The Translocation of Antibiotics in Higher Plants: I. ISOLATION OF GRISEOFULVIN AND CHLORAMPHENICOL FROM PLANT TISSUE

Griseofulvin and chloramphenicol have been recovered from thetissues of broad-bean plants grown in solutions containing theseantibiotics. Partial separation of the compounds from other constituentsof solvent extracts of plant tissue was effected by counter-currentdistribution in a carbon tetra chloride methanol : water system.Pure griseofulvin and chloramphenicol were then obtained byrecovery of the solute in appropriate tubes followed by chromatographyon an activated alumina column; they were identified by mixedmelting point determinations and comparison of their infra-redspectra. A method for estimating griseofulvin in plant tissue extractsbased on counter current distribution and examination of thefractions spectrophotometrically has been developed, and usedto strike a balance between the gnseofulvin entering the plantand that present in the tissues after treatment. Estimates of chloramphenicol in the tissues by bioassay agreewell with the chemical determinations.     

The Translocation of Sulphonamides in Higher Plants: III. ACETYLATION AND DEACETYLATION OF SULPHANILAMIDE IN BROAD BEANS AND WHEAT

The acetylation of both amino groups on sulphanilaniide hasbeen demon strated by paper chromatography of sap expressedfrom broad beans treated with suiphanilamide through the roots.Deacetylation of N¹- and N⁴ mides occurred in the leaves oftreated plants and the N⁴ compound was also acetylated to yieldthe N¹: N⁴-diacetylsulphanilamide. About 30 per cent. of the suiphanilamide entering broad-beanroots was acetylated in the roots, the maximum proportion ofthe N⁴-acetyl compound being reached after 7 days. Deacetylationis a more limited process but reaches a steady state after thesame time. Low levels of acetylation and deacetylation wererecorded in wheat. The amounts of suiphanilamide and N⁴ entering and accumulatingin the various tissues were calculated on a water-uptake basisarid these data show that the main site of acetylation is inthe roots and that deacetyla tion occurs to a limited extentin the roots but predominates in stems and leaves.     

The Translocation of Sulphonamides in Higher Plants: II. ENTRY INTO THE LEAVES OF WHEAT

Uptake of a number of suiphonarnides and p-aminobenzoic andsuiphanilic acids can be represented by equations derived fromPick's Law of diffusion. The diffusion constants so derivedhave a Q¹⁰ of the order of 1.4 or 1.7, indicating that the processis primarily physical. The Fick's Law equations provide a measureof the permeability of the system and of the size of the effectivevolume into which the compound is diffusing. Assuming that thebasic process is diffusion from water outside the tissue intowater inside the tissue, the size of the effective volume isconditioned by the absorption of the compound from the aqueousphase of the free space. With sulphanilaniide the effectivevolume is finite while with p-amino benzoic acid the effectivevolume is infinite within the limits of the experiment and concentrationsup to three times that of the treating solution may be attained.A proportion of the suiphanilamide will diffuse out of shootsimmersed in water but p-aminobenzoic acid is held irreversiblyby the tissue.     

新疆伊犁地区侵染蚕豆和三叶草的豌豆花叶病毒的鉴定

从伊犁地区采集的蚕豆花叶病和三叶草花叶病植株获得的病毒分离物,经接种子鉴别寄主,可系统侵染蚕豆、三叶草、豌豆,局部侵染苋色藜和菜豆。可通过蚕豆蚜进行非持久性传播,不通过种子传播。电镜下,病毒粒体呈线条状,平均长度为756nm。在汁液中的热钝化温度是55℃。体外存活期3天。在感病蚕豆叶超簿切片中,可观察到风轮状内含体。血清反应结果证明,该病毒与马铃薯Y病毒、菜豆黄色花叶病毒和菜豆普通花叶病毒有一定相关性。根据上述特性认为,从伊黎地区蚕豆花叶和三叶草花叶植株得到的病毒分离物,为豌豆花叶病毒(PMV)。     

THE PRODUCTION OF ANTIBIOTICS IN SOIL V. BREAKDOWN OF GRISEOFULVIN IN SOIL

When griseofulvin (I; R = Cl, R '= OCH₃), a chlorine-containing antibiotic produced by Penicillium nigricans , was added to fresh garden loam, after an initial lag it disappeared rapidly. When further griseofulvin was added it was inactivated from the start and at rates which increased with each successive addition, suggesting that it was degraded biologically. The numbers of one organism, a Pseudomonas sp., increased in the soil steadily after adding griseofulvin.
When a little soil was added to a solution (pH 7·0) containing inorganic salts and griseofulvin as the sole carbon source, bioassays showed that the griseofulvin disappeared within 5 days. An organism isolated from the broth was identified as the Pseudomonas sp. thought to break down griseofulvin in soil. Griseofulvin also disappeared from a broth at pH 5·0 inoculated with soil, but at this lower pH value a dematiaceous fungus was responsible for its breakdown.
The Pseudomonas sp. also degraded two derivatives of griseofulvin, dechlorogriseofulvin (I; R = H, R'= OCH₃) and the amine (I; R = Cl, R '= NH₂). Cl^– was detected in the solutions after breakdown of griseofulvin by the Pseudomonas ; the amount present agreed well with that calculated on the assumption that all the chlorine in the griseofulvin supplied was liberated as Cl^–. Spectrophotometric examination of the solutions showed no metabolites with the aromatic ring intact, and confirmed the complete breakdown of griseofulvin suggested by the liberation of Cl-.     

MOVEMENT IN THE CYANOPHYCEAE : THE EFFECT OF pH UPON MOVEMENT IN OSCILLATORIA

The effect of pH upon the velocity of translatory movement of Oscillatoria formosa Bory in inorganic culture solutions was determined. Unhindered movement occurred in the range of about pH 6.4 to 9.5. Above and below these limits inhibition was marked. In the unfavorable acid and alkaline ranges inhibition was progressive with exposure time; in the favorable range continuous movement was maintained for 24 hours.     

Intercellular Transport in Plants: II. CYCLOSIS AND THE RATE OF INTERCELLULAR TRANSPORT OF CHLORIDE IN CHARA

The effect of streaming speed on intercellular transport ofchloride has been studied using pairs of internodal cells ofChara. The rate of transport was measured by that fraction ofthe chloride that entered one internode which was transportedout of it into the cells of the node and the next internode.The speed of cytoplasmic streaming was altered by treating thefirst cell with cytochalasin B. The relative rate of intercellular transport depended markedlyon the streaming speed at all speeds up to those found in untreatedcells. The chloride influx into the treated cell did not dependon the streaming speed. It is concluded that the rate of intercellular transport oflow molecular weight solutes in Chara will be normally limitedby the rate at which cytoplasmic streaming brings solute tothe plasmodesmata, rather than by the diffusion permeabilityof the plasmodesmata. This conclusion may well apply to othercharophyte plants, and could in principle apply to higher plants.     

辽宁省番茄花叶病主要病毒和株系的研究

从辽宁南部及沈阳地区采集番茄花叶病样本111个(1985-1987),经鉴定得知主要毒原为番茄的烟草花叶病毒(TMV)占总调查的59.46％。黄爪花叶病毒(CMV)亦有发生仅占总调查的9.00％。还有一些系混合侵染(TMV和CMV)占21.62％。尚未认清毒原种的约占2.70％,接种无症的占7.20％。通过试验认为我省番茄上主要毒原为烟草花叶病毒,并进行了常规鉴定、提纯、电镜观察、光谱测定和血清测定等。对番茄上烟草花叶病毒16个分离物做了株系分化研究,按照Pelbam(1970,1972)〔14、15、16、17〕的抗性分类法应用番茄GCR一套品种接种观察,得知辽南及沈阳地区分布很广的番茄TMV分离物,均属TMV-O株系。故在番茄抗TMV育种中尚应考虑到抗1及2株系的能力。     

Translocation in Plants Possessing Supernumerary Phloem: II. THE INCLUDED PHLOEM OF BOUGAINVILLEA GLABRA CHOISY AND THE BICOLATERAL BUNDLES OF CUCUMBER (CUCUMIS SATIVUS L.)

The translocation path in the included phloem of Bougainvilleaand in the bicolateral bundles of cucumber was studied by exposingyoung branches to ¹⁴CO₂ and detecting the radioactive compoundsby autoradiography. In Bougainvillea, the structure and functionof the phloem system is comparatively uncomplicated and uniform.All phloem bundles, i. e. those which are located in parenchymatoustissue of the central zone and those embedded in the secondaryxylem, become labelled. Exogenous IAA was translocated in thebundles, but the exact mode of translocation was not ascertained.Apical dominance was not affected by girdling. The implicationof this fact is discussed with respect to the translocationof the auxin that determines the correlative inhibition involvedin apical dominance. In cucumber the inner phloem became labelled throughout theplant to a lesser extent than the outer phloem. However, inthe petiole of the assimilating leaf the intensity of the labelwas the same in both inner and outer phloem, although the innerphloem has fewer elements. Below the treated leaf the innerphloem translocated less than the outer phloem. Above this leafthe inner phloem was entirely unlabelled     

MORPHOGENESIS OF THE STAMENLESS-2 MUTANT IN TOMATO. I. COMPARATIVE DESCRIPTION OF THE FLOWERS AND ONTOGENY OF STAMENS IN THE NORMAL AND MUTANT PLANTS

The single gene recessive mutant stamenless-2 (sl₂/sl₂) differs phenotypically from the normal (+/+) only in the stamen structure. Stamens of the mutant plants were laterally free, twisted, shorter, paler in color, possessed abnormal pollen, and bore naked external ovules (E.O.) on the adaxial surface near the junction of anther and filament. Mutant plants grown in the field during summer produced flowers in which a number of carpel-like organs (‘carpelloid stamens‘) with few or no E.O. replaced the stamens. On the other hand, plants grown in the greenhouse during winter possessed flowers with greater number of yellow and pubescent stamens and many E.O. Study of stamen ontogeny revealed that at initiation (up to 100 μ in length) stamen primordia of normal and mutant plants resembled each other. Thereafter the development of stamens in the two genotypes could be distinguished.