几种植物细胞表面糖蛋白的电镜细胞化学及其与植物抗逆性的关系

1.无论是小麦、玉米或长豇豆的叶片组织,经钌红染色显示的糖蛋白均明显地定位于细胞间隙周围游离的细胞表面上,在细胞壁的外部形成一个糖蛋白层,厚度一般为50—100nm之间。紧贴细胞壁的部分比较致密,外部边缘比较松散,有些呈现为丝状。2.抗寒性强的冬小麦幼苗叶片细胞表面的糖蛋白比不抗寒的春小麦品种显得丰富;并且在低温锻炼中,前者细胞表面的糖蛋白层有增厚的趋势,而后者的糖蛋白层明显变薄、甚至完全消失。3.当长豇豆叶片感染花叶病或玉米叶片感染小斑病后,黄色病斑组织的细胞表面的糖蛋白向细胞间隙中脱落,直至糖蛋白层完全消失。病斑周围的绿色组织细胞表面的糖蛋白层,有些也发生减少,甚至完全消失;有些则增厚。抗小斑病的玉米品种的细胞表面的糖蛋白比不抗品种显得丰富。以上情况表明,细胞表面的糖蛋白与植物的抗病性和抗寒性存在密切关系。     

抗寒锻炼中不同抗寒性小麦细胞膜糖蛋白的细胞化学研究

本研究根据植物细胞的特点,修改了在动物和人体细胞方面立的酶标Con A的电镜细胞化学方法,成功地展现了2个不同抗寒性冬小麦品种幼苗在抗寒锻炼和脱锻炼过程中细胞膜系统上糖蛋白的分布动态,显示与Con A连接的标志酶-辣根过氧化物酶活性的反应产物呈颗粒状分散分布在质膜、内质网、核膜及液泡膜的一些部位上,揭示糖蛋白在冬小麦细胞膜系统上的分布似有其特定的位点。经抗寒锻炼后,强抗寒性品种燕大1817细胞内的糖蛋白在内质网和核膜上的分布量明显地增加;同时,几乎所有的胞间连丝通道中都有糖蛋白的分布。脱锻炼后,内质网和核膜上的糖蛋白分布量又减少,胞间连丝通道中的糖蛋白也消失,基本上回复到抗寒锻炼前的分布状态。抗寒性弱的冬小麦品种郑州39-1幼苗在同样的抗寒锻炼和脱锻炼过程中不产生这些明显的变化。这些结果说明,抗寒锻炼中内质网和核膜上糖蛋白分布量的增加,以及糖蛋白输入胞间连丝的动态变化是与植物抗寒力的提高和保持稳定密切相关的。     

细胞壁羟脯氨酸和游离脯氨酸与棉花对枯萎病抗性的关系

氟乐灵处理能推迟棉苗枯萎病症状的出现、降低发病株率和病情指数,说明氟乐灵处理能提高棉酋对枯萎病的抗性。在健康棉苗中,抗病品种（中棉１２）细胞壁结合的羟脯氨酸含量显著高于感病品种（６０３７）,但游离脯氨酸含量无明显差异。在氟乐灵处理和未处理而接种棉枯萎病菌的两个处理中,两个品种的细胞壁结合的羟脯氨酸和游离脯氨酸含量均高于各自的健康株对照,而且抗病品种中的含量都高于感病品种,说明细胞壁结合的羟脯氨酸和游禹脯氨酸的积累是氟乐灵诱发的抗病性表现及棉苗受枯萎病菌侵染后抗性反应的生化机制之一。     

不同品种小麦叶片对拔节期低温的生理响应及抗寒性评价

以黄淮海麦区参加区试的24个小麦品种为材料,分析了拔节期低温胁迫对其叶片相对电导率、可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)和过氧化物酶(POD)活性的影响。结果表明,低温胁迫后,叶片相对电导率、可溶性糖含量、脯氨酸含量、MDA含量、SOD活性和POD活性均高于对照(P0.01),而可溶性蛋白含量低于对照(P0.01)。小麦叶片各指标存在极显著的品种间差异(P0.01)。以叶片各指标的相对值作为抗寒性指标,采用隶属函数法和极极点排序法计算参试品种的平均隶属度值为0.19—0.63,综合排序值为1.66—4.08。通过K-means聚类,将24个小麦品种聚为5类。其中良星619、丰德存麦1号、B07-4056、石H083-363、山农055843和良星99等6个品种抗寒性最强,宿553、陕农509、A-9、中原6号、徐麦4036、舜麦1718和石麦19等7个品种抗寒性强,尧麦16、C-44、山农05-066、冀麦585和石B05-7388等5个品种抗寒性中等,偃展4110、B-33、B05-6507和石4185等4个品种抗寒性弱,石06-6136和石优20这2个品种抗寒性最弱。相关分析表明,平均隶属度值和综合排序值与相对可溶性糖含量、相对脯氨酸含量、相对POD活性呈正相关(P0.05),与相对MDA含量呈负相关(P0.05)。叶片可溶性糖含量、游离脯氨酸含量、POD活性及MDA含量可以作为拔节期小麦抗寒性的鉴定评价指标。     

柴胡幼苗越冬抗寒性及其相关生理指标筛选

以北柴胡、地产柴胡、三岛柴胡的根为试验材料,以早春植株成活率为越冬抗寒性指标,测定越冬期不同柴胡品种根系生理生化特征,进行柴胡抗寒性综合评价,并对主要抗寒生理指标进行通径分析和相关性分析,以探讨冬季自然低温条件下柴胡生理特性与抗寒性的关系,筛选适合柴胡越冬抗寒性鉴定的生理指标。结果表明:(1)北柴胡、地产柴胡、三岛柴胡返青期的返青率依次为80%、50%、10%,且各品种间差异显著。(2)3个品种柴胡越冬期根系可溶性糖含量、游离脯氨酸含量、可溶性蛋白含量、根系活力与返青率大小顺序一致,其中北柴胡根系游离脯氨酸平均含量分别为地产柴胡和三岛柴胡的2.44倍和4.49倍,且可溶性蛋白含量显著高于地产柴胡、三岛柴胡,但3个品种柴胡的相对电导率、丙二醛含量水平与返青率大小顺序相反。(3)自然越冬过程中,各柴胡品种的根系活力均呈下降趋势,且以三岛柴胡根系活力下降幅度最大,达80%,而北柴胡根系活力下降幅度最小为52.04%。(4)越冬期3个柴胡品种的越冬抗寒性综合排序为:北柴胡地产柴胡三岛柴胡;柴胡根中脯氨酸含量、可溶性蛋白含量与综合评价值呈极显著正相关关系,相对电导率与综合评价值呈显著负相关关系;生理指标决策系数的大小顺序依次为脯氨酸含量可溶性蛋白含量电导率。研究表明,越冬期柴胡根系游离脯氨酸含量是影响其抗寒性的主要影响因素,其含量可作为评价柴胡抗寒性的指标。     

低温处理下不同禾本科牧草的生理变化及其抗寒性比较

研究牧草根系抗寒性的动态变化,对寒冷地区的牧草引种筛选意义重大.试验以美国引进的禾本科牧草高山早熟禾(Poa Aalpine)、俄罗斯野麦(Elymus junceus)、无芒冰草(Agropyron inerme)、爱达荷冰草(Agropyron inerme)(品种名Secar)和爱达荷冰草(Agropyron inerme)(品种名Goldar)为研究材料,人工控温进行低温抗寒锻炼、冷冻处理和解冻恢复生长,测定每一阶段下根系中MDA、可溶性蛋白质、可溶性糖和脯氨酸的含量及SOD活性.结果表明,MDA含量在抗寒锻炼后略有增加,随后维持基本稳定;SOD活性在抗寒锻炼后升高,冷冻处理后显著降低;返青后又显著升高(P＜0.05);可溶性蛋白质、可溶性糖和脯氨酸含量在抗寒锻炼和冷冻处理后升高,返青后降低;其中,SOD活性、可溶性糖和脯氨酸的含量随处理不同变幅较大,MDA和可溶性蛋白质的含量随处理不同变幅较小.运用Fuzzy数学中隶属函数法进行抗寒性综合评判,得出抗寒性强弱顺序为:高山早熟禾＞俄罗斯野麦＞爱达荷冰草(Secar)＞无芒冰草＞爱达荷冰草(Goldar).     

低温锻炼对小麦类囊体膜脂膜蛋白的影响

比较两种不同抗寒性小麦品种在低温锻炼前后类囊体膜脂及其脂肪酸成分、光系统Ⅱ捕光叶绿素ａ／ｂ 蛋白复合体（ＬＨＣⅡ）及类囊体吸收光谱,低温荧光发射光谱,发现经低温锻炼后：（１）抗寒与不抗寒品种小麦类囊体磷脂酰甘油（ＰＧ）的反式十六碳－烯酸含量均明显降低;抗寒品种小麦的单半乳糖基甘油二酯（ＭＧＤＧ）／双半乳糖基甘油二酯（ＤＧＤＧ）比值明显降低,而不抗寒品种变化不明显。（２）抗寒品种小麦类脂／叶绿素比值明显增高。（３）两品种小麦类囊体膜ＬＨＣⅡ寡聚体含量均降低,而单体含量均增加。（４）两品种小麦类囊体膜吸收四阶导数光谱Ａ６８３／Ａ６５２比值均升高。（５）不抗寒品种小麦低温荧光发射光谱Ｆ６８５／Ｆ７３８比值上升,而抗寒品种没有变化。我们认为,在低温锻炼过程中膜流动性增大可能是植物抗寒性增强的重要原因,此外,ＭＧＤＧ 含量降低对低温下膜双层的稳定性可能起重要作用     

脯氨酸含量在作物低温锻炼中的变化及同抗寒性的关系

本文对抗寒能力不同的冬小麦、春小麦、莜麦及谷子的幼苗,在1,300勒克斯光强下,经12℃、5℃及-5℃的低温锻炼后,观测其幼苗中的脯氨酸变化与抗寒性之间的关系。在正常温度(25℃)及2,500勒克斯光强下,脯氨酸含量的差异与上述作物幼苗的抗寒力无相关性。在1,300勒克斯光强下,经12℃低温锻炼三天后,供试作物的脯氨酸含量均比在正常温度下生长的幼苗有提高,其增长的幅度与作物幼苗抗寒能力完全一致。抗寒最强的冬小麦增长近六倍,其次是春小麦,增加了三倍,而抗寒力差的莜麦和谷子则只增加50—75％。供试作物在12℃、5℃及-5℃温度下的脯氨酸含量均比在正常温度时的高,我们认为在12℃及5℃的增加是作物对低温的一种适应性反应,而-5℃时的增长则可能是受害的标志,是蛋白质降解的结果。脯氨酸积累的高峰在12℃时是第七天。本文对脯氨酸积累的阈温及对光的依赖性问题也进行了讨论。     

羊草抗羟脯氨酸细胞变异系的筛选及其特性分析

离体培养条件下 ,用脯氨酸类似物羟脯氨酸 ( HYP) 2 0 mmol/L作选择压力 ,筛选出羊草( Aneurolepidium chinense( Trin.) Kitag.)抗 HYP细胞变异系 HR2 0 - 8。其游离脯氨酸含量比供体提高 6.6倍 ,而且抗 Na Cl、PEG及低温的能力也较供体增强。对变异系脯氨酸合成途径进行分析 ,发现其中控制第一步反应的关键酶—— -谷氨酸激酶的活性异常增加 ,比供体高 2 .5倍。而且外源脯氨酸对变异系和供体的 -谷氨酸激酶的抑制表现得很相似。     

火龙果幼苗对低温胁迫的生理响应及其抗寒性综合评价

以野生火龙果量天尺和贵州主栽品种‘紫红龙’、‘晶红龙’、‘粉红龙’扦插幼苗为试材,人工控温进行抗寒锻炼、低温冷害处理及恢复生长,以未处理作对照,测定不同处理下幼苗的电解质渗出率(REC)、可溶性糖、可溶性蛋白、游离脯氨酸和丙二醛(MDA)含量的变化。结果表明,电解质渗出率随温度降低逐渐增加,恢复生长后电解质渗出率与对照之间没有显著差别。幼苗中的可溶性糖、可溶性蛋白、脯氨酸及丙二醛含量在抗寒锻炼和低温处理后升高,恢复生长后降低。可溶性糖和脯氨酸含量随不同处理变幅较大,MDA和可溶性蛋白随不同处理变幅较小。运用Fuzzy数学中隶属函数法进行抗寒性综合评价,得出火龙果抗寒性强弱表现为量天尺>‘晶红龙’>‘粉红龙’>‘紫红龙’,与恢复生长的试验结果基本一致。     

Cytological Studies on the Cold Resistance of Plants the Changes of the Intracellular Materials of Wheat in the Overwintering Period

In the literature, the information on the correlation between the material changes and the cold resistance of plants is full of contraditions, especially in regard to the changes of the sugar and protein contents in connection with the development of the cold resistance in hardened condition. The present work was undertaken with an attempt to study the changes of the intracellular materials of wheat in the overwintering period with cytochemical methods. The wheat varieties used in this study were the same as used in our previous work (Chien and Wu, 1965), these are, 2 winter varieties (Nungta 183 and Huapei 187), 2 spring varieties (Nanta 2419 and Piyü), and 2 intermediate ones (Pima No. 1 and Pingyaian 50). The plants of the different varieties were cultivated under the same environmental conditions. Samples were collected and fixed at the same time (twice a month from October to March). For making microscopical preparations, the sections of materials for comparative studies were mounted on the same slide, so that they all were subjected to exactly the same treatment. The results obtained are summarized as follows: 1. The starch content in the cells of the tillering nodes increased, as the temperature fell in autumn. The starch grains gradually disintegrated when the plants came in hardened period (late October to mid-November), and completely disappeared in severe winter (January). They were regenerated in mid-February. 2. The soluble sugar gradually increased with the falling of the temperature in late autumn and steadily increased until the temperature approached 0 ℃. However, when the temperature dropped further, the soluble sugar content decreased and finally in March reached the level which it assumed before winter. 3. It was determined by cytochemical reactions that the cytoplasmic proteins and RNA and the nuclear basic proteins increased from late autumn to early winter. The degree of these changes showed apparent difference between the different varieties. Based on the phenomena observed, the authors discussed their correlation with the cold resistance of wheat plants. 4. The fat and lipids were also tested, but there was no indication of the occurrence of these substances in the winter season. The study on the DNA content revealed no correlation of any kind with the development of the wheat hardiness.     

干旱胁迫下小麦叶片的电阻抗图谱参数与生理参数的关系

通过盆栽实验,在适宜水分、中度干旱和严重干旱水分条件下,分别测定了3个不同抗旱类型的7个小麦品种叶片的电阻和电抗以及保护酶活性、MDA含量、细胞膜相对透性、脯氨酸和含水量等生理参数,并拟合了胞外电阻、胞内电阻、驰豫时间以及驰豫时间的分布系数等电阻抗图谱参数,分析了叶片的电阻抗图谱参数与生理参数之间的相关性。结果表明,在受到水分胁迫后,小麦叶片的CAT、POD活性较适宜水分条件下降低,MDA含量、细胞膜相对透性和脯氨酸含量增加,含水量减小;胞外电阻、胞内电阻、驰豫时间以及驰豫时间的分布系数在品种间差异均极显著(P<0.01),而仅胞内电阻在水分处理间差异显著(P<0.05);在适宜水分条件下,胞外电阻与细胞膜透性有显著负相关,驰豫时间与丙二醛、含水量之间有显著正相关,而在严重干旱条件下,驰豫时间分布系数与丙二醛含量之间有显著正相关,胞内电阻与含水量之间有显著负相关。可见,胞内电阻和驰豫时间分布系数在一定程度上反映了小麦叶片受水分胁迫的程度。     

Stability of wheat Protoplasts during Freezing-Thawing in Relation to Cold Resistance of Its Varieties

Freezing tolerance of isolated protoplasts of three wheat, varieties which differ from each other in cold resistance has been measured. The results obtained in the present study indicate that the survival percentage of wheat protoplasts after freezing treatment is indirect correlation with the cold resistance of its varieties. It is discussed that the change in plasmolemma plays a role in the mechanism of chilling injury and cold resistance of plants, and the results obtained may be used as an indicator for determining the cold resistance of the plants.     

Cold acclimation of wheat (Triticum aestivum): Properties of enzymes involved in proline metabolism

Two cultivars of wheat ( Triticum aestivum L.), a winter wheat, Kharkov, and a spring wheat, Glenlea, were acclimated under controlled conditions at 2 temperatures, 5°C and 25°C with a 12-h photoperiod. Water content, protein and proline concentrations were determined. Enzymatic properties (activity and apparent energy of activation) were investigated for enzymatic systems involved in 2 pathways of proline metabolism, the glutamic acid and ornithine pathways. Four enzymes were studied, proline dehydrogenase (PDH, EC 1.5.1.2), glutamate dehydrogenase (GDH, EC 1.4.1.2-4), glutamine synthetase (GS, EC 6.3.1.2) and ornithine transaminase (OT, EC 2.6.1.13). Cold acclimation led to an accumulation of proline, a decrease in water content and an increase in soluble protein, especially in winter wheat. For both cultivars, cold acclimation modulated enzyme properties of PDH and GDH. Increased activities of GS and OT were observed as a result of cold acclimation in both cultivars, with the greatest increase in Kharkov. The apparent energy of activation of these 2 enzymes decreased, particularly for Kharkov, which accumulated proline in cold conditions.     

Rice callus growth, proline content and activity of proline and IAA oxidase under the influence of hydroxyproline and NaCl

Calli of salt tolerant (Bhoora rata) and salt susceptible (GR₁₁) rice varieties were cultured on Linsmaeir and Skoog’s medium containing LD₅₀ concentration of NaCl (200 mM) and hydroxyproline (10 mM). Growth, proline content and activity of proline and IAA oxidases of the cultured tissues were determined at the end of 0, 2, 4, and 6 weeks of incubation. Hydroxyproline resistant calli of both rice varieties when cultured on Linsmaeir and Skoog’s medium containing hydroxyproline and NaCl showed increased dry weight and proline content as compared to NaCl stressed calli. The levels of proline and IAA oxidases were also low in the hydroxyproline resistant calli.     

Hardening, abscisic acid, proline and freezing resistance in two winter wheat varieties

Two varieties of winter wheat ( Triticum aestivum L.) differing in freezing resistance ("Holme" from Sweden, freezing resistant, and "Amandus" from Germany, less freezing resistant) were hardened for five weeks by gradually reducing the day/night temperature from 20°C/15°C during the first week to 2° C/0° C during the fifth week and the photoperiod from 15 to 9 h. This treatment increased the freezing resistance of both varieties in comparison to unhardened control plants. Hardening caused an increase in osmolarity of cell sap and in the levels of proline and abscisic acid (ABA). Increase in osmolarity preceded the increase in ABA level, and proline levels increased later than ABA levels. Holme had higher values of osmolarity as well as higher levels of ABA and proline. but the differences between the two varieties were significant only for proline. Since the pressure potential remained constant or increased slightly during the hardening period, it is suggested that the accumulation of ABA is due to the hardening process and not to simple water stress caused by cold-induced inhibition of water uptake by the root.
Spraying hardened plants with 10⁻⁴ M ABA 24 h before a freezing test increased freezing resistance in both varieties, but did not obliterate the differences in freezing resistance between the two varieties. Spraying hardened plants with an aqueous proline solution (10%, w/v) was without effect on freezing resistance. It is concluded that the hardening procedure causes an accumulation of ABA in winter wheat leaves and that ABA is involved in the chain of events leading to freezing resistance.     

越冬过程中花椒抗寒性与组织水和渗透调节物质的变化

花椒越冬过程中的抗寒性经历了弱抗寒性时期（11月初以前的时期）、抗寒性增强期（11月初至翌年1月初）、抗寒性最强期（翌年1月份）和抗寒性减弱期（翌年2月初以后）等4个时期。花椒的束缚水与自由水比值、可溶性糖和可溶性蛋白的含量与抗寒性显著相关,而脯胺酸含量与抗寒性相关性不显著。花椒可通过增加束缚水与自由水之间比值、可溶性糖和可溶性蛋白的含量来提高抗寒性,以适应低温环境。