Insertion Profiles in Stomatal Density and Sizes in Nicotiana Tabacum L. Plantlets

Tobacco (Nicotiana tabacum L. cv. Samsun) plantlets were cultured in vitro on Murashige-Skoog medium photoautotrophically (without sucrose) or photomixotrophically (with 3 % sucrose) under two irradiances [70 or 230 µmol m^–2 s^–1]. Significant differences in stomatal density and sizes in leaves of different insertion levels (3^rd, 5^th and 7^th leaves from bottom) in photomixotrophic plantlets but not in photoautotrophic ones were found after 35 d of culture. Stomatal density was higher in upper leaves and on abaxial leaf side. Higher irradiance enhanced stomatal density in photoautotrophic plantlets. Stomatal sizes decreased with leaf insertion level but no significant differences between leaf sides were found. Abaxial stomata were more circular than the adaxial ones. In photomixotrophic plantlets stomata tended to be more elongated in the 3^rd and the 5^th leaves, whereas stomatal elongation in photoautotrophic plantlets was similar in all leaves.     

普通烟草ARF基因家族序列的鉴定与表达分析

ARF(AUXIN RESPONSE FACTOR)基因含有一个B3功能域和具有转录激活或抑制活性的中心功能域,在植物发育过程中起到非常重要的作用。本研究采用生物信息学方法,根据拟南芥ARF基因序列鉴定了普通烟草基因组中的ARF基因,并对家族成员进行了序列特征、系统发生、亚细胞定位和表达模式分析。目前在普通烟草基因组中共得到50个ARF基因成员,其基因结构相对复杂,一般含有10个外显子。亚细胞定位结果表明,少数ARF蛋白定位到线粒体或叶绿体,大多数未检测到定位信号。转录组数据分析表明,ARF基因具有不同的组织表达模式,部分基因表现出组织特异性。这些研究结果为普通烟草ARF基因家族功能的深入研究奠定了基础。     

Multi-Phasic Kinetics of P700+ Dark Re-Reduction in Nicotiana Tabacum

Reduction kinetics of P700⁺ after far-red radiation (FR)-induced oxidation in intact tobacco leaves was examined by analysing the post-irradiation relaxation of 810–830 nm absorbance difference. The reduction curve could be de-convoluted distinctively into two or three exponential decaying components, depending on the FR irradiance, the treating and measuring temperatures, and the extent of dark adaptation. The multi-phasic kinetics of P700⁺ re-reduction upon the turning off of FR irradiation is related to the heterogeneity of electron transport around photosystem 1 in thylakoid membranes.     

Anomalie In Plante Di Nicotiana Tabacum L. Derivate Da Semi Trattati Con Neutroni Termici

Abstract

The endemic species in the peninsula of Capo Caccia (N. W. Sardinia). — The author signals the presence of some endemic species in the Peninsula of Capo Caccia (N. W. Sardinia)     

烟草渗调蛋白基因的分离克隆及序列分析

参照国外报道的渗调蛋白基因序列,自行设计并合成了一对寡核苷酸引物,通过ＰＣＲ技术从云南地方栽培的烤烟品种“红花大金元”基因组ＤＮＡ中直接扩增出了其全编码序列。ＰＣＲ产物纯化后直接克隆到ｐＧＥＭ－Ｔ载体系统中,转化大肠杆菌ＤＨ５α,在Ｘｇａｌ平板上筛选白色菌落,经ＳｐｈＩ和ＳａｃＩ双酶切,鉴定所得的重组质粒中含有７５３ｂｐ左右的ＰＣＲ扩增片段。采用双链双脱氧法定序分析表明所克隆的渗调蛋白基因编码区序列与国外迄今所报道的两个株系的序列完全一致,提示了该基因在进化上的保守性