of the growth increment and the increasing of the curvature of rice root, (v) The growth increment and the curvature reached the maximum at 30°C with the temperature treatment of 10–40°C. (vi) Blue-violet light could prominently induce the negative phototropism of rice root, while red light had no such effect. (vii) The auxin (IAA) in the solution, as a very prominent influencing factor, inhibited the growth, the negative phototropism and the gravitropism of rice root when the concentration of IAA increased. The response of negative phototropism of rice root disappeared when the concentration of IAA was above 10 mg · L⁻¹     

CO_2促进水稻开花的效应

水稻开花前,颖花的呼吸强度增高,颖内CO_2浓度上升至5％左右。若用5％以上的CO_2气体或低pH值的CO_2水溶液处理稻穗0.5—2分钟,当天和第二天开花的小穗在5—10分钟后开颖,并为温度增高所促进,呼吸抑制剂不能中断已被CO_2诱导的开颖过程。CO_2诱导开颖是鳞片吸水增强后膨大所致。