不同氮肥处理下高温胁迫对夏玉米产量及叶片超微构造的影响

以郑单958为材料,研究高温胁迫对夏玉米产量及叶片超微构造的影响。结果表明,高温处理缩短夏玉米的生育天数,降低夏玉米产量及叶绿素含量。随氮肥增加,高温处理对玉米产量的影响先降低后升高(在310.5 kg/hm^2氮肥下,高温处理玉米产量的降低达到27.2%、31.1%)。高温处理较对照维管束鞘细胞变大,高温处理维管束鞘细胞内的叶绿体出现淀粉粒,对照处理维管束鞘细胞内的叶绿体没有出现淀粉粒。高温线粒体及细胞核(被)膜开始解离,对照处理线粒体及细胞核(被)膜完整,说明高温条件下,玉米对氮的耐受力降低。高温处理叶绿体数、叶绿体基粒数减少及基粒片层数减少,叶绿体面积及叶绿体长/宽比值变小,高温处理较对照线粒体数先增加后减少。高温处理与对照叶肉细胞叶绿体内均未发现淀粉粒。     

枇杷试管苗限制生长保存过程中叶肉细胞超微结构变化的研究

本试验以早钟6号枇杷试管苗为材料,将其分别保存在MS+5 mg/L PP333培养基上和MS培养基(对照)上,采用超薄切片透射电镜对保存的试管苗成熟叶片叶肉细胞进行观察。结果表明:与对照相比,添加5 mg/L的PP333,保存6个月时,明显推迟了叶绿体的变形、移动、叶绿体和线粒体的镶嵌及叶绿体的解体;保存9个月时,叶肉细胞叶绿体结构完整,少数出现解体,淀粉粒明显增大、增多,线粒体和细胞核结构正常。     

花生感染条纹病毒(PStV)后叶片细胞超微结构研究

花生接种PStV后30d取叶片进行超薄切片置于电镜下观察,在花37和白沙1016两个品种发病叶片的叶肉细胞中均发现有多种形状的内含体和病毒粒子的存在;内含体多发现于细胞核周围,有风轮状、柬状、管状和环状等;病毒粒子以柬状或拟晶格状存在,且以高感品种白沙1016叶肉细胞内的含量较多。PStV对叶绿体和线粒体等细胞器的结构有破坏作用,表现为叶绿体畸形,类囊体片层减少,基粒缩小且排列不整齐,并有大量淀粉粒累积,部分线粒体出现肥大和自溶。此外,感病细胞的膜系统松弛,有膜溶解现象,上述病理结构变化均以高感品种白沙1016表现的更为明显。     

草甘膦对大豆叶片超微结构及生化指标的影响

喷施草甘膦后研究大豆莽草酸、叶绿素以及叶片超微结构变化,揭示草甘膦对大豆伤害的机理。喷施草甘膦后,大豆品种东农42叶绿体内产生嗜锇颗粒,片层结构变得稀薄,淀粉粒减少;由于叶绿素含量降低,东农42莽草酸积累;随后叶绿体变形裂解,细胞膜从细胞壁上脱落,细胞瓦解。相比之下,GTS40-3-2叶肉细胞的液泡、叶绿体、叶绿体片层、淀粉粒等先出现一定程度的变化,后恢复;叶肉细胞出现嗜锇颗粒,表现为先增多,后减少,大约1周后消失;莽草酸含量几乎没有变化,叶绿素先下降后恢复,恢复过程需要2周左右。     

国内报刊花生文摘(三)

花生荚果发育过程中子叶细胞的超微结构和酯酶活性的研究/庄伟建…(福建农学院)∥植物学报.-1992,34(5) -333～338 花生荚果子叶生长初期,细胞中质体较多,并不断形成淀粉粒,细胞中酯酶活性低;发育中期,子叶细胞质中出现大量体积较大的脂体,细胞中酯酶活性较强;发育后期脂体数量不再增加,体积略有增大,蛋白体增大较小,但数量增多,脂酶活性仍较强;末期时,蛋白体形态不规则,细胞中脂酶活性减弱。花生脂体起源于细胞质,蛋白体起源于液泡。细胞小脂酶活性的变化可能与脂体发育有关。     

辐射诱发兰花叶艺突变体的叶片叶肉细胞超微结构观察

以未经辐射的全绿植株(TRIR-1)和经辐射诱发叶艺兰植株(TRIR-2)的叶肉细胞为试材,对其全绿植株叶片的正常绿色区、辐射诱变植株叶片的绿色区(TRIR-2′)和白色区(TRIR-2″)叶片叶肉细胞进行细胞超微结构观察。结果表明：(1)TRIR-1叶肉细胞中叶绿体数量最多,TRIR-2′次之,TRIR-2″中无成熟完整的叶绿体;(2) TRIR-1叶肉细胞中的线粒体呈椭圆颗粒状,TRIR-2′中的线粒体外膜破裂、线粒体溶解、嗜锇颗粒数量最多,TRIR-2″中有少量外膜完整的线粒体;(3)TRIR-2″     

甘蓝型油菜黄化(苗)突变体的叶绿素含量及超微结构

用氮离子处理双低高含油量甘蓝型油菜新品系 HDY-8种子 ,M1 出现了一株失绿黄化而后复绿的突变体 ,其 M2 仍有三分之一的植株出现黄化反应。叶绿素含量测定和叶绿体超微结构观察发现 :黄叶、黄绿叶的叶绿素含量明显低于绿叶 ,而叶绿素 a与叶绿素 b的比值又大于绿叶。黄叶细胞内叶绿体数量少 ,形状不规则 ,膜结构已解体 ,无类囊体 ,叶绿体内无淀粉粒 ,嗜锇颗粒较多 ;黄绿叶细胞内叶绿体数目较多 ,形状规则 ,基粒片层清晰可见 ,内有淀粉粒 ;绿叶细胞内叶绿体较多 ,形状规则 ,基粒片层清晰 ,其内淀粉粒多而大 ,嗜锇颗粒较少     

镉对姬松茸菌丝体细胞超微结构的影响

利用透射电镜观察不同浓度水平的Cd2+对姬松茸菌丝体细胞壁、线粒体以及淀粉粒形态结构的影响。结果表明:Cd2+浓度在0-7mg/L范围内,姬松茸菌丝体细胞壁有轻微损伤,细胞内液泡变大,内含物减少,线粒体数量明显增加,而淀粉粒无明显变化;随着Cd2+浓度的升高,出现细胞壁、膜断裂;线粒体减少,嵴和膜模糊或消失;淀粉粒边缘糊化。当Cd2+浓度>42mg/L时,细胞完全自溶。     

植物生长调节剂“784—1”对大豆叶肉细胞超微结构的影响

本文应用植物生长调节剂“784—1”进行大豆种子浸种和拌种处理。田间试验与电镜观察结果表明,与对照组比较,叶肉细胞中的线粒体、叶绿体和叶绿体内片层结构呈增多趋势。     

玉米线虫矮化病病原对玉米叶片超微结构的影响

利用透射电镜技术对健康和感病玉米叶片细胞超微结构进行观察,明确玉米线虫矮化病病原侵染后玉米叶片病理反应的细胞学特征。结果表明,与健康植株相比,玉米线虫矮化病病原与玉米植株之间的互作均可导致寄主发生明显的细胞病理学变化。在受侵染的玉米叶肉细胞中叶绿体膨胀变形,数量相对减少,双膜结构破损;基粒片层结构膨胀、排列无序、甚至解体;线粒体数量增多、肿胀变形、内嵴模糊不清,严重者内嵴消失并空泡化;细胞核形态变为不规则,核膜破裂;染色质分布不均匀,呈降解状态。     

Differential Sensitivity of Chloroplasts in Mesophyll and Bundle Sheath Cells in Maize,an NADP-Malic Enzyme-Type C4 Plant,to Salinity Stress

Abstract

The changes in chloroplast ultrastructure and the contents of chlorophyll, Na and K in response to salinity stress were investigated in leaves of maize, an NADP-malic enzyme-type C₄ plant species possessing dimorphic chloroplasts. The seedlings were treated with 0, 1, 2 or 3% NaCl for three or five days under a light or dark condition. In both light and dark conditions, the dry weight of salt-treated plants decreased as NaCl concentration increased. Chlorophyll and K contents of the second leaf blade decreased as NaCl concentration increased under the light condition but not under the dark condition. Na content of the second leaf blade was significantly higher at high NaCl concentrations under both light and dark conditions. However, Na content was much lower under the dark condition than light condition. Higher concentrations (2 and 3%) of NaCl significantly increased the size of plastoglobules, decreased the number and size of starch granules and altered the chloroplast ultrastructure. Under the light condition, mesophyll cell (MC) chloroplasts appeared more sensitive to the damaging effect of salinity than the bundle sheath cell (BSC) chloroplasts. MC chloroplasts became more globular in shape and showed swollen and disorganized thylakoids and reduced thickness of grana by salinity. BSC chloroplasts were less affected by salinity than MC chloroplasts. Although chloroplast size and number and size of starch granules were reduced, there was no structural distortion in the thylakoids of BSC chloroplasts. However, the thickness of grana was increased by salinity. Under the dark condition, the chloroplast structure was less affected by salinity. Though the envelope of BSC chloroplasts was occasionally damaged, the thylakoids in both MC and BSC chloroplasts were preserved under salinity stress. The present study suggests that the chloroplast damage caused by salinity is light-dependent and MC chloroplasts are more sensitive to salinity than BSC chloroplasts.     

大豆光合生理生态的研究——第14报 大豆不同类型叶细胞中叶绿体的分布及超微结构

大豆叶片棚栏细胞和海绵细胞中叶绿体数量多、体积大,基质较稠密,叶绿体基粒及片层结构较复杂。维管束鞘细胞和平脉叶肉细胞中叶绿体数目较少、体积小、基质较稀疏,叶绿体基粒及片层结构较简单。维管束薄壁细胞中叶绿体数最少、体积最小,结构最简单。叶绿体在不同细胞中的分布和结构的复杂程度与各类细胞的功能及在叶片中的解剖位置有关。     

Structural and Functional Differentiation of Bundle Sheath and Mesophyll Cells in the Lamina Joint of Rice Compared with that in the Corresponding Region of the Liguleless Genotype

Abstract

The structural and functional characterization of the blade-sheath boundary region of a rice cultivar T65 and its near-isogenic line T65lg were examined by light and electron microscopy and in situ hybridization. Starch accumulation in bundle sheath cells was compared between the lamina joint of T65 and the corresponding region of T65lg and also between the lamina joint and the leaf blade. In the lamina joint of T65, starch grains were predominantly accumulated in bundle sheath cells, and the starch-containing chloroplasts within these cells were spherical in shape. On the other hand, in the blade-sheath transition region of T65lg, little starch accumulation was observed and the chloroplasts were oval in both mesophyll and bundle sheath cells. Furthermore, photosynthesis-related genes, rbcS and cab, were expressed in mesophyll cells within the blade-sheath transition region of T65lg as in the leaf blade and sheath, while no expression of these genes was found within the lamina joint of T65. These facts indicate that T65lg can not develop the lamina joint from either structural or functional aspect. The present results suggest that the control mechanism of starch accumulation in bundle sheath chloroplasts in the lamina joint differs from that in leaf blade in rice.     

Intracellular position of mitochondria and chloroplasts in bundle sheath and mesophyll cells of C3 grasses in relation to photorespiratory CO2 loss

In C₃ plants, photosynthetic efficiency is reduced by photorespiration. A part of CO₂ fixed during photosynthesis in chloroplasts is lost from mitochondria during photorespiration by decarboxylation of glycine by glycine decarboxylase (GDC). Thus, the intracellular position of mitochondria in photosynthetic cells is critical to the rate of photorespiratory CO₂ loss. We investigated the intracellular position of mitochondria in parenchyma sheath (PS) and mesophyll cells of 10 C₃ grasses from 3 subfamilies (Ehrhartoideae, Panicoideae, and Pooideae) by immunostaining for GDC and light and electron microscopic observation. Immunostaining suggested that many mitochondria were located in the inner half of PS cells and on the vacuole side of chloroplasts in mesophyll cells. Organelle quantification showed that 62–75% of PS mitochondria were located in the inner half of cells, and 62–78% of PS chloroplasts were in the outer half. In mesophyll cells, 61–92% of mitochondria were positioned on the vacuole side of chloroplasts and stromules. In PS cells, such location would reduce the loss of photorespiratory CO₂ by lengthening the path of CO₂ diffusion and allow more efficient fixation of CO₂ from intercellular spaces. In mesophyll cells, it would facilitate scavenging by chloroplasts of photorespiratory CO₂ released from mitochondria. Our data suggest that the PS cells of C₃ grasses have already acquired an initial structure leading to proto-Kranz and further C₃–C₄ intermediate anatomy. We also found that in the Pooideae, organelle positioning in PS cells on the phloem side resembles that in mesophyll cells.     

水杨酸和赤霉素复配剂对低温下玉米光合特性的影响

将水杨酸(SA)和赤霉素(GA)进行复配,研究复配剂(SGM)对田间玉米光合特性的影响。结果表明:SGM处理提高低温胁迫下玉米的生物产量,试验中SGM3(SA0.03%+GA15 mg/L)处理的生物产量比对照高5.04%;拔节期SGM处理的玉米单株叶面积均高于对照,其中SGM3处理的叶面积较对照提高17.42%,达显著水平;SGM处理使玉米幼苗叶片在低温胁迫条件下总叶绿素含量增加,提高低温胁迫条件下玉米幼苗的光合速率;SGM处理可在低温胁迫下保护玉米幼苗叶绿体结构,保持叶绿体超微结构完整,基质片层结构清晰,基粒片层排列整齐。     

不同铁效率大豆品种叶片和根系超微结构的比较研究

采用盆栽试验方法研究了施用螯合铁肥(Fe-EDDHA)对不同铁效率大豆V4期叶片及根系超微结构的影响。结果表明:铁敏感品种缺铁处理下植株矮小且叶片发黄,而铁高效品种缺铁条件下植株稍小但叶色差异不大。两种处理下铁高效品种的叶绿素SPDA值无显著差异,铁敏感品种在缺铁条件下叶绿素SPDA值显著小于补铁条件下,也显著小于铁高效品种。铁敏感品种叶肉细胞中叶绿体和线粒体数量在两种处理下差异不大,但铁敏感品种缺铁处理下叶绿体不饱满呈长梭形且其中淀粉颗粒形状扁平,含量较少;铁高效品种在两种处理下线粒体和叶绿体数目差异不大,但总体上在补铁处理下叶肉细胞中淀粉颗粒的含量较高、颗粒较大。铁敏感品种根系细胞缺铁处理下形状不规则,细胞壁严重变形,原生质破裂外流且分布不均,细胞核及大部分细胞器有解体现象,而补铁处理下细胞结构则保持规则完整;铁高效品种在两种处理下根系细胞均规则完整,但补铁处理下原生质体浓厚且内含物较丰富。由此说明:缺铁胁迫对不同铁效率大豆品种植株大小、叶色、细胞超微结构都有影响,只是铁敏感品种受缺铁胁迫影响更大,而铁高效品种可能有较完善的耐低铁机制所以受缺铁胁迫影响较小。     

不同类型小麦品种大、小淀粉粒的分离和特性

为给小麦品质育种提供依据,以3个不同类型的小麦品种(济南17号、扬麦12号和扬麦9号)为材料,分离了大、小淀粉粒,并对它们的特性(形状、大小、膨胀势、晶体特性、糊化特性等)进行了测定和分析.结果表明,大、小淀粉粒形状为椭球形或球形,品种间无差别,但其大小和含量在品种间存在很大差异;大淀粉粒的膨胀势大于小淀粉粒.大、小淀粉粒都为A型淀粉晶体,大淀粉粒的相对结晶度差别不大,但小淀粉粒的相对结晶度差别较大,表现为济南17号＜扬麦12号＜扬麦9号.品种内大淀粉粒的起始温度To、峰值温度Tp值和吸收热焓△H高于小淀粉粒,终止温度Tc值却比小淀粉粒低.     

Effects of Exogenous Glycinebetaine on Growth and Ultrastructure of Salt-Stressed Rice Seedlings (Oryza sativa L.)

Abstract

The effects of exogenously applied glycinebetaine on the salt-stress-induced inhibition of growth and ultrastructural damages in rice seedlings were investigated. Glycinebetaine was not effective in alleviating the NaCl-induced inhibition of root growth and rather enhanced the NaCl-induced inhibition. However, it was found to alleviate the inhibition of shoot growth induced by NaCl stress. Concentrations of Na were higher in salt-stressed plants than in unstressed plants. Stressed plants receiving glycinebetaine had a significantly lower Na and higher K concentrations in the shoots than the plants grown without application of glycinebetaine. Salinity induced ultrastructural damages in leaf such as swelling of thylakoids, disintegration of grana stacking and intergranal lamellae and destruction of mitochondria (deficiency of cristae, swelling and vacuolation). Such damages were largely prevented by pretreatment with glycinebetaine resulting in greening of the plants. In roots, the epidermis, cortex and root cap were more sensitive to salt stress than the meristem and stele. The most frequently observed ultrastructural alteration due to NaCl salinity was the formation of many large vacuoles in the root tip and root cap cells. The number of mitochondria was increased and they were aggregated in the cytoplasm of the root tip and root cap cells by treatment with NaCl or NaCl plus glycinebetaine. Glycinebetaine could not prevent the NaCl-induced ultrastructural damages in root cells. The effects of glycinebetaine to mitigate the ultrastructural damages in the chloroplast and mitochondria induced by NaCl might be due to the production of many vacuoles in root cells which may act to store Na and decrease its accumulation in the shoot.     

干旱胁迫对燕麦叶片气孔和叶肉细胞超微结构的影响

为了解干旱后燕麦解剖结构的变化,以燕麦品种白燕2号为材料,通过盆栽控水试验,设置正常供水、轻度干旱和重度干旱三个不同水分处理(土壤含水量分别为田间持水量的75%、60%和45%),研究了干旱胁迫对燕麦叶片渗透调节物质含量、气孔和叶肉细胞超微结构的影响。结果表明,正常水分条件(对照)下,燕麦叶片脯氨酸和可溶性糖含量较低,表皮细胞皱褶,气孔关闭或微张,叶肉细胞内细胞器形状规则,结构清晰。与对照相比,轻度干旱胁迫下,燕麦叶片脯氨酸和可溶性糖含量增加,叶片表皮细胞饱满,气孔开启度较大,叶绿体形状变圆,近球状,线粒体外被膜膨胀,但结构未见明显损伤;重度干旱胁迫下,叶片脯氨酸和可溶性糖含量极显著增加,表皮细胞干瘪,气孔保卫细胞膨胀,气孔关闭,气孔器下陷。重度干旱胁迫下,燕麦叶绿体和线粒体受到的损伤较大,叶绿体内基粒、基质类囊体降解,出现较大的空腔;线粒体外被膜断裂,内含物流失;细胞核染色质凝聚,叶绿体之间出现嵌合现象。因此,干旱胁迫能诱导燕麦叶片渗透调节物质的积累和细胞超微结构的改变,渗透调节物质增幅和细胞超微结构的破坏程度随着土壤有效水分含量的降低而上升,但在细胞超微结构上也出现抗性反应,表明燕麦具有较强的抗旱性。