The differences between two tea varieties in their response to natural cold conditions

In this study, two tea varieties (Camellia sinensis cv. CsCr02 and CsCr03) were studied under natural cold conditions to investigate the differences of thylakoid membrane structure, fatty acid desaturase (FAD) genes, and fatty acid (FA) composition in response to low temperatures. Quantitative real-time polymerase chain reaction assay confirmed that the expression of CsFAD8 in leaves of the two tea varieties was much higher than that of CsFAD7. The expression of both genes in CsCr03 was higher than in CsCr02. Electron microscopy showed that the damage to the thylakoid membrane in CsCr03 was less severe than in CsCr02 during the decrease of natural temperature. Changes in thylakoid membrane integrity coincided with the gradual decline in chlorophyll concentration and chlorosis of the tea leaves. With the decrease of natural temperature, a decline in the trienoic FA species (16:3 and 18:3) and an increase in the dienoic species (18:2) were observed in the two varieties. These results indicate that CsCr03 has higher cold adaptability compared to CsCr02.     

棉花芽黄突变体10个叶绿体蛋白编码基因RNA编辑位点的测定及分析

 RNA编辑是陆生植物叶绿体转录后基因表达调控的一种方式。已有研究表明植物黄化或白化可能与叶绿体RNA编辑有关。本实验采用PCR,RT-PCR及测序的方法,确定棉花芽黄突变体V1子叶与真叶的10个叶绿体蛋白编码基因中各有34个编辑位点,有6个位点存在编辑效率的差异。将这些编辑位点与柯字310比较发现,芽黄突变体多5个编辑位点。运用生物信息学软件对34个编辑位点进行分析,结果表明accD-109, clpP-187, ndhB-50, ndhB-196, ndhD-128, ndhD-225等13个位点会影响相应蛋白二级或三级结构,表明上述编辑位点的改变可能对其蛋白的正确组装及功能的发挥起重要作用。     

Effects of elevated atmospheric CO2 concentration on morphology of leaf blades in Chinese yam

ABSTRACT

The effects of elevated carbon dioxide concentration on the morphology of leaf blades in two Chinese yam lines under different temperature conditions were determined. Plants were grown under two [CO₂] levels, ambient (about 400 µmol mol^?1) and elevated (ambient + 200 µmol mol^?1) in the daytime, and two mean air temperature regimes, approximately ambient temperature (22.2°C) and high temperature (25.6°C). The palisade layer was thicker under elevated [CO₂] than under ambient [CO₂] in both temperature regimes, and the whole yam leaf blade was thicker under elevated [CO₂] than under ambient [CO₂] in the approximately ambient temperature regime. The numbers of chloroplasts per palisade cell and spongy cell as well as per unit profile area of palisade cell, number of starch grains per chloroplast, profile area of the starch grain, and starch-to-chloroplast area ratio in both palisade and spongy cells were higher under elevated [CO₂] than under ambient [CO₂] in both temperature regimes. Furthermore, the stomatal density on the abaxial side of the leaf blade in Chinese yam was greater under elevated [CO₂] than under ambient [CO₂] under both temperature regimes, and stomatal-pore length was higher under elevated [CO₂] than under ambient [CO₂] in the approximately ambient temperature regime. These results indicate that elevated [CO₂] positively affects the photosynthetic apparatus. The results of this study provide information for understanding the response characteristics of the leaf blade under elevated [CO₂] and a possible explanation for the positive photosynthetic responses of Chinese yam to elevated [CO₂] in our previous study.

List of Abbreviations:[CO₂]: carbon dioxide concentration     

Effects of Salinity Stress on the Structure of Bundle Sheath and Mesophyll Chloroplasts in NAD-Malic Enzyme and PCK Type C4 Plants

Abstract

The effect of NaCl stress on the structure of leaf chloroplasts was investigated in several NAD-Malic enzyme (NAD-ME) and phosphoenolpyruvate carboxykinase (PCK) type C₄ plant species. Seedlings of the monocot species, except Zoysia japonica, grown in 300 mL pots were subjected to salt stress by adding 50 mL of 3% NaCl solution per day to the soil for 5 d after the fourth leaf blades were fully developed. Z. japonica and the dicot species, Amaranthus tricolor, were also treated with 3% NaCl in a similar manner from 5 wk after germination. Salt stress negatively affected the growth, chlorophyll content and chloroplast structure in all the species. At the ultrastructure level, swelling of thylakoids and disruption of envelopes were more or less observed in mesophyll cell (MC) chloroplasts after salt treatment. The structure of bundle sheath cell (BSC) chloroplasts, on the other hand, was hardly damaged under salt condition although stromal and starch areas were considerably decreased. Furthermore, salinity induced granal development in BSC chloroplasts in most species; the number of thylakoids per granum, granal indices and appressed thylakoid density in salt-treated plants were generally higher than those in control. Since the similar responses have also been reported in all NADP-ME type C₄ species investigated in our previous study, the high sensitivity to salt stress in MC chloroplasts and the granal development in BSC chloroplasts by salinity were considered to be common phenomena in all three C₄ subtypes.     

外源硅缓解库拉索芦荟盐胁迫伤害效应的细胞生理学分析

为探索硅(Si)增强微咸水长期灌溉下库拉索芦荟(Aloe veraL.)耐盐性的机制,研究了盐(NaCl 100mmol.L-1)胁迫下加Si(2.0 mmol.L-1)处理30 d对库拉索芦荟叶同化组织细胞中矿质离子分布、叶绿体超微结构和腺苷三磷酸(ATP)酶活性的影响。X-射线能谱微域分析结果表明,盐胁迫下加Si,芦荟叶同化组织细胞中钠离子(Na )和氯离子(Cl-)相对含量显著下降,伴随着钾离子(K )相对含量显著升高、钾钠比(K /Na )显著增大。同时,加Si利于保持芦荟叶绿体正常形态,保护光合层片精细结构,显著缓解盐胁迫对其光合细胞器的伤害。利用电镜-细胞化学技术首次表明,提高浇灌溶液中可溶性Si含量水平,明显增强盐胁迫下芦荟叶同化组织细胞中胞间连丝、质膜和液泡膜ATP酶活性。外源Si增强盐胁迫下芦荟叶同化组织细胞中ATP酶活性是其改善叶同化组织细胞中的离子分布、缓解芦荟盐胁迫伤害效应的重要机制。     

桑树不同倍数体间形态学与组织学差异的比较研究(英文)

对 2倍体、3倍体和 4倍体桑树的形态学和组织学差异进行了研究 ,测定了不同倍数性桑树的单条长度、株条长度、单叶重、单叶面积和气孔的叶绿体数。结果表明 ,所有这些数量性状在不同倍数性间都存在统计学上的显著差异。单条长与株条长度为 3x >2x >4x,单叶重 ,叶面积和叶绿体数为 4x >3x >2x。此特征可以作为多倍体育种程序中初始阶段鉴别与筛选不同倍数体的辅助指标。研究还表明 ,3倍体有着优良的经济性状 ,由两种杂交组合培育的三倍体中 ,平均单条长 2x♀× 4x 显著长于 4x♀× 2x ;从 2倍体杂种实生苗诱导的 4倍体比 2倍体无性系诱导的 4倍体有更好的经济性状。     

油桐属与石栗属叶绿体的核酸、蛋白质及超微结构的初步研究

叶绿体超微结构是叶绿体形态和功能的重要内容之一。叶绿体除在光合作用中具有重要的功能外,在高等植物细胞质遗传中,作为细胞器也具有重要的作用。据估计,叶绿体DNA的信息量足以编码分子量为40000道尔顿的多肽约150—300个。不同种的叶绿体蛋白质存在差异。不同品种的叶绿体显微结构也存在明显差异。前文已发现油桐属和石栗属在叶片的核酸、蛋白质以及叶绿素含量上存在明显差异。本文试图对该两属的叶绿体超微结构及核酸和蛋白质含量进行比较研究,以提供进一步依据。     

有机肥和化肥对烟叶气体交换、叶绿素荧光特性及叶绿体超微结构的影响

【目的】本文以烤烟K326为材料,探讨了在不同叶龄时期有机肥与化肥在烟叶气体交换参数、叶绿素荧光特性、叶绿素含量及叶绿体超微结构等方面的差异,以期从光能利用(宏观)及叶绿体超微结构(微观)方面,揭示两种肥料配比对烟叶光合作用的影响机制,同时为探索烟叶高产优质栽培模式提供理论依据。【方法】以蛭石为栽培基质进行盆栽试验。设施用烤烟专用有机肥(N∶P2O5∶K2O为9∶9∶10,有机质≥70%,中、微量元素≥12%)和施用普通尿素两个处理。烟草为工厂化无毒育秧苗,叶龄(叶龄从叶片长约2 cm时算起)15天、30天、45天、60天和75天取样或测定自上而下第6~8片叶。用Li-6400(美国)便携式光合仪测定烟叶的净光合速率,蒸腾作用与气孔导度。使用M系列调制叶绿素荧光成像系统Maxi-Imaging-PAM(德国)测定叶绿素荧光参数。用C-7000透射电子显微镜观测叶绿体超微结构并拍照,用软件Auto CAD 2004计算淀粉颗粒在叶绿体中所占的相对面积比Ra,叶绿体基粒片层的统计方法据Goodenough等改进的Teichler-Zallen法。【结果】有机肥对烟叶叶绿素含量及光合速率的影响显著,在叶龄60天时,其叶绿素含量比普通化肥高136.1%;在叶龄75天时,其烟叶净光合速率、气孔导度及蒸腾速率分别比普通化肥处理高135.3%、84.5%和51.3%,叶绿素荧光参数Y[Ⅱ]和q L分别比普通化肥处理高22.2%和39.5%,Fv/Fm在叶龄60天时比普通化肥处理高18.7%,而NPQ值在叶龄45天时普通化肥比有机肥处理高23.3%。叶绿体内孕育的淀粉粒随叶龄的增加而逐渐膨大,期间伴随着淀粉粒在叶绿体中所占的面积比例(Ra值)越来越大,两处理Ra值差异明显,尤其是在叶龄45天时,化肥栽培下的烟叶Ra值比有机肥栽培高31.8%。有机肥处理的叶绿体呈梭形,长宽比大,而普通化肥种植的叶绿体形态近圆形,长宽比小。【结论】施用有机肥可显著提高烟叶叶绿素含量及光合速率,且随叶龄的增加,有机肥的作用效果日趋明显。叶绿素荧光参数的差异表明,增施生物有机肥可延缓烟株衰老、提高烟叶光能利用效率。两种施肥方式下,淀粉颗粒Ra值的差异不能说明施用化肥可提高烟叶合成淀粉的能力。与普通化肥处理下的烟叶相比,有机肥可显著提高叶绿体基粒垛叠数大于10的片层占基粒垛叠片层总数的百分比。     

大豆叶绿体转化载体pJY系列的构建及其在烟草上的转化研究

为解决杂交大豆(Glycinemax)制种过程中不育系易与保持系混杂的问题,开展了大豆叶绿体转基因的研究。通过转基因方法在不育系的细胞质中植入筛选标记基因,以区分不育系和保持系。根据已发表的大豆叶绿体序列(GenBankX07675)设计引物,用PCR方法获得两段大豆叶绿体同源重组序列LHRR和RHRR,克隆到质粒pUC19中,并将来源于质粒pTF102的壮观霉素抗性基因aadA克隆到两段同源重组序列之间,以构建大豆叶绿体转化表达载体pJY01。aadA基因的启动子Prrn和终止子psbA基因3′序列,分别从烟草叶绿体基因组中扩增而来。在此基础上,将草丁膦抗性基因或绿色荧光蛋白与GUS的融合蛋白基因克隆到该载体上,得到pJY03与pJY04,并初步应用于烟草(Nicotianatobacum)的叶绿体转化,获得了具壮观霉素抗性的绿色愈伤和幼苗,PCR扩增出aadA基因的条带,并在激光共聚焦扫描下检测到GFP的表达。     

两个叶绿体基因位点的DNA条形码在桉属种间鉴定中的应用

 对桉属的13个样本(11个种、1个人工杂交种和1个优良无性系) 的trnH-psbA基因间隔区 的序列进行了比对和分析, 13个桉属样本的trnH-psbA长度范围为538～576 bp, 序列排序的一致性长度为590 bp。共检测出了52个变异性状, 其中46个变异性状为碱基置换, 6个性状为插入或缺失。同时, 对桉属11个样本的rpl2-trnH基因间隔区(大单拷贝与反向重复接头) 区域进行了序列分析, 分析表明, 11个桉属样本的rpl2-trnH长度范围为79～149 bp, 序列排序的一致性长度为154 bp。共检测出了19个变异性状, 其中4个性状为插入或缺失, 15个变异性状为碱基置换。尾叶桉优良无性系的trnH-psbA和rpl2-trnH序列与尾叶桉仅1个位点的碱基置换; 与巨尾桉、巨桉进行比较, 尾叶桉优良无性系的trnH-psbA序列有27 bp 的插入, 以上4 个近缘样本在rpl2-trnH 区域的序列差异为12 个碱基置换。研究表明, 通过两个cpDNA基因位点序列不仅可以将桉属不同种进行区分, 而且也可以区分尾叶桉优良无性系与尾叶桉。因此, 本研究涉及的两个叶绿体基因组位点序列在建立桉树植物种间鉴定的DNA条形码方面具有潜在的应用价 值。