河西走廓不同生态型芦苇核酸代谢季节动态研究

分布在甘肃河西走廓的４种生态型芦苇的核酸代谢季节变化有差异,盐化草甸芦苇ＲＮＡ含量持续增加,ＤＮＡ含量相对稳定,其它３种生态型芦苇的ＲＮＡ和ＤＮＡ以５月份为最高,过渡带芦苇的ＲＮＡ含量,沼泽芦苇及沙丘芦苇的ＤＮＡ含量９月份略有增高,盐化草甸芦苇与过渡带芦苇的ＤＮａｓｅ和ＲＮａｓｅ活性５－９月份呈增高趋势。盐化草甸芦苇的ＤＮＡ和ＲＮＡ合成活性不断升高,过度带芦苇和沼泽芦苇的ＤＮＡ和ＲＮＡ合成活性及沙     

芦苇生态型划分指标的主分量及模糊聚类分析

运用主分量分析及模糊聚类的方法首次对包括群落、形态,解剖,生理生化及遗传代谢等４５个指标的不同生态芦苇进行了分析,结果表明,生物量、单株干重、株高,可溶性蛋白质含量、ＲＮＡ含量、ＤＮａａｓｅ和ＲＮａｓｅ活性、Ｋｒａｎｚ结构的有无及土壤ｐＨ值等差异最为显著。４种生态型芦苇中,盐化草甸芦苇与盐化草甸－沙丘过渡带芦苇最相近,其次为沙丘芦苇,沼泽芦苇与其它３种生态相似程度最低。     

不同生境芦苇tRNA的分离纯化及氨酰化特性研究

用苯酚法,ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ＿（２５）柱层析分离并纯化了河西走廊分布的不同生境芦苇的ｔＲＮＡ。用ｔＲ－ＮＡ结合￣３Ｈ－Ｌｅｕ、￣３Ｈ－Ｇｌｙ及￣３Ｈ－Ａｌａ的氨酰化活性研究了四种生境芦苇的ｔＲＮＡ氨酰化特性。结果表明,三种￣３Ｈ－氨基酸的ｔＲＮＡ氨酰化活性在不同生境之间及同一生境芦苇的不同发育时期表现出极大差别;ｔＲＮＡ含量也存在类似的变化,表现在沙生芦苇与沼泽芦苇５－９月份含量均增高,盐化草甸－沙丘过渡带芦苇中ｔＲＮＡ含量均较其它生境芦苇低,而盐化草甸芦苇中以７月份含量最高;蛋白水解酶活性除沙生芦苇９月份降低外,其余三种生境芦苇均呈增高趋势;蛋白质含量在盐化草甸芦苇中与总氨酰化活性变化相一致,而过渡带芦苇与蛋白水解酶活性变化类似,沙生芦苇５月份表现为水解占优势后期则主要与合成有关,沼泽芦苇７、９月份却与水解相关。产生这些结果的原因之一是芦苇代谢对各自生境适应的差异性。     

不同生态型芦苇叶片中多胺浓度和精氨酸脱羧酶活性的季节变化

对分布于甘肃省河西走廊的４种生态型芦苇叶片中多胺浓度和精氨酸脱羧酶活性的季节变化动态进行了比较研究。结果表明,四均含有相同的多胺类别,且随着季节的推移,多胺总量均呈下降趋势。５－９月份,适应干旱胁迫的沙丘芦苇和适应盐胁迫的轻度盐化草甸和重度盐化草甸芦苇保持了较高的ＡＤＣ活性和亚精胺、精胺水平。腐胺的累积,其结果表现为Ｐｕｔ／Ｓｐｄ＋Ｓｐｍ降低,水生芦苇ＡＤＣ活性最低,Ｐｕｔ／Ｓｐｄ＋Ｓｐｍ较高,     

水分胁迫对荔枝叶片氮和核酸代谢的影响及其与抗旱性的关系

水分胁迫下,荔枝叶片蛋白酶活性和Ｐｒｏ 含量增加,ＰＤＨ 活性和可溶性蛋白质含量下降;抗旱性强的品种蛋白酶活性增加的幅度和蛋白质含量下降的幅度小于抗旱性弱的品种, 而ＰＤＨ 活性下降的幅度和Ｐｒｏ 含量上升的幅度均大于抗旱性弱的品种。水分胁迫引起荔枝叶片核酸、ＤＮＡ 和ＲＮＡ 含量下降,ＤＮＡ 含量下降的幅度小于ＲＮＡ 含量下降的幅度;ＤＮａｓｅ 和ＲＮａｓｅ 活性上升,ＤＮａｓｅ 活性上升的幅度小于ＲＮａｓｅ 活性上升的幅度。抗旱性强的品种核酸、ＤＮＡ 和ＲＮＡ 含量下降的幅度以及ＤＮａｓｅ 和ＲＮａｓｅ 活性上升的幅度均小于抗旱性弱的品种。     

水分胁迫对荔枝叶片氮和核酸代谢的影响及其与抗旱性的关系

水分胁迫下,荔枝叶片蛋白酶活性和Ｐｒｏ含量增加,ＰＤＨ活性与可溶性蛋白质含量下降,抗旱性强的品种蛋白酶活性增加的幅度蛋白质含量下降的幅度小于抗旱性弱的品种,而ＰＤＨ活性下降的幅度和Ｐｒｏ含量上升的幅度均大于抗旱性弱的品种。水分胁迫引起荔枝叶片核酸,ＤＮＡ和ＲＮＡ含量下降,ＤＮＡ含量下降的幅度小于ＲＮＡ含量下降的幅度;ＤＮａｓｅ和ＲＮａｓｅ活性上升,ＤＮａｓｅ活性上升的幅度小于ＲＮａｓｅ活性上升的幅     

四种生态型芦苇叶片结构的研究

采用光学显微镜和电子显微镜对４种生态型芦苇（ＰｈｒａｇｍｉｔｅｓｃｏｍｍｕｎｉｓＴｒｉｎ．）叶解剖结构及叶脉维管束鞘细胞超微结构进行了观察研究。结果表明,沼泽芦苇维管束鞘细胞内含物较少,维管束鞘细胞叶绿体呈近圆形,超微结构与典型Ｃ３植物小麦鞘细胞的相似,基粒发育退化,不含淀粉粒;沙丘芦苇鞘细胞内含物较多,鞘细胞叶绿体呈近椭圆形,超微结构与典型Ｃ４植物玉米的相似,具有不发达的基粒;重度盐化草甸芦苇鞘细胞内含物则较沼泽芦苇多,而较沙丘芦苇少,鞘细胞叶绿体形态、超微结构与沙丘芦苇相似;轻度盐化草甸芦苇鞘细胞内含物与沙丘芦苇相似,但是,其鞘细胞含有与沼泽芦苇鞘细胞内叶绿体形态相似的近圆形以及与沙丘芦苇和重度盐化草甸芦苇鞘细胞内形态相似的近椭圆形两种形态的叶绿体。表明生长在同一地区不同环境中的４种生态型芦苇的光合结构发生了深刻的变异,表现出从Ｃ３向Ｃ４进化的明显趋势。     

紫茉莉花衰败过程中的生理,生化及细胞学变化

紫茉莉花（Ｍｉｒａｂｉｌｉｓ ｊａｌａｐａ Ｌ．）衰败过程中发生着大分子物质的降解,水解酶活性的增强及乙烯合成的迅速增加。ＲＮＡ、蛋白质含量迅速减少,游离核苷酸及氨基酸含量增加,ＲＮａｓｅ活性明显增强,ＤＮＡ 含量及ＤＮａｓｅ 活性无明显变化。乙烯合成在花衰败前有明显增强现象。放线菌酮有抑制ＲＮａｓｅ活性增强及乙烯合成的能力,在适当的浓度下有延长紫茉莉花开花时间的作用。花衰败过程伴随着细胞结构的解体,然而细胞核及线粒体并未见有明显的破坏     

黄河三角洲不同生态型芦苇对盐度适应生理的研究：Ⅰ.渗透调节物质 …

山东省黄河三角洲分布４种不同生态型芦伟－淡水沼泽芦苇、咸水沼泽芦苇、低盐草甸芦苇和高盐草甸芦苇。１９９４年的８￣９月份对不同生境生态型芦苇的生长情况、群落组成及优势度进行观测,并测定４种不同生态型芦苇 有机和无机渗透剂以及渗透势和渗透调节能力。结果表明：不同生态型芦苇和多度、盖度、植株高度、叶片含水量和渗透势均随生境盐度的性大而降低;低盐度下的芦苇其渗透剂以Ｋ＾＋和可溶性糖为主,高盐度下以Ｎａ＾＋     

用电镜原位杂交技术对玉米中期染色体中RNA的研究

用生物素标记的玉米１８ＳｒＲＮＡ、小麦５ＳｒＲＮＡ 及ｔＲＮＡ 的ｃＤＮＡ 作为探针,在Ｋ４Ｍ 树脂包埋的玉米（Ｚｅａ ｍ ａｙｓ）根尖超薄切片上进行原位杂交。杂交后,用与１０ ｎｍ 金颗粒相连的亲和素对杂交子在电镜下进行检测。结果发现,在玉米中期染色体中存在有１８ＳｒＲＮＡ、５ＳｒＲＮＡ 和ｔＲＮＡ 分子,这些ＲＮＡ分子在染色体中的分布是随机的,即这些ＲＮＡ 分子在染色体的内部和周边均有分布。５ＳｒＲＮＡ 和ｔＲ－ＮＡ 在染色体中和细胞质中的含量基本相等,而１８ＳｒＲＮＡ 在染色体中的含量则明显高于细胞质。这一结果表明染色体中的ＲＮＡ 一部分来自于核仁,而另一部分则来自于核质     

A survey of photosynthetic carbon metabolism in 4 ecotypes of Phragmites australis in northwest China: Leaf anatomy, ultrastructure, and activities of ribulose 1,5-bisphosphate carboxylase, phosphoenolpyruvate carboxylase and glycollate oxidase

Four ecotypes of Phragmites australis from different habitats in northwest China were examined to compare their photosynthetic characteristics. In a swamp ecotype, the Δ ¹³C value of leaf materials was −34.0‰, and bundle sheath cells contained a small amount of organelles and round-shaped chloroplasts, as being similar to typical C₃ plants. In a dune ecotype, the Δ ¹³C value was −20.9‰ and bundle sheath cells contained oval-shaped chloroplasts with poorly-developed grana. In light and heavy salt meadow ecotypes, Δ ¹³C values were −30.6‰ and −35.6‰, respectively. The shape of bundle sheath chloroplasts in the light salt meadow ecotype was intermediate between those of the swamp and dune ecotypes. Abundance of bundle sheath organelles in the heavy salt meadow ecotype was intermediate. The swamp ecotype had photosynthetic enzyme activities typical of C₃ type plants, whereas the dune ecotype had an increased activity of phosphoenolpyruvate carboxylase (PEPC), a key C₄ enzyme, and a decreased ribulose 1,5-bisphosphate carboxylase (Rubisco) activity. The light salt meadow and heavy salt meadow ecotypes had substantial activities of PEPC, which indicates potential for C₄ photosynthesis. These data suggest that this species evolved the C₃-like ecotype in swamp environments and the C₄-like C₃-C₄ intermediate in dune desert environments, and C₃-like C₃-C₄ intermediates in salt environments.     

四种生态型芦苇叶片结构的研究

The leaf anatomy and uhrastructure of the vascular bundle sheath cells of four ecotypes of reed (Phragmites communis Trin. ) were observed with light and electron microscope. The four ecotypes were the swamp reed, dune reed, heavy salt meadow reed and the light salt meadow reed. It was shown that the intracellular content of the vascular bundle sheath cells of the swamp reed was lower than that of the dune reed; that of the heavy salt meadow reed was between that of the former two reeds and that of the light salt meadow reed and that of the light salt meadow reed was similar to the dune reed. The chloroplasts in the swamp reed were round-shaped with poorly developed grana. Starch grains were not visualized. The uhrastructure of their chloroplasts were similar to those in the typical C3 plants as wheat. By contrast, the chloroplasts in the vascular bundle cells of the dune reed were elliptical with their structure similar to that of the typical C4 plants as maize. These chloroplasts contained some poorly developed grana thykloid. The chloroplasts of the vascular bundle sheath cells in the heavy salt meadow reed were similar to those seen in the dune reed, however, those in the light salt meadow reed appeared to be beth round .and elliptical in shape. The above results suggested a great habitat variation did occur among the four ecotypes of reed in which these exists an obvious evolutional trend from C3 to C4 plants.     

Analyses of Soluble Protein,Total and Free Amino Acids in Leaves of Different Ecotypes of Phragmites communis Growing in the Hexi Corridor

The difference of total and free amino acids and protein extracted from the leaves of four different reed ecotypes growing in Hexi corridor of Gansu Province were investigated. In all of the different reed ecotypes, the content of Asp, Glu, Gly, Leu and Ala in total amino acids were high, while the contents of Ala, Phe, Met and Thr, Pro in total amino acids varied among different reed ecotypes. Albeit Ala, Glu, Asp, Gly and Ser were the chief composition of free amino acids in leaves of all reed ecotypes, but temarkble difference was found in the content of each free amino acid from different reed ecotypes. The content of free Pro in leaves of salt meadow and salt meadow-sand dune transitional zone reed were 3.5 and 1.6 times respectively as much as in leaves of swamp reed. Swamp reed had 11 soluble proteins whereas other three reed ecotypes show that each has 13 soluble proteins. Three “salt adaptation proteins” (66 kD, 40.3 kD, 16.5 kD) were found in leaves of three reed ecotypes with varying degree of salt stress, however, the contents of 3 “salt adaptation protens” showed a negative correlation with the degree of salt stress. There was a large amount of “special protein” (11.7 kD) in leaves of sand dune reeds. These results suggest that the difference in cytogene expression takes a priority basis of adaptation of reed plants to different habitats, while a closer relationship of reeds tolerance to salt or drought stress with Pro accumulation in cells is seen than with the of accumulation stress adaptation protein.     

芦苇耐脱水能力的生理生态学分析

甘肃省河西走廊分布有不同生态环境的芦苇,包括沼泽芦苇、盐化草甸芦苇和沙丘芦苇。盐化草甸芦苇和沙丘芦苇表观出很强的耐脱水能力。 测定与植物耐脱水能力相关的SOD、CAT和POD活力,表现为SOD活力以沙丘芦苇最高,盐化草甸芦苇次之,沼泽芦苇最低,但CAT和POD则以沼泽芦苇高于其它生境芦苇。用聚丙烯酰胺垂直板电泳方法分析这3种酶同工酶谱,结果表明,3种不同生境芦苇的SOD同工酶谱基本相同,均有9条酶带,但沙丘芦苇和盐化草甸芦苇的CAT和POD同工酶带数比沼泽芦苇分别增多3条和2条。这些结果证明,芦苇在自然选择压力下形成的耐脱水能力与基因调控的酶多型性相关。     

Changes in the metabolism of nucleic acids during the growth and senescence of tobacco callus

Changes in DNA and RNA metabolism, DNA composition and RNA species in callus of tobacco ( Nicotiana rustica L. cv. Gansu Yellow Flower) were investigated during the growth and senescence. DNA and RNA contents remained almost unchanged during the callus growth period, but started to decrease synchronously at the time that callus senescence was initiated. Synthesis of DNA and RNA, as measured by incorporation of [³H]-labelled precursor, increased during the growth period and did not decrease until late in senescence. The activities of DNase and RNase (pH 4.5) increased during the early senescence period in accordance with the decrease in the levels of DNA and RNA, but appeared to decrease during late senescence. These results suggest that the decrease in the levels of DNA and RNA in senescing tobacco callus may stem from the increase in the hydrolytic activities of DNase and RNase (pH 4.5) in the early stage of senescence, and that the slowdown of synthesis in the late senescence period may also be a cause. DNA and RNA electrophoresis showed that a low-molecular-weight satellite DNA band disappeared after the onset of senescence and that the nuclear main band DNA gradually decreased, whereas the high-molecular-weight satellite DNA seemed to undergo no significant changes during the senescence period tested. Of the RNA species, 4–5S RNA was far more susceptible to damage during senescence than 25S and 18S rRNA. This suggests different susceptibilities of different DNA and RNA components to damage during the senescence of tobacco callus or alternatively a highly sequenced degradation of DNA and RNA molecules.     

河西走廊芦苇在不同盐渍生境中RuBP羧化酶的比较研究

对不同盐渍生境中芦苇的ＲｕＢＰ羧化酶结构的研究表明,不同类型芦苇的ＲｕＢＰ羧化酶大、小亚基分子量相同,但盐化草甸芦苇和过渡地带芦苇与沼泽芦苇相比,ＲｕＢＰ羧化酶的亲水氨基酸相对含量增加,疏水氨基酸相对含量降低,酶分子被ＰＣＭＢ滴定的ＳＨ基数亦显著减少．表明芦苇的ＲｕＢＰ羧化酶结构发生了变化,反映出该酶有基因表达的环境适应．     

水分胁迫对2种生态型芦苇（Phragmites communis）的可溶性蛋白含量、SOD、POD、CAT活性的影响

研究利用2种抗旱性迥异的芦苇为材料,用PEG6000进行水分胁迫处理,结果表明,抗旱性强的沙丘芦苇（沙芦）的可溶性蛋白含量明显低于沼泽芦苇（水芦）,约为水芦的1／5。但是,在受到20％PEG胁迫时,沙芦的可溶性蛋白含量有所上升,水芦的则稍微下降,在30％PEG胁迫时,水芦的可溶性蛋白含量显著下降,而沙芦则先升后降。沙芦的3种自由基清除酶（SOD、POD、CAT）的活性显著高于水芦。受到水分胁迫后,2种芦苇的SOD、POD、CAT活性或升或降。但是,无论在20％还是30％PEG胁迫条件下,相对水芦而言,沙芦都保持较高的自由其清除酶活性,从而保证其较强的自由基清除能力,减轻自由基对植物细胞生物大分子如DNA、蛋白质、脂肪酸的伤害,维持细胞正常的生命活动,这是沙芦抗旱性强的基础。     

四种生态型芦苇叶中离子分布对生境的生理适应

采用X射线微区分析技术 ,测定了 4种生态型芦苇 (Phragmitesaustralis (CaV .)Trin .exSteud .)叶的表皮泡状细胞、叶肉细胞和叶脉维管束鞘细胞离子的含量。结果表明 :沼泽芦苇的鞘细胞内 ,K 、Na 、Ca2 、Mg2 和Cl-分布均较叶肉细胞和泡状细胞高。沙丘芦苇的泡状细胞中Ca2 分布较叶肉细胞和鞘细胞高 ,而Mg2 在其叶肉细胞 ,以及K 、Na 和Cl- 在其鞘细胞内分布均较高。在轻度盐化草甸芦苇的叶肉细胞内分布较多的Na 和Mg2 ,而在鞘细胞内K 、Ca2 和Cl- 的分布均较叶肉细胞和泡状细胞为高。重度盐化草甸芦苇的泡状细胞内Na 和Mg2 的分布较多 ;同样 ,在叶肉细胞中K 、Ca2 和Cl- 的分布也较多。最后 ,讨论了上述各种离子在不同生态型芦苇叶内分布的状况 ,以及与其环境适应的生理意义。