连续流动在植株全氮测定中的应用

研究建立了一种快速测定植株全氮的有效方法。方法检测范围为0~90 mg/L,回归系数r=0.9996,检测限为0.03 mg/L,方法回收率为100.7%~101.6%,通过对标准物质的检测,结果均在标准误差允许范围内,绝对偏差为0.8%~1.9%,通过连续流动与凯氏定氮法测定实际植株样品,测定结果绝对偏差在0.13%~1.31%之间,表明该方法检测稳定可靠;同时,相对于凯氏定氮法,每个样品检测仅需1 min,单个样品检测试剂消耗总量仅3.65 mL,氢氧化钠用量仅为凯氏定氮法的30%。     

九孔鲍不同器官DNA相对含量与细胞周期的分析

应用流式细胞术测定了30只九孔鲍Haliotis diversicolor supertexte不同器官DNA的相对含量,比较了各器官的细胞周期差异。结果表明,相同条件下生长的2龄九孔鲍足、上足触手、上足、头触角、外套膜、鳃和眼柄组织的DNA含量存在差异,其中头触角的DNA含量较外套膜组织低15．19％。从各器官细胞周期的时相比例分析看,九孔鲍各器官细胞的同步性较好,G1期时相比例都高于80％,其中鳃G1期比例最高,达到88．62％,头触角中G2／M期时相比例最高,达到11．18％,不同器官各细胞时相的比例存在差异。     

GPC-HPLC-LC/MS测定植物组织中的赤霉素

以胡杨叶片、烟草组培苗及萌发绿豆为材料,研发了利用凝胶渗透色谱(GPC)纯化、液相质谱(LC-MS)定性、 高效液相色谱(HPLC)定量测定植物组织中赤霉素(GAS )的方法。植物样品用80% 甲醇研磨后4℃浸提过夜,抽 滤离心(5 000 r/ min, 20 min)、滤液加2 滴浓氨水浓缩至水相,冻融离心,上清液,调pH 2.5 ~3.0 乙酸乙酯萃取,过 Sep-pak C18 小柱,用含5% 甲醇的CH2 Cl2 溶解样品,经0.22 m 滤膜过滤后,通过GPC 纯化、LC-MS 定性,利用 HPLC 外标曲线法定量。经检测:胡杨叶片中GA3 含量为1 162.789 8 ng/ g 鲜质量; 烟草中GA3 含量为920.906 7 ng/ g 鲜质量; 萌发绿豆中GA3 含量为700.923 6 ng/ g 鲜质量。      

Cytokinins in the soluble RNA of plant tissues

The cytokinin, N(6)-(Delta(2)-isopentenyl) adenosine occurs in the soluble RNA of yeast and mammalian tissue and has now been detected in plant soluble RNA. A hydroxylated derivative of this cytokinin 6-(cis-4-hydroxy-3-methylbut-2-enylamino)-9-,beta-D-ribofuranosylpurine has also been identified as a constituent of plant soluble RNA.     

不同植物组织RNA提取方法的比较分析

不同的植物组织都有较优化RNA提取方法。本文针对蜡质的红掌叶片、含糖较多的百合花瓣、含色素较多的万寿菊花瓣,使用改良CTAB法、Trizol法、快速RNA提取试剂盒法提取RNA,比较提取效果,以确定适合几种植物组织的最优RNA提取方法。结果表明:改良CTAB法提取的红掌叶片总RNA,Trizol法提取的百合花瓣总RNA和万寿菊总RNA,28SRNA和18SRNA条带都较清晰,且28SRNA亮度较18SRNA明亮,效果较好,部分RNA提取试验中5SRNA也较明亮,说明提取的总RNA有部分降解,但总RNA质量符合后续试验要求。RT-PCR检验符合上述结论。     

UPLC-MS/MS测定植物组织中植物激素的含量

目的植物激素在植物生长发育和响应生物和非生物胁迫过程中起着非常重要的作用,研究植物激素的合成、运输、代谢和分子作用机理,需要对植物激素进行定量分析。针对植物激素在大多数植物组织中的含量很低,性质不稳定,与其共存的次生代谢产物背景干扰严重,此外有些植物材料非常珍稀,材料量少的问题,以毛白杨叶片为材料,建立了超高效液相色谱?串联质谱（UPLC-MS/MS）同时测定植物组织中吲哚乙酸（IAA）、脱落酸（ABA）、赤霉素（GA₃）、茉莉酸（JA）和水杨酸（SA）的新方法,为植物激素的研究提供技术支撑。方法在用异丙醇、水和盐酸（2∶1∶0.002,v∶v∶v）混合液4 ℃提取激素时,定量加入IAA、ABA、GA₃、JA和SA内标（2H₅-IAA、2H₆-ABA、2H-JA和2H₅-SA各10 ng,2H₂-GA₃ 20 ng）,激素提取液经二氯甲烷萃取后,UPLC-MS/MS定量测定。乙腈?0.1%乙酸水溶液为流动相,梯度洗脱,流速 0.8 mL/min,柱温30 ℃,C₁₈色谱柱分离,多反应监测（MRM）、电喷雾电离源（ESI）负离子模式下进行分析,内标曲线法定量。结果5种植物激素在5 min内实现完全分离,检出限为0.01 ~ 0.05 pg/g,定量限为0.05 ~ 0.15 pg/g。在实验所采用的浓度范围内线性相关系数r在0.999 4 ~ 0.999 9之间,精密度和重现性均较好,峰面积的相对标准偏差为1.1% ~ 3.9%。经检测毛白杨叶片中IAA、ABA、GA₃、JA、SA的含量分别为（74.38 ± 4.62）ng/g、（193.80 ± 6.04）ng/g、（674.67 ± 18.08）ng/g、（286.62 ± 7.48）ng/g、（746.02 ± 13.93）ng/g。结论本法操作简单,灵敏度高,分析时间短,适用于多种植物激素的测定。      

反相高效液相色谱法测定植物组织中的水杨酸

以五角枫叶片为实验材料,经预处理后用反相高效液相色谱测定了植物组织中水杨酸的含量.该方法摸索出了使水杨酸与其他酸性（或杂质）组分很好分离的液相色谱条件,建立了植物组织中水杨酸的定性定量方法.用该方法测定水杨酸标样的回收率高于95%,精密度和重现性均较好（相对标准偏差为0.42%）.用该方法对实际植物样品的分析也取得了较理想的结果.      

5个重庆地方猪种遗传多样性的微卫星分析

目的通过微卫星标记评估8个安徽地方猪品种的遗传多样性。方法采用PCR和聚丙烯酰胺凝胶电泳对FAO-ISAG联合推荐的15个微卫星标记进行分型,并计算有效等位基因数 (N_e)、期望杂合度 (H_e)、多态信息含量 (PIC)、F统计量和遗传距离等参数,探讨品种间的遗传多样性和遗传关系。结果15个微卫星标记共检测到272个等位基因,平均有效等位基因数9.561 2个。8个品种的有效等位基因数在2.445 1~3.786 6之间,期望杂合度在0.532 0~0.714 8之间,多态信息含量在0.369 8~0.890 6之间。F统计量和基因流 (N_m) 分析表明：安徽地方猪品种间存在一定程度的近交和基因流动。基于Nei氏遗传距离 (D_s) 构建系统发生树显示：8个地方猪种可分为两类：一类为皖南花猪;另一类又聚为两小支,一小支为安庆六白猪、圩猪和霍寿黑猪,另一小支为皖北猪、皖南黑猪、枞阳黑猪和定远猪。结论8个安徽地方猪种遗传多样性丰富,群体内存在一定程度的近交和基因流动。结果为安徽地方猪种的保护和利用提供了理论依据。     

Application of image analysis to plant cell suspension cultures

Cell suspension culture is a promising tool for developing high-efficiency systems for transplant or metabolite production. To make the best use of this technique, it is essential to maintain high quality in cultured cells. Quality evaluations, which select cultured cells or cell lines with desirable properties, are necessary for cell quality maintenance. Image analysis has good potential for realizing simple, non-invasive and objective quality evaluations in cell suspension cultures. Factors used so far to evaluate cultured cells relate to color, growth rate, shape, aggregate size distribution, and macroscopic texture. Both microscopic and macroscopic images are available for analysis. Microscopic image analysis has advantages over directly observing individual cells, cell aggregates or differentiated cell masses. However, it has problems with image acquisition. On the other hand, macroscopic images viewed with normal or macro lenses whose fields of view cover almost one whole culture have an advantage in imaging, as images can be acquired from outside the culture vessel without special devices. They have also been used for quality evaluation of cell suspensions using cell quantification or texture analysis.     

如何控制植物组织培养中褐变的产生

褐变在植物组织培养过程中普遍存在,其诱发原因比较复杂,不同植物可采取不同的方法进行防止或减轻其发生.     

S phase of the cell cycle

In each cell cycle the complex structure of the chromosome must be replicated accurately. In the last few years there have been major advances in understanding eukaryotic chromosome replication. Patterns of replication origins have been mapped accurately in yeast chromosomes. Cellular replication proteins have been identified by fractionating cell extracts that replicate viral DNA templates in vitro. Cell-free systems that initiate eukaryotic DNA replication in vitro have demonstrated the importance of complex nuclear architecture in the control of DNA replication. Although the events of S phase were relatively neglected for many years, knowledge of DNA replication is now advancing rapidly in step with other phases of the cell cycle.     

Carbon flow in plant microbial associations

Measurement of the distribution of the photosynthesis product in the symbiotic association of a legume, a mycorrhizal fungus, and nitrogen-fixing bacteria showed that the fungus incorporated 1 percent of the photosynthesis product and respired 3 percent. The nodules of a 5-week-old plant utilized 7 to 12 percent of the photosynthesis product. The legume compensated in partfor the needs of its microbial partners through increased rates of photosynthesis.     

Rapid regulation of light harvesting and plant fitness in the field

We used Arabidopsis thaliana mutants to examine how a photosynthetic regulatory process, the qE-type or DeltapH-dependent nonphotochemical quenching, hereafter named feedback de-excitation, influences plant fitness in different light environments. We show that the feedback de-excitation is important for plant fitness in the field and in fluctuating light in a controlled environment but that it does not affect plant performance under constant light conditions. Our findings demonstrate that the feedback de-excitation confers a strong fitness advantage under field conditions and suggest that this advantage is due to the increase in plant tolerance to variation in light intensity rather than tolerance to high-intensity light itself.     

四种真菌基因组编码的细胞壁降解酶生物信息学分析

为了比较病原性真菌和非病原性真菌基因组编码的植物细胞壁降解酶,用BLAST(Basic Local Alignment Search tool)结合人工二次筛选的方法确定了四种真菌基因组编码的多种植物细胞壁降解酶,并用SignalP来判断细胞壁降解酶能否被分泌到细胞外.结果表明病原性真菌和非病原性真菌基因组编码的植物细胞壁降解酶在种类和数量上存在着明显的差异,其中E3(endoglucanase Ⅱ)仅由病原性真菌基因组编码,而且能够被分泌到细胞外,可能与病原性真菌对植物的致病性有着密切的关系.     

Rapid changes in the hydrologic cycle of the tropical Atlantic during the last glacial

Sedimentary time series of color reflectance and major element chemistry from the anoxic Cariaco Basin off the coast of northern Venezuela record large and abrupt shifts in the hydrologic cycle of the tropical Atlantic during the past 90,000 years. Marine productivity maxima and increased precipitation and riverine discharge from northern South America are closely linked to interstadial (warm) climate events of marine isotope stage 3, as recorded in Greenland ice cores. Increased precipitation at this latitude during interstadials suggests the potential for greater moisture export from the Atlantic to Pacific, which could have affected the salinity balance of the Atlantic and increased thermohaline heat transport to high northern latitudes. This supports the notion that tropical feedbacks played an important role in modulating global climate during the last glacial period.     

应用分光光度法测定植物组织中的氰化物含量

建立了一套利用分光光度法测定植物组织内氰化物含量的实验程序,该程序包括氰化物的吸收、反应和吸光度测定等步骤,测定波长为550 nm.用该法测定的结果表明水稻(秀水11)干种子内几乎没有游离态的氰化物,但氰化物含量会随着种子萌发进程而不断升高.     

植物纤维素合成酶基因和纤维素的生物合成

目的系统鉴定和分析小麦纤维素合成酶(CesA)基因家族成员,为进一步阐明小麦CesA基因家族的生物学功能奠定理论基础。方法利用生物信息学方法在小麦全基因组上系统鉴定小麦CesA (TaCesA)基因家族的成员。对小麦CesA基因的系统发育、染色体位置和转录组进行分析。预测TaCesAs基因结构、保守基序、顺式元件、蛋白质特征和亚细胞定位,并对小麦及其亚基因组供体中CesAs同源基因进行比对。结果共鉴定出21个TaCesA基因,分为3组(a、b和c)。基因结构分析发现TaCesA含有多个内含子,但部分基因非翻译区(UTR)结构存在缺失。TaCesA基因与其亚基因组供体关系保守。TaCesAs的上游包含45个与生物胁迫/非生物胁迫、生长发育和植物激素相关的元件,预示这些基因可能参与响应小麦的生物学功能。表达谱结果显示：TaCesA基因在缺磷、高温、低温、干旱、条锈病、白粉病和赤霉病等逆境胁迫中均有响应。结论小麦CesA基因具有保守的基因结构和蛋白结构,且在小麦抵御非生物和生物胁迫中起着重要作用。