Regulation Culture on Cytological，Biochemical and Physiological Characteristics of Somatic Carrot Em

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超干种子耐贮藏性的细胞学及生理生化基础

种子超干贮藏是近年来种子生物学研究和植物种质资源保存领域的研究热点。本文综述了种子超干贮藏研究的进展 ,包括 :(1)超干种子的细胞和亚细胞结构变化 ;(2 )超干处理对种子水分状态的影响以及与劣变反应速率的关系 ;(3)超干种子中的自由基伤害和有毒物质的积累 ;(4)超干种子中的内源抗氧剂 ;(5 )糖类物质以及两性物质对极度脱水种子细胞的保护。此外 ,还对此领域的研究进行了展望     

甲醇对植物的作用及其生理机制

甲醇是植物生长发育和代谢过程中体内产生的最简单的一碳化合物之一,与植物的很多生理过程(如光合作用、C1-四氢叶酸和某些植物激素生物合成以及植物耐逆性等)密切相关。本文对近年来国内外有关植物中甲醇的产生与释放途径、体内代谢、外施甲醇对植物的效应及其生理机制等方面研究进行了综述,并提出存在的问题和今后研究方向。     

Physiological,Biochemical and Cytological Changes in Senescing Corolla of Four-O'clock Flower

Senescing corolla of Four-O′ clock flower (Mirabilis jalapa L. ) was accompanied by a decline in the contents of RNA and protein as well as an increase of free nucleotides and amino acid but with no change in DNA content. SDS-PAGE of proteins showed a gradual reduction in the molecular weight of protein. RNase activity increased obviously but there was no change of DNase activity. Prior to flower wilting the peroxidase activity increased and the rate of ethylene production reached it's the highest level. When isolated corolla lobes were floated on distilled water, RNase activity and ethylene production increased dramatically in a few hours. But if they were floated on cycloheximide solution, the increase of Rnase activity and ethylene production were completely inhibited. Cycloheximide (0.5–1.0 ppm) could extend the longevity of Four-O′clock flower outtings. Electron micrographs showed that starch grain disappeared after flowering. However, no significant disintegration is observed in cell nucleus and mitochondria during senescence of corolla.     

Physiological and Biochemical Characteristics of Sugar Beet Plants Grown at an Increased Carbon Dioxide Concentration and at Various Nitrate Doses

Three-week-old sugar beet (Beta vulgaris L.) seedlings were grown for an additional four weeks under controlled conditions: in river sand watered with a modified Knop mixture containing one half-fold (0.5N), standard (1N), and or threefold (3N) nitrate amount, at the irradiance of 90 W/m² PAR, and at the carbon dioxide concentrations of 0.035% (1C treatment) or 0.07% (2C treatment). The increase in the carbon dioxide concentration and in the nitrogen dose resulted in an increase in the leaf area and the leaf and root dry weight per plant. With the increase in the nitrogen dose, morphological indices characterizing leaf growth increased more noticeably in 1C plants than in 2C plants. And vice versa, the effects of increased CO₂ concentration were reduced with the increase in the nitrogen dose. Roots responded to the changes in the CO₂ and nitrate concentrations otherwise than leaves. At a standard nitrate dose (1N), the contents of proteins and nonstructural carbohydrates (sucrose and starch) in leaves depended little on the CO₂ concentration. At a double CO₂ concentration, the content of chlorophyll somewhat decreased, and the net photosynthesis rate (P _n) calculated per leaf area unit increased. An increase in the nitrogen dose did not affect the leaf carbohydrate content of the 1C and 2C plants except the leaves of the 2C-3N plants, where the carbohydrate content decreased. In 1C and 2C plants, an increase in the nitrogen dose caused an increase in the protein and chlorophyll content. Specific P _n values somewhat decreased in 1C-0.5N plants and had hardly any dependence on the nitrate dose in the 2C plants. The carbohydrate content in roots did not depend on the CO₂ concentration, and the content was the highest at 0.5N. Characteristic nitrogen dose-independent acclimation of photosynthesis to an increased carbon dioxide concentration, which was postulated previously [1], was not observed in our experiments with sugar beet grown at doubled carbon dioxide concentration.     

Effects of Enhanced UV-B Radiation and Tropospheric Ozone on Physiological and Biochemical Characteristics of Field Grown Wheat

Non-vernalized scions were grafted onto vernalized stocks in winter rape (Brassica napus L. var. oleifera, cv. Górczański). The grafted plants were subjected to electric current (30 V for 30 s or 6 V for 24 h) and the percentage of flowering scions was recorded. The negative polarity with cathode (−) attached to the scion and anode (+) left close to the roots inhibited greatly the percentage of flowering. The reverse polarity enhanced flowering markedly under short days and only slightly promoted flowering under long days. Attachment of electrodes without passing a current had no effect on flowering. This revised version was published online in July 2006 with corrections to the Cover Date.     

叶面喷施甲醇和乙醇对万年青生理特性的影响

为了比较甲醇和乙醇对植物生理特性的影响,分别用5％(V/V)的甲醇和乙醇均匀喷洒于温室条件下盆栽培养的万年青叶片上,以喷施蒸馏水的植物为对照,每周喷施2次,喷施3周后分析这两种醇对万年青叶片生长、生理特性及相关光合基因表达的影响.结果表明,喷施甲醇和乙醇均增加了万年青叶片鲜重、可溶性总蛋白质含量、气孔导度、蒸腾速率、胞间CO2浓度、净光合速率、叶绿素a、b及总叶绿素的含量,降低了过氧化氢的含量,提高了质膜H+ ATPase及H+泵活性,并且乙醇的作用效果比甲醇更加明显.RT-PCR分析结果表明,光合作用相关基因叶绿素a/b结合蛋白基因(Cab)和铁氧还蛋白-2编码的基因(2-FdO)在处理12h时被甲醇抑制但却被乙醇诱导,72 h时被甲醇诱导但却被乙醇抑制;两种醇均诱导光系统Ⅱ反应中心PsbP家族蛋白编码基因(PsbP)的表达.由此推测甲醇和乙醇可能在植物中作为信号分子起作用,且乙醇的刺激效果比甲醇更加显著.     

人工老化处理对小麦种子生理生化特性的影响

为探明小麦种子在贮藏过程中的生理生化变化规律及合适的老化处理条件,本研究采用高温高湿人工加速老化的方法,对5个非糯小麦和5个糯小麦品系的种子在50℃和90%相对湿度条件下分别处理0、2、4、6、8 d。结果表明:种子发芽率随着老化处理时间的延长而逐渐降低,电导率呈先降后升的趋势;非糯小麦种子的可溶性糖含量随着处理时间的延长呈先降后升、最后下降的趋势,糯小麦种子的可溶性糖含量随着处理时间的延长而逐渐上升;CAT、POD和SOD活性在处理2 d时降到最低,之后保持不变;可溶性蛋白质含量在处理2 d时有所增加,此后随处理时间的延长呈下降趋势;MDA含量随着处理时间的延长呈先降后升、最后降低的趋势。     

Cd胁迫对紫花苜蓿种子发芽及幼苗生理生化特性的影响

以‘甘农3号’紫花苜蓿(Medicago sativa L.cv.‘Gannong 3’)品种为试验材料,研究不同浓度Cd胁迫对紫花苜蓿种子萌发及幼苗生理生化特性的影响。结果显示:(1)Cd胁迫显著抑制紫花苜蓿种子萌发及幼苗生长,种子发芽势、发芽率及幼苗的胚芽长、胚根长和干重均随着Cd处理浓度提高显著降低,且对发芽势的抑制作用大于发芽率,对胚根生长的抑制作用大于胚芽。(2)Cd胁迫第4d时,萌发种子中蛋白水解酶的活性受到显著抑制,可溶性蛋白和可溶性糖含量显著降低。(3)Cd胁迫第10d时,随着Cd胁迫浓度的增加,苜蓿幼苗的超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、愈创木酚过氧化物酶(GPX)活性均先升高后降低,过氧化氢酶(CAT)活性持续下降,超氧阴离子自由基产生速率、H2O2含量和丙二醛(MDA)含量均显著增加。研究表明,低浓度Cd胁迫下,苜蓿幼苗抗氧化系统清除活性氧的能力上升,高浓度Cd胁迫下,苜蓿幼苗抗氧化系统活性下降,膜脂过氧化程度加剧,活性氧的过量积累是Cd伤害苜蓿幼苗和其生物量下降的主要原因。     

一碳代谢关键酶——甲醇脱氢酶的研究进展与展望

甲醇和甲烷等一碳原料来源广泛,价格低廉,是生物制造的理想原料.甲醇脱氢酶(Methanol dehydrogenase,MDH)催化甲醇生成甲醛是一碳代谢的关键反应.目前已从天然甲基营养菌中发现了多种利用不同辅因子,具有不同酶学性质的MDH.其中,烟酰胺腺嘌呤双核苷酸(NAD)依赖型MDH被广泛应用于构建人工甲基营养菌...     

亚麻耐盐性愈伤组织的生理生化特性

以亚麻(双亚5号)耐盐愈伤组织为材,以同种亚麻普通愈伤组织为对照,分别经含0~250 mmol·L^-1 NaC1的培养基培养20 d后,比较含水量、MDA含量、POD酶活、SOD酶活、EST同工酶谱、POD同工酶谱及SOD同工酶谱。结果表明：亚麻耐盐组愈伤组织与对照组愈伤组织在多方面存在明显差异,前者含水量均高于后者;丙二醛含量也高于后者,但变化幅度不大;POD酶活均高于对照组;酯酶同工酶谱不同于对照组,酯酶酶活量均高于对照组;POD同工酶谱比对照组多一条带,且酶活均高于对照组;SOD同工酶谱与对照组一样多,但酶活均高于对照组,且平稳。这为进一步筛选亚麻耐盐突变细胞系奠定了良好的基础。     

病毒病害对滇黄精生理生化特性、产量及品质的影响

【目的】明确病毒病害对滇黄精生长发育、产量及品质的影响,为深入研究病毒的致病机理提供依据。【方法】试验以滇黄精抗病和感病植株为研究对象,探讨被病毒侵染后对滇黄精叶片光合气体参数、叶绿素含量、叶绿体超微结构、超氧化物歧化酶（superoide dismutase,SOD）、过氧化物氧化酶（peroxidase,POD）、多酚氧化酶（polyphenol oidase,PPO）及苯丙氨酸解氨酶（phenylalanine ammonia lyase,PAL）以及块茎生物学性状,有效化学成分含量测定和分析。【结果】滇黄精受病毒侵染后,其光合作用减弱,为Pn降低了2倍左右,叶片气孔导度降低了11.25%,CO2int降低了5.79%;叶片细胞的细胞膜发生强烈的脂膜过氧化反应,MDA的含量升高了2倍以上,细胞质中散布线状病毒粒子及其聚集形成的大量内含体,细胞内叶绿体结构受损严重,部分已发生解体;叶绿素发生降解,叶绿素a和b的含量极显著减低,减少了22.97%和 35.38%。同时,其体内的防御反应被激活,防御酶包括SOD、POD、PPO、PAL的活性极显著升高,PPO升高了1.6倍。进而滇黄精地下根茎的膨大和嫩芽的生长受阻,单株鲜重降低了48.08%,根茎中多糖的相对含量减少了6.97%,皂苷含量减少了23.31%,黄酮含量减少了15.32%,总酚的含量减少了11.07%。【结论】滇黄精受病毒侵染后,细胞膜受损,防御反应被激活,光合作用减弱,最终导致产量和品质显著降低。     

亚硒酸钠和硒酸钠对小白菜生长生理特性的影响

以小白菜品种'秦白2号'为材料,采用盆栽试验研究了不同浓度亚硒酸钠[Se(IV)]和硒酸钠[Se(VI)]胁迫对小白菜生长生理特性的影响及其生理机制,为土壤硒污染修复及其合理开发利用提供理论依据.结果表明,Se(IV)≤10.0 mg·kg-1时,小白菜的叶长、叶宽显著下降,而生物量没有受到显著影响;Se(VI)≤1.0 mg·kg-1时,叶长、叶宽、生物量没有显著变化;更高浓度处理时,叶长、叶宽、生物量均随外源Se(IV)和Se(VI)处理浓度的增大而急速下降.Se(IV)≤40.0 mg·kg-1和Se(VI)≤20.0 mg·kg-1处理均对小白菜叶片叶绿素含量无显著影响,但更高浓度外源Se(IV)和Se(VI)却显著抑制了叶绿素合成.低浓度外源Se(IV)和Se(VI)均使小白菜叶片谷胱甘肽过氧化物酶(GSH-Px)活性上升,膜质过氧化物(MDA)含量下降,对超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性及脯氨酸含量无显著影响;高浓度硒使MDA含量、脯氨酸含量及SOD活性上升,而使GSH-Px活性和CAT活性下降;外源Se(IV)和Se(VI)均使过氧化物酶(POD)活性降低.研究发现,低浓度外源Se(IV)和Se(VI)均提高了小白菜的抗氧化作用,从而促进小白菜叶片叶绿素的合成和生长,高浓度时则相反;低浓度硒的抗氧化作用和高浓度硒的过氧化作用均以Se(VI)大于Se(IV).说明硒酸钠的有效性和毒害作用均大于亚硒酸钠.     

采前喷钙对芍药切花生理生化的影响

以芍药切花品种'杨妃出浴'为试验材料,于采前不同时期喷施4%的CaCl2溶液,以不喷钙切花为对照,观察、测定芍药切花瓶插寿命、花径以及瓶插期间生理生化的变化,已探讨采前喷钙及喷钙时期对芍药切花衰老的影响.结果显示,采前喷钙处理有利于芍药切花保持水分平衡,增加切花花径和鲜重,降低切花体内可溶性蛋白质的降解速度,减缓膜透性的增大,延长切花寿命.研究表明,以采前21 d喷钙为最佳处理,可以延长芍药切花瓶插寿命2.3 d.     

超大型烟草突变株的生理生化特征和分子生物学鉴定

超大型烟草突变株再生植株高度是野生型的2．2倍,叶片数是野生型的3．3倍,呈现晚花发育特征;叶片气孔保卫细胞中叶绿体数是野生型的1．3倍,叶绿素a、b和叶绿素总量均高于野生型,可溶性蛋白质含量是野生型的1．18倍,过氧化物酶、细胞色素氧化酶同工酶电泳图谱上有一定差异;可溶性蛋白SDS-PAGE电泳图谱上比野生型少4条谱带;RAPD结果表明突变体在DNA水平上确实发生了变化,DDRT-PCR结果显示出两者在基因表达上有差异。突变株再生植株可以开花结实,植株高大、叶数多,晚花的特征可以稳定遗传。     

Characteristics of Arsenic Accumulation by Pteris and non-Pteris Ferns

This research was conducted to understand the mechanisms of arsenic hyperaccumulation in Pteris vittata by comparing the characteristics of arsenic accumulation in Pteris and non-Pteris ferns. Seven Pteris (P.vittata, P. Cretica Rowerii, P. Cretica Parkerii, P. Cretica Albo-lineata, P. Quadriavrita, P. Ensiformis and P. Dentata) and six non-Pteris (Arachnoides simplicor, Didymochlaena truncatula, Dryopteris atrata, Dryopteris erythrosora, Cyrtomium falcatum, and Adiantum hispidulum) ferns were exposed to 0, 1 and 10 mgL⁻¹ arsenic as sodium arsenate for 14-d in hydroponic systems. As a group, the Pteris ferns were more efficient in arsenic accumulation than the non-Pteris ferns, with P. vittata being the most efficient followed by P. cretica. When exposed to 10 mg L⁻¹ As, arsenic concentrations in the fronds and roots of P. vittata were 1748 and 503 mg kg⁻¹. Though not all Pteris ferns were efficient in accumulating arsenic, none of the non-Pteris ferns was an efficient As accumulator (the highest concentration being 452 mg kg⁻¹). The fact that frond arsenic concentrations in the control were highly correlated with those exposed to As (r ² = 0.76–0.87) may suggest that they may be used as a preliminary tool to screen potential arsenic hyperaccumulators. Our research confirms that the ability of P. vittata to translocate arsenic from the roots to the fronds (73–77% As in the fronds), reduce arsenate to arsenite in the fronds (>50% AsIII in the fronds), and maintain high concentrations of phosphate in the roots (48–53% in the roots) all contributed to its arsenic tolerance and hyperaccumulation.     

Changes in Growth,Developmment,and Physiological and Biochemical Activity of Asparagus Seedlings Grown from Space Flown Seeds

Asparagus seeds were sent on board retrievable satellites and they were flown in space for 8 days. Experiments were conducted in fields and laboratory after the seeds returned to the earth. Comparative studies were made on the growth and development patterns of plants growing from space flown seeds and controls kept on the earth. Changes in physiological and biochemical characteristic of the seedlings were also studied. The results obtained are summarized as follows: (1) Space flight markedly raised the germination rate of seeds as compared with the controls kept on the earth. After 5 days of imbibition, 40% of the space flown seeds germinated while the germination rate for ground controls was only 22.5%. After 6 days of imbibition the germination rate of space flown seeds was 65 % and that of ground controls 40%. After 10 days of imbibition, the rates rose to 87. 5% and 72. 5% respectively. The seedlings from space flown seeds grew in fields much faster than ground controls. The yield of tender stems of the former was 34% higher than the latter. (2) An assay on respiration showed that the respiratory intensity of space seedlings was 61% higher than that of ground controls. This indicated that the vigor of seeds enhanced under space conditions, accelerating the germination of seeds and growth of seelings. (3) The proline content of space seedlings was 33% higher than that of the ground controls. At the same time, the permeability of the plasma membrane of the space seedlings was markedly lower than that of the ground controls. The content of aspartic acid in plants grown from space seeds was slightly higher than in ground controls while the content of asparagus was markedly lower.     

岷江干旱河谷区典型灌木对干旱胁迫的生理生化响应

以岷江干旱河谷区6种典型山地灌木[沙棘(Hippophae rhamnoides)、羊蹄甲(Bauhinia faberi)、白刺花(Sorphora davidii)、锦鸡儿(Caragana arborescens)、三颗针(Berberis sargentiana)、黄栌(Cotinus szechuanensis)]为试材,采用盆栽试验研究了土壤自然干旱胁迫对苗木叶片抗氧化保护酶活性、膜伤害程度以及渗透调节物质的影响,探讨植物应对土壤干旱逐渐加剧的生理生态适应机理。结果表明,植物不同抗氧化保护酶对干旱胁迫及随之而来的氧化胁迫的响应存在一定差异。各灌木的超氧化物歧化酶随着干旱胁迫的增强呈先上升后下降,过氧化物酶在整个胁迫期间表现为逐渐升高,过氧化氢酶的升高则主要发生在胁迫的中后期,表明不同胁迫时期对植物体起主导作用的保护酶不同,三者表现为相互协调的作用方式。随着干旱胁迫的增强,各灌木的丙二醛呈缓慢增加趋势,细胞的膜脂过氧化作用逐渐加强,植物开始遭受一定程度的毒害。沙棘和羊蹄甲叶片的质膜相对透性随胁迫的增强呈现先升后降最终回到初始水平的特点,表明植物可以通过干旱锻炼获得一定的抗旱能力。白刺花和黄栌叶片的质膜相对透性在胁迫的0—4 d保持不变,从8 d开始大幅上升并一直维持在较高水平,说明胁迫初期植物细胞膜的结构和功能还很完整,生理活动仍能正常进行,但从中期开始细胞膜遭受严重破坏。随着干旱胁迫的增强,各灌木叶片的脯氨酸总体均呈增加趋势,表明干旱胁迫下植物通过积累脯氨酸以提高细胞的渗透调节能力。主成分分析表明,6种灌木的抗旱能力由强到弱依次为:羊蹄甲、沙棘、锦鸡儿、黄栌、白刺花、三颗针。综合分析表明,干旱河谷区几种典型灌木可通过提高抗氧化酶活性并积累渗透调节物质对干旱胁迫进行积极的反馈,以减弱逆境胁迫下活性氧的危害,提高细胞的渗透调节能力,减轻细胞遭受的损伤。