Jana Opatrná

Localization of acid phosphatase in the differentiating root meristem

The localization of acid phosphatase was studied by Gomori’s newer technique and by azo-coupling methods (α-naphthyl phosphate + fast red ITR or fast garnet GBC; AS or AS D phosphate + fast blue B or fast red violet LB) in the root tips ofVicia faba L. on paraffin sections (fixation with Wolman’s acidified ethanol) and on frozen sections (fixation with Baker’s calcium formol). Analogous results were obtained on the material treated in various ways and using different methods. In the broad bean, the reaction is most intense in the cap. In the meristematic zone, the primary core is more intensely stained than the ground parenchyma of the central cylinder. The phloem and xylem poles are usually strongly positive. Using both types of methods on Wolman fixed paraffin embedded material, essentially the same localization of acid phosphatase was found in the root tips ofRicinus communis L.,Lupinus luteus L.,Sinapis alba L.,Allium cepa L. as in the broad bean. InZea mays L. the rhizodermis and the hypodermic layers of the primary core were found to be most active. On sections of Wolman fixed paraffin embedded broad bean the most intense reaction was observed at pH 4.2–4.8. In the same material, both the azo-coupling and the Gomori reaction is inhibited by 10=2 M NaF, but 10−2 M tartaric acid only inhibits the Gomori reaction.AbstractU kořenových špiček bobuVicia faba L. jsme sledovali novější metodou Gomoriho s glycerofosfátem a azokopulačními metodami (α-naftylfosfát + fast red ITR nebo fast garnet GBC; AS nebo ASD fosfát + fast blue B nebo fast red violet LB) v parafinových řezech (fixace Wolmanovou směsí) a vřezech zmrazených (fixace Bakerovým kalciumformolem) lokalizaci kyselé fosfatázy. Stejné výsledky jsme dostali u různě zpracovaného materiálu i při aplikaci různých metod. U bobu je nejintenzjevnější reakce v čepičce, primární kůra jeví v meristematické zóně silnější zbarvení než střední válec. V středním válci bývají silně pozitivní lýkové a dřevní póly. U většiny ostatních testovaných objektů (kořenové špičky skočce obecnéhoRicinus communis L., vlčího bobu žlutéhoLupinus luteus L., hořčice bíléSinapis alba L., eibule kuchyňskéAllium cepa L.) byla zjištěna metodami obou typů v podstatě stejná lokalizace kyselé fosfatázy jako u bobu. U kukuřiceZea mays L. byla nejaktivnější rhizodermis a hypodermální vrstva primární kůry. Na parafinových řezech bobu jsme zjistili nejintenzivnější reakci při pH 4,2 až 4,8; azokopulační i Gomoriho reakce je na tomto materiálu inhibována 10−2m NaF, 10−2m kyselina vinná inhibuje jen Gomoriho reakei.AbstractМы изучали у корневых верхушек бобаVicia faba L. при иомощи нового метода Гомори с глицерофосфатом и при помощи азокопуляционных методов (α-нафтилфосфат + фаст ред ITR или фаст гарнет GBC; AS или ASD-фосфат + фаст блю B нли фаст ред виолет LB) в парафиновых срезах (фиксация смесью Вольмана) и в замороженных срезах (фиксация кальцийформолом Бейкра) локализацию кислой фосфатазы. Одинаковые результаты мы нолучили в по-разному обработанном материале и в случае применения разных методов. У конского боба наиболее интенсивна реакция в калиптре, первичная кора является в меристематической зоне более окрашенной по сравнению с центральным стержнем. В центральном стержне находятся иногда интенсивно положительные лубяные и древесные полосы. У большинства изученных объектов (корневые верхущки клещевиныRicinus communis L., желтого люпинаLupinus luteus L., горчицы белойSinapis alba L., лукаAllium cepa L.) методами обоих типов установлена в сущности такая же локализациь кислой фосфатазы, какая имеет место и у конского боба. У кукурузыZea mays L. самой активной являлась ризодерма и гиподермальный слой первичной коры. На парафиновых срезах конского боба мы установили самую интенсивную реакцю при pH 4,2–4,8; азокопуляционная реакция и реакция Гомори ингирована на этом материале 10−2 M NaF, 10−2 M виноградная кислота тормозит только реакцию Гомори.

The anatomy of the shoot apex of wheat (Triticutn aestivum L.) during transition from the vegetative to the reproductive state and the determination of the primordia

An investigation was made of the anatomical structure of the shoot apex of wheat in the first four stages of organogenesis according toKuperman (1961). It was found that the shoot apex is first covered only with dermatogen (first stage). Then the hypodermis gradually differentiates (second stage) followed by differentiation of the subhypodermis (third stage). In the first stage, the central core of the apex is formed by more or less uniform isodiametric cells so that no zones are distinguishable. During the initiation of the primordia of the assimilating leaves, i.e. in the second stage, a group of larger cells was observed in the apical part of the hypodermis and can be compared with the central zone described in dicotyledons. Under it there is a characteristic group of smaller cells. In the third stage the differences between these groups of cells become less clear and in the fourth stage are no longer observable. No differences were found in the manner of initiating the leaf and bud primordia during the period of ontogenesis studied. There is, however, an alteration in the extent of growth between the bud primordium and the corresponding leaves. Short-day photoperiodic inhibition, always started on the days when the shoot apices were collected for anatomical study, showed that the determination of the primordia of the leaves and axillary buds as parts of the inflorescence is complete by the end of the third stage, at the time when the primordia in the central part of the ear are initiatedAbstractSledovali jsme vývoj anatomické stavby vzrostného vrcholu pšenice v prvních čtyřech etapách organogeneze podleKupermanové (1961). Zjistili jsme, že na vzrostném vrcholu zprvu krytém jen dermatogenem (v 1. etapě) se postupně vytváří hypodermis (v 2. etapě) a subhypodermis (ve 3. etapě). Centrální dřeň vrcholu je v 1. etapě tvořena přibližně stejnými, isodiametrickými buňkami, takže zde není patrná žádná zonace. Při zákládání asimilačních listů, tj. ve 2. etapě jsme pozorovali v apikální části hypodermis skupinu větších buněk, kterou lze srovnávat s centrální zónou popsanou u dvouděložných rostlin, a pod ní charakteristickou skupinu menších buněk. Ve 3. etapě se rozdíly mezi těmito skupinami buněk stírají a ve 4. etapě mizí. Nezjistili jsme rozdíly ve způsobu zákládání listů a pupenů během ontogeneze. Mění se však vztah mezi základy pupenů a okolních listů.Fotoperiodickou krátkodenní inhibicí, započatou vždy ve dnech odběrů vzrostných vrcholů pro sledování anatomické struktury, jsme zjistili, že determinace listů a úžlabních pupenů jako částí květenství je úplná až na konci 3. etapy, tj. v době zakládání primordií ve střední časti klasu.Abstractлеслелолось развитие анатомиуеской структкуры конуеа нарастания шценицы Я. Опатрна, ϕ.Сайдлова, к.Бенеш, лнститут экспериментальной ботаники ЧСАН, в первых этапах органогенеза по куперман. Сначала конус нарастания покрыт тлько дерматогеном (1-ый этап органогенеза). На первом зтапе центральная часть конуса нарастания состоит из почти одинаковых изодиаметрических клеток, такчто никаких зон отличить группу более крупных клеток в гиподермисе. Этагруппа напоминает центральную зону описанную у двудольных растений. Под ней находися хароктеристичестич еская группа более мелких клеток. В течение 3-его этапа

Change of growth correlations in the shoot meristem as the cause of age dependence of flowering in Chenopodium rubrum

Summary Three, six and nine days old seedlings of the short-day plant Chenopodium rubrum show marked differences in the number of inductive cycles they need to evoke floral differentiation. The older the plants, the more inductive cycles and the longer the time required for flowering. We have compared the changes in the anatomical structure of the shoot apex and in the growth of leaf and bud primordia in the age groups mentioned. The speed of floral differentiation does not correlate with the zonal pattern of the shoot apex before induction. Floral differentiation is, however, influenced by the amount of meristematic tissue and the number of leaves initiated. Photoperiodic treatment causes an immediate inhibition of leaf growth in all age groups and, soon after, a release from apical dominance in the apex. Consequently, branching of the shoot apex occurs and the growth of leaf primordia is inhibited. Finally, formation of new leaves in the peripheral zone ceases and differentiation of the terminal flower takes place. If the number of inductive cycles is insufficient, restored leaf organogenesis and a correlated inhibition of bud primordia resume, and a reversal to the vegetative state sets in. The manner of initiation of the lateral organs — leaves and buds — is similar in plants of various age. There are, however, quantitative differences in the number and growth of the lateral organs at the onset of photoperiodic induction as well as during induction and during postinductive changes. These differences in growth cause differences in the number of inductive short-day cycles required for inhibition of vegetative growth and the changes leading to flowering. In younger plants having less well-developed vegetative growth, a single photoperiodic cycle is sufficient to induce flower formation. In older plants a single cycle results in an initial change of the growth correlations between leaf and bud primorida, i.e. in branching, while further floral differentiation requires repeated photoperiodic cycles. Thus, with Chenopodium rubrum the importance of the suppression of leaf growth during the transition from the vegetative to the reproductive state may be demonstrated.

Changes in organ growth ofChenopodium rubrum due to suboptimal and multiple photoperiodic cycles with and without flowering effect

The growth changes of cotyledons, leaves, hypocotyls and roots due to photoperiodic induction in short day plantChenopodium rubrum were investigated in relation to flowering. Six-day old plants were induced by photoperiods with a different number of dark hours. We found that the degree of inhibition which occurred during induction in the growth of leaves, cotyledons and roots similarly as the stimulation of hypocotyl is proportional to the length of dark period. The photoperiods with 12, 16 and 20 dark hours bring about marked inhibition of growth and at the same time induce flowering in terminal and axillary meristems. The inhibitory effect of critical period for flowering,i.e. 8 dark hours, is not apparent in all criteria used and even the flower differentiation is retarded. The photoperiods of 4 and 6 dark hours did not affect growth and were ineffective in inducing flowering even if their number has been increased. The experiments with inductive photoperiod interrupted by light break have clearly shown that growth pattern characteristic for induced plants can be evoked in purely vegetative ones. Such statement did not exclude the possible importance of growth inhibition as a modifying factor of flower differentiation. We demonstrated that the early events of flower bud differentiation are accompanied by stimulation of leaf growth. The evaluation of growth and development of axillary buds at different nodes of insertion enabled us to quantify the photoperiodic effect and to detect the effects due to differences in dark period length not exceeding 2 hours.

Root-shoot correlation linked with photoperiodic floral induction inChenopodium rubrum L.

Inhibition of root growth was observed inChenopodium rubrum under photoperiodic conditions inducing flowering. That this inhibition is mediated by the cotyledons was shown directly by the effect of their excision, which changes the responsiveness of the roots to photoperiodic treatment. On the other hand, decapitation did not lead to such an effect. Some evidence is put forward suggesting that changes in IAA may be involved in these correlations. The existence of two different mechanisms of photoperiodic action in flowering and in root growth is proposed to explain these differences.

Investigation of the endogenous rhythm of flowering inChenopodium rubrum L.

Under the conditions applied in our laboratory 4 1/2 days old plants ofChenopodium rubrum require 2–3 photoperiodic cycles for maximal flowering response, whereas 2 1/2 days old plants are able to flower after having obtained a single inductive cycle. The period length of the free-running rhythm of flowering observed in 2 1/2 days old plants after a single transfer from light to darkness is 30h and the first peak of flowering occurs at about hour 12 in darkness. When a cycle consisting of 16h darkness and 8h light or of 8h darkness and 8h light precedes the long dark period the rhythm is rephased. Rephasing is greater when the light commenced to act on the positive slope of the first peak of the free running rhythm than when it impinged on the negative slope. With an 8h interruption of darkness by light rhythm phase is controlled by the light-on, as well as by the light-off signal. Feeding 0.4 M glucose during the long period of darkness enhanced the amplitude of the flowering response and, moreover, substituted for one photoperiodic cycle.AbstractZa podmínek pěstování používaných v naší laboratoři vyžadují rostlinyChenopodium rubrum ve stáří 4 1/2 dnů po výsevu pro květní indukci 2 až 3 fotoperiodické cykly, kdežto 2 1/2 dnů starým rostlinám stačí jeden cyklus. U 2 1/2 dnů starých rostlin byl po jednorázovém přenosu ze světla do tmy pozorován přirozený endogenní rytmus kvetení, jehož perioda je 30hodinová. První maximum kvetení nastupuje asi 12 hodin po přensu rostlin do tmy. Jestliže před dlouhou periodou tmy byl předřazen cyklus 16h tmy a 8h světla (u 4 1/2 dnů starých rostlin) nebo 8h tmy a 8h světla (u 2 1/2 dnů starých rostlin), byla fáze rytmu posunuta. Posun fáze je větší, začíná-li světlo působit v době vzestupné fáze křivky přirozeného rytmu kvetení než v případě, že dopadne na sestupnou fázi. Je-li tma přerušena 8hodinovou periodou světla, je fáze rytmu určena jak dobou rozsvícení, tak dobou zhasnutí. Byly-li rostliny zásobeny v průběhu dlouhého období tmy glukosou v koncentraci 0,4 M, zvětšila se amplituda rytmu kvetení a navíc nahradila glukosa jeden fotoperiodický cyklus.

The effect of pre-cultivation of tobacco tissue culture on enzymatic separation of protoplasts from various cell types

A method of enzymatic separation of protoplasts from long-term tissue culture ofNicotiana tabacum L. is described. The efficiency of this method is dependent on conditions of separation and on the portion of meristematic cells in the tissue culture. This portion can be increased by pre-cultivations of the tissue on medium containing suitable concentration of hormones. The knowledge of the micromorphology of the filamentous culture enables us to investigate the course of release of protoplasts from various cell types. A preferential lysis of cell walls was observed between neighbouring cells in filaments and the fusion of their protoplasts was recorded. The preservation of cell walls which are not in a contact with other cells may be a result of the cell wall heterogeneity.

Selective histochemical localization of alcohol dehydrogenase in bud primordia cells of wheat shoot apices

During the histochemical investigation of dehydrogenases in the developing shoot apex of wheat plants it was found that the morphologically similar cells of the peripheral meristem may be differentiated according to the differential activity of alcohol dehydrogenase. While the enzyme was not present or exhibited a very small activity only in the tissue of leaf primordia it was highly active in the cells of bud primordia irrespective of the degree of their development and their differential physiological determination.

Changes in the anatomical structure of the shoot apex ofSenecio vulgaris L. during ontogenis in relation to the formation of leaves and inflorescence

An investigation was made of the anatomical structure of the shoot apex ofSenecio vulgaris L. a photoperiodically neutral plant, and compared with the formation of successive leaf primordia along the axis up to the initiation of the terminal inflorescence. In the shoot apex of a germinating plant a central zone can first be distinguished from the peripheral zone which is composed of small and intensely stained cells. Later, a rib meristem appears. At the time of the initiation of the middle (the largest) leaves, the shoot apex has a distinct small central zone and a well developed peripheral zone and rib meristem. Between these zones there is a group of cells dividing in all directions, the subcentral zone. At the time of initiation of the last leaves, the central zone extends to the flanks and gradually ceases to be distinguishable. At the same time, the subcentral zone increases in size. This is caused first by cell division and later, with the initiation of the last, most reduced leaves, by enlargement of the cells. Vacuolization in the inner part of the apex and the arrangement of the superficial cells in rows parallel to the surface of the apex, is a preparatory step to the initiation of the inflorescence.AbstractSledovali jsme vývoj anatomické stavby vzrostného vrcholu u fotoperiodicky neutrální rostlinySenecio vulgaris L. a srovnávali jsme jej s postupným utvářením listů podél osy až k založení terminálního květenství. Ve vzrostném vrcholu klíční rostliny odlišuje se nejdříve centrální zóna od periferní zóny, skládající se z drobnějších a tmavěji se barvících buněk. Později vzniká žebrový meristém. V době zakládání středních, největších listů má vzrostný vrchol odlišenou malou centrální zónu a má dobře vyvinutou zónu periferního a žebrového meristému. Mezi těmito zónami je skupina buněk dělících se všemi směry — zóna subcentrální. V době zakládání posledních listů centrální zóna se rozšiřuje do stran a postupně ztrácí svou odlišnost. Současně roste subcentrální zóna. Tento růst je způsoben nejdříve dělením buněk, později, při vzniku posledních nejredukovanějších listů, také zvětšováním buněk. Vakuolizací vnitřních částí vrcholu a uspořádáním povrchových buněk do řad rovnoběžných s povrchem vrcholu je připraven zaklad terminálního úboru.AbstractПроводились наблюдения над анатомическим строснисм конуса парастастания у ϕотопериодически нейтрального растенияSenecio vulgaris L. л сравненйе с постепенным образованием листьев разных ярусов вплоть до заклки верхушечного соцветия. Во время всхов можно в копусе нарасгания сначала отлить цепральную зону от зоны периϕерической, состоящей из более мелких и интенсивнее окрашиваемых клеток. После этего образуется стержневая меристема. Вовремя закладки средних, самых крупных листьев, имсется в конусе нарастания хорошо отличимая центральная зопа и хорошо развитые зоны периϕерической и стержневой меристемы. Между этими зонами находится группа клеток делящихся во всех направлениях-зона субцентральная. Во времязакладки последвих листьев центральная зона расширяется и постеппо теряет свое отличие. Вмесге с этим увеличивастся субцентральная зона. Эгог рост сначала происходит за счет делсния клеток, позднее, во время образования последних сильно редуцированных листьев, также за счет увеличения клеток. Вакуолизацией внутрених частей конуса парастания и образованием поверхностных слоев мелких клеток приготовляется закладка верхушечного соцветия.

The cytokinin-like effect of a lowered temperature on the micromorphology ofNicotiana tabacum L.

The lowering of the cultivation temperature allows one to alter the growth intensity and micromorphology of tobacco cell strains specifically. By a long-term low temperature treatment the effect is deepened, by transferring inocula into normal cultivation temperature it is repaired. Both the growth and morphogenic effects of the low temperature correspond to those of cytokinins, exhibiting even the same strain specificity.