EFFECTS OF VARIOUS FACTORS ON THE INCREASE OF {alpha}-AMYLASE ACTIVITY IN RICE ENDOSPERM INDUCED BY GIBBERELLIN A3

The increase of -amylase activity in embryoless rice endosperminduced by the addition of gibberellin A₃ was examined undervarious conditions with an aim to establish a bioassay methodfor gibberellins. Sterilized embryoless rice endosperms were incubated in a testtube containing 0.2–1.0 ml of test solution for 4 daysat 30. -Amylase activity in the endosperm was determined bymeasuring digestion of added starch. The increase of amylaseactivity during the incubation was not affected by the additionof various vitamins, amino acids, organic acids, protease, sucrose,indoleacetic acid or kinetin. Helminthosporol, helminthosporicacid and sclerin (1–10 µg/ml) had weak promotingeffects. Under appropriate conditions, 10^–5 µg/mlof gibberellin A₃ could be detected. In double logarithmic plot,the increase in the enzyme activity was proportional to thegibberellin A₃ concentration in the range from 10^–5 to10^–2 µg/ml. (Received April 13, 1966; )     

HORMONAL REGULATION ON THE INDUCTION OF {alpha}-AMYLASE ISOZYMES IN THE EMBRYO-LESS ENDOSPERM OF BARLEY

The -amylase induced by helminthosporol and gibberellic acidin the embryo-less endosperm of barley was separated into thethree fractions, 1, 2 and 3, by DEAE-cellulose column chromatography.A maximum amount of the 2. was induced by gibberellic acid andthat of the as by helminthosporol. After rechromatography, the2 induced by gibberellic acid and the as induced by helminthosporolshowed their respective single bands in an electrophoresis agargel zymogram. On the other hand, the ai induced by helminthosporoland gibberellic acid showed three bands. Dihydrohelminthosporic acid, a derivative of helminthosporol,induced the same isozymes as helminthosporol did. (Received May 8, 1967; )     

胚乳对幼苗中苯丙氨酸解氨酶(PAL)活性的影响

在小麦、大麦、玉米黄化幼苗的萌发过程中,PAL活性有“消长”现象。当去胚乳后,幼苗中PAL活性普遍下降。亚胺环己酮处理可以阻止去胚乳造成的PAL活性下降。大麦、小麦去胚乳老化12h幼苗的提取液可在体外抑制整体苗的PAL活性。表明胚乳在调节幼苗体内PAL活性方面具有一定的作用。去胚乳后体内有PAL“抑制蛋白”的积累。     

外源胆固醇对水稻根端线粒体ATP酶活力的影响

外源胆固醇无论是通过根系吸收或是直接与离体线粒体一起温育的方式,在试验浓度范围内均能提高水稻根端线粒体ATP酶的活力,同时观察到外源胆固醇能明显降低ATP酶表现活化能(Apparent activation energy,AEa)在Arrhenius图上的折点温度。其中通过根系吸收进入线粒体膜内后,其线粒体ATP酶AEa的两个折点温度由对照的27.7℃和15.5℃分别降低到24.5℃和12.7℃;直接与离体线粒体一起温育的两个折点温度分别降低到18.8℃和9.6℃。试验结果证明,适量的外源胆固醇不仅对水稻根端线粒体ATP酶活力具有明显的促进作用,而且对降低线粒体膜脂的相变温度也有明显的调节作用。     

硫和6-苄氨基腺嘌呤对水稻幼苗硝酸还原酶活性的影响

缺硫培养6天的水稻幼苗,其叶片和根中的硝酸还原酶(NR)活性明显下降。用1pPm 的6-苄氨基腺嘌呤(6-BA)处理培养了10天的水稻幼苗根系,24小时后缺硫培养的水稻幼苗叶片和根系的 NR 活性升高,加硫培养的水稻幼苗叶片和根中的 NR 活性下降。用~(35)S示踪发现,6-BA 可降低加硫幼苗对~(35)S 的吸收和转化,但促进缺硫幼苗对~(35)S 的转化。     

扑虱灵对稻飞虱及其捕食性天敌种群的影响

扑虱灵对稻飞虱的防治效果,及对捕食性天敌的毒性,进行了田间试验,并与叶蝉散,杀虫双的使用结果作比较．试验结果表明,扑虱灵对稻飞虱的防治效果达93％,与叶蝉散,杀虫双相比较。防治效果提高了2．39～32．85％．对黑肩绿盲蝽和蜘蛛种群具有不同程度的选择性,维护较低的稻飞虱与天敌的比值,有利于天敌作用的发挥,维持对稻飞虱较长的残效期,基本上可以控制稻田后期飞虱的增长．     

楝科植物油及种核粉抽提物对稻瘿蚊产卵忌避作用及防治试验

稻瘿蚊Orseolia oryzae发生世代亟叠,复杂,为害严重,是我国华南地区及东南亚水稻产区的重要害虫。近几年来,我们应用楝科等杀虫植物进行了防治试验,本文主要报道楝科种子油及其抽提物引起产卵稻瘿蚊忌避反应及防治效果。     

水稻胚乳发育中淀粉体和蛋白体ATPase活性的动态变化

利用ATPase定位技术,对水稻品种(OryzasativaL.cv.Minghui63)胚乳细胞发育中后期淀粉体和蛋白体的ATPase活性进行了超微细胞化学定位。结果表明,在淀粉体内外膜上、淀粉粒间的通道上和淀粉体四周的无定形物上呈现显著的ATPase活性。蛋白体Ⅰ和蛋白体Ⅱ的膜上和四周的囊泡、小泡上均出现ATPase活性产物。另外,胚乳细胞的胞壁和质膜,糊粉层和亚糊粉层细胞的胞壁、质膜、细胞核和胞间连丝上也有定位的ATPase活性产物分布。根据ATPase活性产物分布特点,推测淀粉体内的网状通道是便于养分进入淀粉体内部的转运通道。淀粉体膜和蛋白体膜上的ATPase主要是为养分进入内部提供跨膜动力。     

THE EFFECTS OF SOME NEWER ANAESTHETICS ON THE IN VITRO ACTIVITY OF GLUTAMATE DECARBOXYLASE AND GABA TRANSAMINASE IN CRUDE BRAIN EXTRACTS AND ON THE LEVELS OF AMINO ACIDS IN VIVO

—The effects of several anaesthetic and hypnotic compounds with well-defined excitatory side-effects on glutamate decarboxylase and γ-aminobutyric acid transaminase activity have been examined. The dissociative anaesthetics ketamine and γ-hydroxybutyric acid produced competitive inhibition of glutamate decarboxylase with respect to glutamate at concentrations which had no effect on GABA transaminase activity. The inhibitor constant (K_i) values were, ketamine: 13.3 mm , γ-hydroxybutyric acid; 8.8 mm . The steroid anaesthetic alphaxalone was also a potent competitive inhibitor of glutamate decarboxylase K_i= 4.1 mm ). Pentobarbitone, thiopentone and methohexitone non-competitively inhibited both glutamate decarboxylase and GABA-transaminase but only at high concentration (> 20 mm ). None of the drugs tested produced any significant change in brain GABA or glutamate levels following the injection of an hypnotic or anaesthetic dose. It is proposed that an alteration in the rate of GABA synthesis as a result of the inhibition of glutamate decarboxylase could explain the convulsive properties of the dissociative anaesthetics when given at high doses.     

硫对水稻幼苗乙烯产生的影响

水稻幼苗缺硫培养12—15天,叶和根中的乙烯产生量明显降低,缺硫培养时间延长,根的乙烯产生量继续降低,叶的乙烯产生量升高。在缺硫幼苗中供给 SO_4~(2-)和0.1mmol/l 的半胱氨酸,乙烯产生量分别在36和12小时后升高到加硫幼苗的水平。供给0.1mmol/l 蛋氨酸,6小时后的乙烯产生量已高于加硫的幼苗。测定培养13天的幼苗叶片中游离氨基酸表明,缺硫幼苗其蛋氨酸和胱氨酸的含量降低。     

THE EFFECT OF PLANT EXTRACTS ON THE GERMINATION OF THE CONIDIA OF VENTURIA INAEQUALIS

Of 1915 flowering plants 23 % gave extracts which completely inhibited the germination of the conidia of Venturia inaequalis under the experimental conditions used. The plants which gave active extracts are distributed throughout the Angiosperms, and there is no correlation with systematic position. The inhibitors were distributed generally in some plants and were localized in others, e.g. to the leaves.
Some extracts appeared merely to inhibit the germination of the conidia while others killed them.
Some inhibitors disappeared when the plants were dried, other dry material was still active when retested several months later.
Hedera Helix contains an inhibitor which is active when the extract is diluted 128 times.     

猫爪草提取物体外抗肿瘤作用的研究

为探讨猫爪草不同提取物对体外培养的肿瘤细胞的作用,采用系统溶剂法提取猫爪草皂苷及多糖,运用MTT和集落形成实验法观察不同浓度的皂苷及多糖对体外培养的肉瘤S180、艾氏腹水瘤EAC及人乳腺癌细胞株MCF-7的影响。结果发现猫爪草皂苷及多糖对三种肿瘤细胞株的生长和集落形成均有不同程度的影响,皂苷给药量与抑瘤率和集落形成明显地呈正相关关系,而多糖有一最佳浓度。     

INHIBITION OF THE PHOTOSYNTHETIC CARBON DIOXIDE FIXATION OF GREEN PLANTS BY {alpha}-HYDROXYSULFONATES, AND ITS EFFECTS ON THE ASSIMILATION PRODUCTS

1. Several kinds of a-hydroxysulfonates, the bisulfite additioncompounds of aldehydes and ketones, were found to inhibit thephotosynthetic carbon dioxide fixation of the barley and wheatseedlings, tobacco leaf and Chlorella cells. Bisulfite additioncompounds of glyoxal, glyoxylate and benzaldehyde were moreeffective in this respect than those of formaldehyde and acetaldehyde.
2. The presence of -hydroxysulfonate causes an increase in ratiosof :¹⁴CO₂ incorporated in glycolate and alanine, and a decreasein incorporation in serine, malate, isocitrate and citrate.It was inferred that these changes are caused by the blockingof the formation of glyoxylate through inhibition of glycolicacid oxidase by the poison.
3. A reaction scheme was proposedto account for the above-statedresults, and the bearing ofthese findings on the possible roleof glycolic acid oxidasein the photosynthetic carbon dioxidefixation and in the formationof amino and organic acids wasdiscussed.

(Received December 8, 1961; )     

寄主植物对棉蚜羧酸酯酶活性的影响

不同棉花品种对棉蚜Aphis gossypii Glov.羧酸酯酶活性具有明显的影响,在试验的7个棉花品种中,取食中棉12叶片的棉蚜α-乙酸萘酯(α-NA)羧酸酯酶活性最高(2.47微摩尔/毫克蛋白质分钟),是取食泾阳鸡脚棉种群的5.74倍.β-乙酸萘酯(β-NA)羧酸酯酶的活性以取食方渑双无的棉蚜最高(3.41微摩尔/毫克蛋白质分钟),是取食BR-S-10棉蚜的4.49倍.在取食方渑双无叶片的棉蚜中,羧酸酯酶活性大于2.5(微摩尔/毫克蛋白质分钟)的个体占28.3%(α-NA)和67.1%(β-NA),而在取食BR-S-10的种群中仅占2.6%(α-NA)和1.3%(β-NA).取食中棉12的棉蚜对β-NA与α-NA活性的比值为0.79,而取食其它棉花品种的种群β-NA与α-NA活性比值均大于1.用中棉12饲养的棉蚜对α-NA和β-NA活性均低于种群平均值的个体(CE1型)占26%;均高于平均值的个体(CE2型)占19%;对α-NA活性高于平均值,对β-NA活性低于平均值的个体(CE3型)占31%;对α-NA活性低于平均值,对β-NA活性高于平均值的个体(CE4型)占24%.取食其它6个棉花品种的棉蚜中,CE1和CE2型的比例分别为49.4—64.0%和23.4—47.2%,明显高于取食中棉12的种群,而CE3和CE4型个体仅占0—7.6%和3.4—10.4%,明显低于取食中棉12的种群.说明寄主植物对棉蚜羧酸酯酶的量和质均有影响.     

红光,远红光和植物激素对水稻幼苗生长及CAT,POX活性的影响

红光(R)和远红光(Fr)都抑制水稻胚芽的生长,但对胚芽鞘来说,红光抑制其生长,远红光表现出部分逆转效应。一定浓度单一生长素(IAA)促进水稻胚芽鞘的生长,而赤霉素(GA_3)与生长素作用相反。对于水稻的过氧化氢酶(CAT)、过氧化物酶(POX),红光促进两种酶的活性,远红光则表现出逆转效应。单一10~(-2)ppmIAA、10~(-2)ppmGA_3都促进其活性。照光时,在10~(-2)ppm IAA存在的条件下,红光表现为促进,远红光则表现为抑制;但在10~(-2)ppm GA_3存在的条件下,红光反而对两种酶的活性有抑制作用,远红光则表现为促进作用。     

脱落酸对离体水稻叶片衰老及其纤维素酶活力的影响

在脱落酸(ABA)促进离体水稻叶片衰老过程中,叶绿素含量日渐下降,纤维素酶活力日益升高。ABA 作用的滞后期为48小时。衰老叶片的胞壁附有大量的纤维素酶。酶从胞内分泌到胞壁,是与质膜结构受到损害,使透性增大有关。6-苄氨基嘌呤(6-BA)与 ABA 的相互作用对纤维素酶活力的影响表明,ABA 引起的水稻叶片衰老可分为两个阶段:在0到1天,6-BA近乎完全逆转 ABA 的效应,第二天有所减弱,这是可逆期;从第三天起,6-BA 对 ABA 几无拮抗作用,为不可逆期开始。     

水体酚类化合物污染对水稻幼苗生长的影响

用０、５０、１００和１５０×１０－６浓度的苯酚溶液处理水稻幼苗,本实验的目的是探讨苯酚对水稻幼苗生长的影响。实验结果如下：苯酚抑制水稻幼苗生长,且随着浓度的增加,其抑制作用越明显。１５０ｐｐｍ是抑制作用最强的浓度。经苯酚处理后的水稻幼苗,其根和茎的生长都抑制了,而鲜重、干重、水分含量和叶绿素含量则明显减少,硝酸还原酶和过氧化物酶活性也下降了。