Zeatin

About: Zeatin is a research topic. Over the lifetime, 2467 publications have been published within this topic receiving 64092 citations. The topic is also known as: Zeatin & (E/Z)-zeatin.

Effect of exogenous cytokinins on dynamics of development and differentiation of infectious structures of the pathogen of wheat powdery mildew

Abstract: The infectious structures for the development and differentiation of Erysiphe graminis DC. f. sp. tritici March., the pathogen of wheat powdery mildew, under the effects of exogenous zeatin was studied by methods of light and electron scanning microscopy. It was shown for the first time that physiologically active substances, specifically phytohormones of the cytokinin type, can affect dimensions of the halo revealed in the pathogen penetration site at cytochemical staining. Treatment with zeatin affected conidia germination and pathogen growth in the ectophytic stage. The concentration curve of the action of zeatin for the number of mature pathogen colonies (6 days after infection) was represented by a multiphase curve with two maxima (1 and 3 μM) and one minimum (1.5 μM). Similar curves have been obtained for the number of normal appressoria and for large halo diameters, which possibly indicates the existence of the factors affecting these both parameters, as well as the final number of pathogen colonies. The obtained data indicate that the origin of the multiphase dose response curve for effect of cytokinins on the development of powdery mildew pathogen is connected with factors that are active at the early stages of pathogenesis.

Detection of cytokinins and auxin in plant tissues using histochemistry and immunocytochemistry.

Abstract: We report a new method for histochemical localization of cytokinins (CKs) in plant tissues based on bromophenol blue/silver nitrate staining. The method was validated by immunohistochemistry using anti-trans-zeatin riboside antibody. Indole-3-acetic acid (auxin, IAA) was localized by anti-IAA antibody in plant tissues as a proof for IAA histolocalization. We used root sections, because they are major sites of CKs synthesis, and insect galls of Piptadenia gonoacantha that accumulate IAA. Immunostaining confirmed the presence of zeatin and sites of accumulation of IAA indicated by histochemistry. The colors developed by histochemical reactions in free-hand sections of plant tissues were similar to those obtained by thin layer chromatography (TLC), which reinforced the reactive sites of zeatin. The histochemical method for detecting CKs is useful for galls and roots, whereas IAA detection is more efficient for gall tissues. Therefore, galls constitute a useful model for validating histochemical techniques due to their rapid cell cycles and relatively high accumulation of plant hormones.

Cytokinins in maturing and germinatingLupinus luteus L. seeds

Abstract: 3H-labelled zeatin riboside (ZR) was applied to pod walls of intactLupinus luteus L. plants. Metabolites present in mature, dry seeds were zeatin nucleotide (ZNT), zeatin riboside (ZR) and zeatin (Z), zeatin O-glucosides and lupinic acid (LA), and the corresponding dihydro-derivatives of the cytokinins listed. Endogenous cytokinins were rapidly metabolised in germinating seeds. In seeds labelled with [3H]ZR for 90 min following a 2 h period of imbibition in water, ZR was actively converted to ZNT and dihydro-ZNT but the prevailing CTK was Z in cotyledons and ZR in embryo axes (EA); later LA and dihydro-LA, and O-glucoside metabolites accumulated. When [3H] zeatin was introduced into imbibing seeds, it was converted to dihydro-ZNT, ZNT, dihydro-ZR, ZR and dihydro-Z; in EA of the Z-labelled seeds, dihydro-ZR and ZR were the main cytokinins. After incubation of the Z-labelled seeds for 6 h in water, the ratios of dihydro-ZNT: ZNT and dihydro-ZR: ZR were, respectively, 20: 1 and 3.4: 1 in EA, and 3.5: 1 and 1.4: 1 in cotyledons.

Effects of Mepiquat Chloride on lateral roots initiation of cotton seedling and its mechanism

Abstract: This paper studied the effects of Mepiquat Chloride (DPC) on initiation and development of lateral roots of cotton seedling,using the upland cotton ( Gossypium hirsutum L.) c.v.Zhongmiansuo 16 and Zhongmiansuo 29 as experiment materials,cultured on glass board after seeds soaking with 400 mg·L -1 DPC solution for 12 hours.DPC increased all the number of lateral roots,root primordia,and the length of the segment where initiated lateral roots and root primordia.It was showed that DPC promoted both the primordia initiation and its development to lateral roots in the experiment of lateral roots removal.Grown under the stress of low temperature,the initiation of lateral roots was also significantly promoted.The levels of endogenous Auxin,Zeatin and Zeatin riboside in the middle segment of primary root were all increased obviously by DPC,which might be the key reason for lateral roots induction.