In vitro raised shoots of Plumbago rosea L. were infected with A4 strain of Agrobacterium rhizogenes to initiate hairy root formation, which produced 3.0±0.33 hairy roots per incision on explants in 20 d incubation. Southern blot analysis confirmed the integration of T-DNA into the genome of the roots. The hairy roots were cultured on MS agar medium supplemented with 2.0 mg/L BAP to induce the ...

Gesellschaft für Biotechnologische Forschung, Mascheroder Weg, D-3300 Braunschweig-Stöckheim, Bundesrepublik Deutschland Z. Naturforsch. 42c, 69—72 (1987); received August 21/September 22, 1986 Agrobacterium rhizogenes, Alkaloids, Nicotine, Cytisine, Nicotiana, Spartium The growth of root hairs from stems of Nicotiana tabacum and Spartium junceum was induced by Agrobacterium rhizogenes. Stem ro...

The development of shoot-borne roots, or adventitious roots, is indispensable for mass propagation of elite genotypes. It is a complex genetic trait with a high phenotypic plasticity due to multiple endogenous and environmental regulatory factors. We demonstrate here that a subtle balance of activator and repressor AUXIN RESPONSE FACTOR (ARF) transcripts controls adventitious root initiation. M...

In the transformation semigroup (X, S) we introduce the height of a closed nonempty invariant subset of X, define the transformed dimension of nonempty subset S of X and obtain some results and relations.

An important mechanism for Al(3+) tolerance in wheat is exudation of malate anions from the root apex through activation of malate-permeable TaALMT1 channels. Here, the effect of ethylene on Al(3+)-activated efflux of malate was investigated using Al(3+)-tolerant wheat genotype ET8, which has high expression of TaALMT1. Exposure of ET8 plants to Al(3+) enhanced ethylene evolution in root apices...

Here, efficient plantlet regeneration via somatic embryogenesis from Panax quinquefolium hairy roots was reported. Callus development was optimal on MS medium containing 2,4-dichlorophenoxyacetic acid (1 mg l) and -naphthalene acetic acid (1 mg l). After a 4-week growth, calli were transferred onto MS medium with different combinations of plant growth regulators (PGRs). The highest embryogenesi...

A cDNA clone that encodes a feedback-insensitive anthranilate synthase (AS), ASA2, isolated from a 5-methyl-tryptophan (Trp) (5MT)-resistant tobacco cell line under the control of the constitutive cauliflower mosaic virus 35S promoter, was introduced into the forage legume Astragalus sinicus by Agrobacterium rhizogenes with kanamycin selection. The 35S-ASA2 gene was expressed constitutively as ...

Cytokinins are a class of plant-specific hormones that play a central role during the cell cycle and influence numerous developmental programs. Because of the lack of biosynthetic and signaling mutants, the regulatory roles of cytokinins are not well understood. We genetically engineered cytokinin oxidase expression in transgenic tobacco plants to reduce their endogenous cytokinin content. Cyto...