施肥对烟草腺毛叶绿体形态结构的影响

以烤烟K326为材料,在盆栽条件下分别施用纯有机肥和无机肥,在烟株旺长期和成熟期对叶面腺毛进行显微和超微结构观察,以明确肥料对烟草叶面腺毛生长发育的影响,结果显示:移栽后50 d,荧光下观察有机肥处理下腺头细胞叶绿素荧光强度较无机肥强烈,腺头细胞内叶绿体结构完整,类囊体基粒片层发达,嗜锇颗粒大而多;无机肥处理的细胞内叶绿体少,嗜锇颗粒较小,数量也较少.移栽后70 d,有机肥处理腺毛头细胞叶绿体双层膜结构依然完整,但类囊体基粒片层结构已经解体,其中积累大量黑色嗜锇颗粒;此时无机肥处理腺毛头细胞叶绿体结构完整,仍可清晰看到类囊体基粒片层仅含少量嗜锇颗粒.推测有机肥处理在初期促进了烟草腺毛细胞叶绿体的发育和叶绿素的合成、积累,在后期,促进叶绿素及内膜系统的降解,并有利于亲脂类物质的合成和积累,从而对腺毛分泌物积累和烟叶香气品质形成具有积极影响.     

野薄荷叶腺毛的发育形态学研究

研究了分布于我国东北部的野薄荷叶表面腺毛的结构和发育。主要腺毛有两种：多细胞盾状腺毛和弯曲单细胞头状腺毛。多细胞盾状腺毛由１个基细胞,１个柄细胞和一个由８－１２个分泌细胞构成的头部组成。单细胞头状腺毛由１个基细胞,１个柄细胞和一个分泌细胞头部构成。     

细叶益母草叶表面腺毛多样性及发育形态学研究

本文研究了分布在细叶益母草(Leonurus sibiricus)叶表面三种腺毛的发育过程,在此基础上,对2-细胞头状腺毛、4-细胞头状腺毛和8-细胞盾状腺毛的多样性特征进行了讨论。     

不同生态区烟草的叶面腺毛基因表达

利用cDNA芯片技术,对同一烟草品种（Nicotina tabacum L cv. K326）、不同生态区(典型的浓香型烟区-河南平顶山和典型的清香型烟区-云南玉溪)、同一叶位(中部叶)、相同叶龄（60天）的叶片腺毛基因表达谱进行了比较研究,共发现有效差异表达基因445个。其中,与光合色素代谢、光合作用以及类萜生物合成相关基因在河南烟叶腺毛中高表达,与碳水化合物、蛋白质分解代谢过程相关的基因在云南烟叶腺毛中高表达;防御过程相关基因在两生态区均有高表达。该结果表明, 烟草叶面腺毛的基因表达水平受到生态因素的调控,生态因素有可能通过影响腺毛的物质代谢和分泌,从而对烟叶风格形成产生一定的影响。     

类根瘤对烟草叶片中叶绿体及其淀粉粒含量的影响

目的：探讨类根瘤对烟草叶片中的叶绿体及其淀粉粒含量的影响。方法：无菌培养烟草再生植株,其中一部分经过一定浓度的2,4－D与豇豆根瘤菌512快生型突变株菌液诱导处理,另外一部分为对照。运用常规电镜技术制作叶片厚切片,通过显微观察,对两组烟草叶片细胞中的叶绿体及其淀粉粒含量进行对比分析。结果：结瘤植株叶片细胞内的叶绿体含量虽然与对照之间无明显差异,但叶片栅栏组织和海绵组织细胞内淀粉粒的含量却均较对照减少,其中前者减少更为明显（P＜0.05)。结论：结瘤烟草叶片内光合产物的大量同化可能与类根瘤的形成有关。     

荇菜腺毛的发育及其分泌过程的超微结构研究

荇菜 (Nymphoides peltatum (Gmel.) O.Kuntz)腺毛由具分泌功能的单列圆筒状细胞组成。它们起源于苗端倒数第二叶原基近轴面 ,由原表皮细胞发育而来。处于分泌期的腺毛细胞其胞质浓厚 ,液泡化程度小。细胞内具丰富的线粒体、高尔基体和内质网等细胞器 ,还具发达的胞间连丝。粘液物质由高尔基体分泌小泡、内质网分泌小泡及多膜体共同携带至细胞边缘 ,经胞吐和渗透相结合的方式分泌至细胞外。腺毛细胞侧壁因积有大量分泌物而呈膨胀状态。经检测 ,粘液由多糖和蛋白质组成 ,对营养芽的生长发育起保护作用。     

细叶益母草(Leonurus sibiricus)叶表面腺毛多样性及发育形态学研究

本文研究了分布在细叶益母草（Ｌｅｏｎｕｒｕｓｓｉｂｉｒｉｃｕｓ） 叶表面三种腺毛的发育过程,在此基础上,对２细胞头状腺毛、４细胞头状腺毛和８细胞盾状腺毛的多样性特征进行了讨论     

冬凌草腺毛的形态学及组织化学研究

利用光学显微镜对药用植物冬凌草地上部分腺毛的形态、分布和组织化学进行了研究。结果表明:(1)冬凌草的叶表皮有3种形态显著不同的毛,即非腺毛、盾状腺毛和头状腺毛;盾状腺毛和头状腺毛均具1个基细胞、1个柄细胞和头部;成熟的盾状腺毛的头部一般由4个分泌细胞组成,而头状腺毛头部由2个分泌细胞组成。(2)组织化学鉴定结果显示:2种腺毛中均含有黄酮类成分,盾状腺毛中还含有单萜、倍半萜等萜类成分;冬凌草甲素可能只存在于盾状腺毛中,但需要更直接的证据证明。研究认为,高密度的盾状腺毛可以作为筛选冬凌草高甲素含量品种的一项重要依据。     

龙葵腺毛发育的细胞学研究

利用光学显微镜、扫描电镜和透射电镜技术,观察了龙葵“四叶一心”期时叶片及茎表皮的腺毛的种类、分布,探究了不同类型腺毛的起源、生长、成熟、分泌、衰老等发育过程的细胞学特征;通过组织化学染色和荧光显微技术,观察了龙葵腺毛成分、分布,为龙葵的进一步开发利用提供参考。结果表明：（1）龙葵腺毛分为单细胞头腺毛和多细胞头腺毛两类,前者主要分布于茎表面和叶上下表皮,后者主要分布于茎表面的单细胞头腺毛之间、叶脉及叶边缘;（2）龙葵腺毛发育起始于表皮细胞突起,单细胞头腺毛行顶端生长,具1-4个柄细胞,四种类型;多细胞头腺毛可再分为一层、两层与三层多细胞头腺毛,另具三种特殊类型;（3）龙葵成熟腺毛具分泌能力,通过皮下空间的物质积累导致腺毛头细胞表面形成突起、包块、破口,最终释放分泌物;而头细胞与柄细胞随即皱缩、衰老。（4）超微结构显示,腺毛头细胞中内质网与高尔基体极为丰富,合成代谢及分泌活动活跃,产生大量包裹嗜锇物质的囊泡,囊泡与细胞壁融合,进而将嗜锇物质转移至细胞壁并积累,随后储存在角质层下的皮下空间直至分泌释放;（5）组织化学染色结果表明,腺毛含有萜类、生物碱、脂类、蛋白质、酚类和多糖。头细胞中主要含有萜类、生物碱、脂类、蛋白质、酚类和中性多糖;柄细胞中主要含有萜类、生物碱、脂类。     

NADK2, an <Emphasis Type="Italic">Arabidopsis</Emphasis> Chloroplastic NAD Kinase,Plays a Vital Role in Both Chlorophyll Synthesis and Chloroplast Protection

As one of terminal electron acceptors in photosynthetic electron transport chain, NADP receives electron and H⁺ to synthesize NADPH, an important reducing energy in chlorophyll synthesis and Calvin cycle. NAD kinase (NADK), the catalyzing enzyme for the de novo synthesis of NADP from substrates NAD and ATP, may play an important role in the synthesis of NADPH. NADK activity has been observed in different sub-cellular fractions of mitochondria, chloroplast, and cytoplasm. Recently, two distinct NADK isoforms (NADK1 and NADK2) have been identified in Arabidopsis. However, the physiological roles of NADKs remain unclear. In present study, we investigated the physiological role of Arabidiposis NADK2. Sub-cellular localization of the NADK2–GFP fusion protein indicated that the NADK2 protein was localized in the chloroplast. The NADK2 knock out mutant (nadk2) showed obvious growth inhibition and smaller rosette leaves with a pale yellow color. Parallel to the reduced chlorophyll content, the expression levels of two POR genes, encoding key enzymes in chlorophyll synthesis, were down regulated in the nadk2 plants. The nadk2 plants also displayed hypersensitivity to environmental stresses provoking oxidative stress, such as UVB, drought, heat shock and salinity. These results suggest that NADK2 may be a chloroplast NAD kinase and play a vital role in chlorophyll synthesis and chloroplast protection against oxidative damage.     

植物叶绿素缺失突变体分子机制研究进展

植物叶绿素缺失突变体在自然界中广泛存在,是研究叶绿素形成和叶绿体发育等代谢途径的良好材料.该文主要从分子层面上阐述了叶绿素缺失突变体产生的原因,如叶绿素合成受阻、叶绿体光合蛋白合成或输入受阻、叶绿体RNA转录物未被编辑、过量光损伤和卟啉循环各物质之间的相互抑制,并归纳了近年来鉴定出来的一些叶绿素缺失突变基因,简要介绍了叶绿素和叶绿体之间的关系以及叶绿素缺失突变体的应用.     

Observation and characterisation of a transient in the yield of chlorophyll fluorescence in intact spinach chloroplasts

A transient in chlorophyll fluorescence, which is associated with a transient in 9-aminoacridine fluorescence and a perturbation in the rate of oxygen evolution, has been observed in intact spinach chloroplasts. The results indicate that changes in the redox state of Q are, at least partially, responsible for the transient in chlorophyll fluorescence. The size of the transient is highly dependent upon the concentration of inorganic phosphate and upon the pH of the medium. The properties of the transient are consistent with the suggestion that it reflects changes in the levels of stromal intermediates during induction.Abbreviations BES NN-Bis(2-hydroxyethyl)2-aminoethanesulphonic acid dihydroxyacetone-P(DHAP): dihydroxyacetone phosphate glycerate-3-P (PGA): glycerate-3-phosphate - HEPES N-2-Hydroxyethylpiperazine-N-2-ethanesulphonic acid - MES 2-(N-Morpholino)ethanesulphonic acid - Pi inorganic phosphate - qE quenching of chlorophyll fluorescence by the energisation of the thylakoid membrane - qQ quenching of chlorophyll fluorescence by oxidised Q, the electron acceptor of photosystem 2 - ribose-5-P (R5P) ribose-5-phosphate - Rbu-5-P ribulose-5-phosphate     

Phosphorescence of protochlorophyll(ide) and chlorophyll(ide) in etiolated and greening bean leaves

The assignment is presented for the principal phosphorescence bands of protochlorophyll(ide), chlorophyllide and chlorophyll in etiolated and greening bean leaves measured at -196°C using a mechanical phosphoroscope. Protochlorophyll(ide) phosophorescence spectra in etiolated leaves consist of three bands with maxima at 870, 920 and 970 nm. Excitation spectra show that the 870 nm band belongs to the short wavelength protochlorophyll(ide), P627. The latter two bands correspond to the protochlorophyll(ide) forms, P637 and P650. The overall quantum yield for P650 phosphorescence in etiolated leaves is near to that in solutions of monomeric protochlorophyll, indicating a rather high efficiency of the protochlorophyll(ide) triplet state formation in frozen plant material. Short-term (2–20 min) illumination of etiolated leaves at the temperature range from -30 to 20°C leads to the appearance of new phosphorescence bands at about 990–1000 and 940 nm. Judging from excitation and emission spectra, the former band belongs to aggregated chlorophyllide, the latter one, to monomeric chlorophyll or chlorophyllide. This indicates that both monomeric and aggregated pigments are formed at this stage of leaf greening. After preillumination for 1 h at room temperature, chlorophyll phosphorescence predominates. The spectral maximum of this phosphorescence is at 955–960 nm, the lifetime is about 2 ms, and the maximum of the excitation spectrum lies at 668 nm. Further greening leads to a sharp drop of the chlorophyll phosphorescence intensity and to a shift of the phosphorescence maximum to 980 nm, while the phosphorescence lifetime and a maximum of the phosphorescence excitation spectrum remains unaltered. The data suggest that chlorophyll phosphorescence belongs to the short wavelength, newly synthesized chlorophyll, not bound to chloroplast carotenoids. Thus, the phosphorescence measurement can be efficiently used to study newly formed chlorophyll and its precursors in etiolated and greening leaves and to address various problems arising in the analysis of chlorophyll biosynthesis.Abbreviations Pchl protochlorophyll and protochlorophyllide - Chld chlorophyllide - Chl chlorophyll     

POR C of Arabidopsis thaliana: a third light- and NADPH-dependent protochlorophyllide oxidoreductase that is differentially regulated by light

During the sequencing of the genome of Arabidopsis thaliana a gene has been identified that encodes a novel NADPH-protochlorophyllide oxidoreductase (POR)-like protein (accession number AC 002560). This protein has been named POR C. We have expressed the POR C protein in Escherichia coli and have determined its in vitro activity. POR C shows the characteristics of a light-dependent and NADPH-requiring POR similar to POR A and POR B. The expression of the POR C gene differs markedly from that of the POR A and POR B genes. In contrast to the POR A and POR B mRNAs, the POR C mRNA has been shown previously to accumulate only after the beginning of illumination. In light-adapted mature plants only POR B and POR C mRNAs were detectable. The amounts of both mRNAs show pronounced diurnal rhythmic fluctuations. While the oscillations of POR B mRNA are under the control of the circadian clock, those of POR C mRNA are not. Another difference between POR B and POR C was found in seedlings that were grown under continuous white light. The concentration of POR C mRNA rapidly declined and soon dropped beyond the limit of detection, after these seedlings were transferred to the dark. On the other hand, POR B mRNA was unaffected by this light/dark shift. When seedlings were exposed to different light intensities, the amounts of POR B mRNA remained the same, while POR A and POR C mRNAs were modulated in an inverse way by these light intensity changes. POR A mRNA was still detectable in seedlings grown under low light intensities but disappeared at higher light intensities, while the mRNA concentration of POR C rose with increasing light intensities. These different responses to light suggest that the functions of the three PORs of Arabidopsis are not completely redundant, but may allow the plant to adapt its needs for chlorophyll biosynthesis more selectively by using preferentially one of the three enzymes under a given light regime.     

硫对成熟期烤烟叶绿素荧光参数的影响

通通过液培试验,研究了硫浓度(0.01-32 mmol/L)对成熟期烤烟叶片叶绿素含量和叶绿素荧光参数的影响。结果表明,成熟期烤烟叶绿素a和叶绿素b含量随硫浓度的升高而逐渐增加,但各处理差异未达到显著水平。在2-32 mmol/L处理之间,烤烟叶片的有效量子产量（EQY）、最大量子产量（Fv/Fm）、光合电子传递速率（ETR）随硫浓度增加而降低,非光化学猝灭（NPQ）、非光化学过程中的基本量子产量（Fo/Fm）、PSⅡ水裂解端失活程度（Fo/Fv）和PSⅡ反应中心关闭程度（1-qP）随硫浓度增加而升高,2 mmol/L处理的质体醌库（Fv/2）低于4 mmol/L处理外,但其它处理的均随硫浓度升高而降低。0.01 mmol/L处理烤烟叶片的EQY、Fv/Fm和ETR低于2-8 mmol/L处理,但高于16 mmol/L和32 mmol/L处理,其NPQ、Fo/Fm、Fo/Fv和1-qP变化趋势则与之相反;0.01 mmol/L处理的Fv/2低于4 mmol/L处理的,但高于2 mmol/L及8-32 mmol/L处理;低硫处理烤烟EQY、Fv/Fm和ETR的降低可能不是由Fv/2引起的,而是由于1-qP升高引起的。但16 mmol/L和32 mmol/L处理Fv/Fm 、ETR、EQY降低可能是1-qP与 Fv/2共同作用的结果。