Daksha Sankhla

Effect of Paclobutrazol on the Activities of some Enzymes of Activated Oxygen Metabolism and Lipid Peroxidation in Senescing Soybean Leaves

Summary Nineteen-day-old soybean [Glycine max (L.) Merr. cv. A 2] plants were treated with soil-applied paclobutrazol, an antigibberellin growth inhibitor, at the rate of 125 µg per 10 cm pot. The plants were then grown for 14 days under a 14 hr photoperiod after which they were transferred to the dark for senescence induction. At the end of the 14 day period in the light, treated plants exhibited higher chlorophyll (Chl) content and higher activities of catalase and glycolate oxidase compared to controls. In contrast, control leaves had higher activities of superoxide dismutase and a higher content of malondialdehyde (MDA), a product of lipid peroxidation. Upon transfer to dark, Chl and protein content declined in both control and treated plants, but the decline was much faster in controls. The activity of catalase declined markedly in controls while remaining constant in reated plants. Peroxidase and superoxide dismutase activities and MDA content increased in controls in the dark but remained relatively constant in treated plants. These results suggest that paclobutrazol delays dark-induced senescence in attached soybean leaves and that this delay is associated with the maintenance of catalase activity and the prevention of the senescence-linked rise in peroxidase activity and lipid peroxidation.

Abscisin II-kinetin interaction in leaf senescence

Abscisin II, eine natürlich vorkommende, die Abtrennung beschleunigende Substanz, erhöhte das Altern von Blattscheiben vonArabidopsis sehr. Dieser Effekt von Abscisin II blieb jedoch beinahe vollständig unterdrückt, wenn Kinetin gleichzeitig zugefügt wurde.

Abscisin II-kinetin antagonism in growth ofIpomea cotyledonary callus

Die rund l i chen P l g t t c h e n wurden zuers t von OOLDIN [5] in e inem W e M V W i r t gefnnden, wobei i hnen abe t keine besondere A u f m e r k s a m k e i t gewidmet wurde . D a n k der Gefgll igkeit yon He r rn Dr. Z. PoLs (Prag) k o n n t e n wir anch den t yp i s chen yon H O L ~ S [3] beschr iebenen Sta ture des W e M V anschaf fen . Bet der l i ch tmikroskop i schen Durch s ich t der m i t d iesem Virus inf iz ier ten T a b a k b l g t t e r k o n n t e n wir ebenfalls die rund l i chen PlXt tchen anff inden, die der F o r m u n d S t r u k t u r nach unse ren P l g t t c h e n ghneln . t i sch: W/ ih rend des P a c h y t g n s u n d des Diplot~ins l i nden sich in der H a u p t s a c h e 80 s -Par t ike l ; w&hrend des Dip lo tgns u n d der Diakinese wurden p rak t i s ch keine P o l y s o m e n gefunden . t n der Me taphase t r i t t s o d a n n eine V e r m e h r u n g der Polys o m e n F r a k t i o n e n auf, die i m T e t r a d e n S t a d i n m ein M a x i m u m erreicht. Somi t is t die Meiose gekoppel t m i t ether E l imin i e rung des po lysomalen Mater ia ls der diploiden Pol lenmut terze l le . Die

Lettuce Seed Germination: Interaction between Auxin and 2-Chloroethanephosphonic acid (Ethrel)

Auxins (NAA, IAA) inhibited the seed germination of lettuce cv. Cabbage. The auxin-indueed inhibition of seed germination could be overcome if 2-chlorethanephosphonic acid (CEPA, ethrel) or kinetin was added simultaneously. Thus ethylene can also modulate the action of endogenous inhibitors in seed germination.AbstractAuxiny (NAA, IAA) inhibovaly Klíčení semen salátu cv. Cabbage. Inhibice Klíčení semen indukovaná auxiny může být anulována současnou aplikacé 2-chlorethanfosfonové kyseliny (CEPA, ethrel) nebo kinetinu. Ethylen tak může též pozměnit působení endogenních inhibitorů při klíčení semen.

Morphactin-gibberellin interaction in lettuce seed germination and seedling growth@@@Interakce morfaktinu a gibberelinu při klíčení a růstu klíčních rostlin salátu@@@Взаимодействие морфактина с гибберелином при прорастании семян и росте проростков салата

Morphactin-butylester (a flourene-9-carboxylic acid derivative) inhibited seed germination of two strains of lettuce. Morphactin induced inhibition of germination could be partially or wholly reversed by simultaneous addition of gibberellic acid. However, gibberellic acid played very little part in reversing the inhibitory effect of morphactin on seedling growth. It is concluded that gibberellin can not reverse all the growth effects induced by morphactin.AbstractButylester morfaktinu (derivát fluoren-9-karboxylové kyseliny) inhibuje klíčení semen dvou odrůd salátu. Inhibice klíčemí indukována morfaktinem může být zmírněna až zrušena současným přidáním kyseliny giberelové. Inhibice růstu klíčních rostlin způsobena morfaktinem je však kyselinou giberelovou ovlivňována jen velmi málo. Giberelin tudíž interaguje s morfaktinem jen v některých případech.AbstractБутиловый эфир морфактина (производное флюорен-9-карбоксиловой кислоты) подавляет прорастание семян двух сортов салата. Ингибиция прорастания семян вызваная морфактином уменьшается или полностью устраняется одновременным применением гибберелловой кислоты. Подавление роста проростков вызваное действием морфактина однако одновременным применением гибберелина почти не изменяется. Следовательно гибберелин влияет на действие морфактина не во всех случаях.

Growth and organogenesis in moth bean callus cultures as influenced by triazole growth regulators and gibberellic acid

The triazole plant growth regulators, paclobutrazol and uniconazole, reduced in vitro growth of moth bean callus by 20–25% when added to the culture medium at 1 mg/L (3.4 μM). The addition of 10 mg/L (29 μM) gibberellic acid (GA3) to the culture medium in combination with the triazoles restored callus growth to a level equivalent to that of the untreated control. GA3 alone had little effect on callus growth. When added to a regeneration medium at 1 mg/L both paclobutrazol and uniconazole reduced the percentage of cultures that formed roots, as well as the mean number of roots per culture. In contrast, GA3 increased root formation and counteracted the inhibitory effects of the triazoles on rooting. The addition of triazoles or GA3 to the regeneration medium reduced the formation of green meristematic nodules, which are precursors of shoots in moth bean callus. When callus was grown in the presence of either paclobutrazol or uniconazole, subsequent root and green meristematic nodule formation were reduced upon transfer to a growth regulator-free regeneration medium. The results of this study indicate that exposure of moth bean callus tissue to micromolar concentrations of triazoles or GA3 can significantly alter in vitro growth and differentiation.

In vitro growth, metabolism and regeneration of moth bean callus as influenced by flurprimidol

Summary Flurprimidol (FLP) is an experimental gibberellin biosynthesis inhibitor whose biological properties have not been fully characterized. Addition of FLP (0.5-2.0 mg 1-1) to a callus medium reduced both fresh and dry weights of moth bean (Vigna aconitifolia) callus after 21 days. The concentrations (fresh weight basis) of total sugar, proline, soluble protein, and phenols in callus tissue were all increased by FLP relative to the control. In addition, the activities of peroxidase, protease, RNase, alanine aminotransferase, and aspartate aminotransferase were all greater in FLP-treated cultures than in controls. The presence of 1 mg 1-1 FLP in a regeneration medium reduced the percentage of cultures exhibiting roots as well as the mean number of roots formed per culture. Likewise, FLP reduced the formation of green meristematic nodules which are forerunners of shoots in moth bean callus.

Growth response of excised ovaries of reseda odorata in sterile culture

In the basal growth medium only the ovaries excised 15 days after pollination reached maturity. In a medium containing IAA (5ppm) and kinetin (0.5ppm) ovaries excised even 10 days after polliration produced viable seeds.Young ovaries formed in the pedicel region a callus, which later differentiated into roots; older ovaries (excised 15 days after pollination) produced callus tissue and roots from the ovary wall.AbstractV základním kultivačním prostředí dorostly do dospělosti jen semsníky odebrané z rpstliny až 15 dní po opylení. V médiu obsahujícím 5 ppm kyseliny indolyloctové a 0,5 ppm kijietinu se vyvinula klíčivá semena i v semenícich. odebraných již 10 dní po opylení. Na mladšich semenících se vytvářel v oblasti květní stopky kalus, který později diferencoval na kořeny, na semenících odebraných později (15 dní po opylení) se vytvářel kalus a později kořeny ze stěny semeníku.AbstractВ ОсНOВНОй среде дОрОе ли иО ЗрелОгО сОсTОяНи я лишь семеННиКи, ВЗяТ ые с расТеНия спусТя 15 дней пОсЛе Оиы леНия. В среде, сОдержа щей 5 мг/Л ИУК и 0,5 мг/л Кине ТиНа, ра3Вились ВсxОЖие семе На и в семеННиКах ВЗяТ ьbх с расТеНия уже спу сТя 10 дней пОсАВе опьыиеНия. Ηа бОлее мОЛОдых семе ННиКах в ОбЛасти цВеТ оНожКи ОбраЗОВыВаЛс я КалЛус, диф-фереНцирующийся пОЗ ДНее в КОрни, а На сеMеН НиКаx, снятых в бОЛее пО ЗдНюю фаЗу (15 Зней пОсле ОлылеНия) ОбраЗоВыВался каллу с, а пОЗдНее кОрНи и3 ст еНоК семеННиКа.