RESUMEN
We studied the influence of the preconditioning of wheat germ (Triticum aestivum L.) with 0.4 microM 24-epibrassidinole (EB) on the growth and hormone status of plants under the influence of 2% NaCl. The preconditioning with EB promoted the lowering of the extent of the damaging influence of pickling on the growth of germs. The important contribution to the realization of the protective action of EB in the preconditioning of plants is probably that of its ability to lower the level of stress-induced abscisic acid accumulation and the decrease in the content of indole-acetic acid. At the same time, the cytokinin concentration in plants preconditioned with EB under pickling was practically the same as in plants without stress. This fact combined with data about the ability of EB to induce the increase in cytokinin content in wheat, obtained before, allowed us to assume that the protective action of EB on plants is connected, first of all, with the prevention of the increase in level of hormones of cytokinin nature under pickling.
Asunto(s)
Adaptación Fisiológica/efectos de los fármacos , Colestanoles/farmacología , Reguladores del Crecimiento de las Plantas/metabolismo , Salinidad , Esteroides Heterocíclicos/farmacología , Triticum/efectos de los fármacos , Ácido Abscísico/metabolismo , Brasinoesteroides , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Cloruro de Sodio/farmacología , Triticum/crecimiento & desarrollo , Triticum/metabolismoAsunto(s)
Colestanoles/química , Colestanoles/farmacología , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Oxidorreductasas/biosíntesis , Raíces de Plantas/enzimología , Semillas/enzimología , Esteroides Heterocíclicos/química , Esteroides Heterocíclicos/farmacología , Triticum/enzimología , Brasinoesteroides , Reguladores del Crecimiento de las Plantas/metabolismo , ARN/metabolismo , ARN Mensajero/metabolismo , Esteroides/química , Factores de Tiempo , Rayos XRESUMEN
Effects of 20 nM wheat germ agglutinin (WGA) on relative growth rate, mitotic index (MI) and the cell area in the root extension zone were investigated in seedling of Triticum aestivum L. under the influence of 2% NaCl. It was elucidated that pretreatment of wheat seedling with WGA prevented a salinity induced inhibition of root cell growth, and accelerated the restoration of cell growth after stress removal. The protective WGA effect on root cell growth may be due, presumably, to reorganization of phytohormone balance caused by WGA treatment, which could lead to accumulation of LAA and decrease in the ABA level.
Asunto(s)
Reguladores del Crecimiento de las Plantas/farmacología , Cloruro de Sodio/farmacología , Triticum/efectos de los fármacos , Aglutininas del Germen de Trigo/farmacología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Cloruro de Sodio/antagonistas & inhibidores , Triticum/crecimiento & desarrolloRESUMEN
A study was made of cell division activity and hormonal status in roots of 4 day old wheat seedling treated with wheat germ agglutinin (WGA). The revealed stimulating effect of WGA on mitotic index (MI) and cell area in root extension zone was specific for this lectin, because gliadin, taken as a control protein, caused no changes in growth parameters. Phytolectins (phytohemagglutinin and concanavalin A) possessing properties of mitogens rendered no such essential influence on cell growth of wheat. Immunoassay has shown that WGA-treatment leads to accumulation of auxins and cytokinins in roots. This suggest participation of WGA in regulation of MI of meristem cells in roots of seedlings during their interaction with phytohormones.
Asunto(s)
Triticum/efectos de los fármacos , Aglutininas del Germen de Trigo/farmacología , División Celular/efectos de los fármacos , Citocininas/biosíntesis , Ácidos Indolacéticos/biosíntesis , Índice Mitótico , Reguladores del Crecimiento de las Plantas/metabolismo , Raíces de Plantas/efectos de los fármacos , Plantones/efectos de los fármacos , Triticum/crecimiento & desarrollo , Triticum/metabolismoAsunto(s)
Colestanoles/farmacología , Citocininas/metabolismo , Reguladores del Crecimiento de las Plantas/farmacología , Plantones/efectos de los fármacos , Esteroides Heterocíclicos/farmacología , Triticum/efectos de los fármacos , Ácido Abscísico/metabolismo , Brasinoesteroides , Ácidos Indolacéticos/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/fisiología , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Triticum/crecimiento & desarrollo , Triticum/metabolismoRESUMEN
The review considers the mechanisms of gene transcription regulation by phytohormones, which play an important role in controlling major genetic programs in plants. The focus is cis-regulatory elements, which occur in the phytohormone-responsive gene promoters and, along with trans-acting factors and other proteins, ensure the effective reception of the hormonal signal.