BACKGROUND AND AIMS Understanding the fate and dynamics of cells during callus formation is essential to understanding totipotency and the mechanisms of somatic embryogenesis. Here, the fate of leaf explant cells during the development of embryogenic callus was investigated in the model legume Medicago truncatula. METHODS Callus development was examined from cultured leaf explants of the high...

BACKGROUND Morphological and ploidy changes of the arsenic hyperaccumulator, Chinese brake fern (Pteris vittata) callus tissue are described here to provide insight into fern life cycle biology and for possible biotechnology applications. Pteris vittata callus was studied using transmission and scanning electron microscopy, and flow cytometry. RESULTS Callus induction occurred both in light a...

The study was undertaken to examine the effect of two synthetic auxins on somatic embryogenesis and plant regeneration from mature embryo explants of 16 onion cultivars. Cotyledons were removed from the embryos and remaining portions were cultured on MS medium supplemented with 1.0 mg/L 2,4-D and 5.0 mg/L picloram alone or in combination (1.0 mg/L 2,4-D + 2.5 mg/L picloram) to produce embryogen...

From 8-10 days old seedlings of Pisum sativum L. (variety AP-1), various parts root, cotyledon as well as leaf were separated to use as explants. Root and cotyledonary explants did not show any response on MS (Murashige & Skoog) media supplemented with 2, 4-D at a concentration of 5 ppm. However, leaf explants showed callus formation on this media. The callus so formed was subcultured on MS med...

During plant growth and development, the phytohormone auxin induces a wide array of changes that include cell division, cell expansion, cell differentiation, and organ initiation. It has been suggested that the actin cytoskeleton plays an active role in the elaboration of these responses by directing specific changes in cell morphology and cytoarchitecture. Here we demonstrate that the promoter...

To establish a high-efficiency system of isolated microspore culture for different barley genotypes, we investigated the effects of nitrogen sources and concentrations on callus induction and plant regeneration in different barley genotypes. The results showed that the organic nitrogen sources greatly increased the callus induction, and the great reduction of total nitrogen sources would signif...

Follow-up radiographs are important to assess proper alignment and adequate healing of a fracture. The formation of a callus is one characteristic used to follow these features, but the timing and size of its appearance is variable. Therefore, when to expect to see a callus on radiographs requires a general understanding of the fracture healing process and the many variables that can affect cal...

Tobacco mosaic virus (TMV) concentrations in tobacco callus tissues grown on the media containing cu-naphthaleneacetic acid (NAA) and kinetin at different concentrations were assayed periodically during successive cultures. Tobacco callus originally raised from the TMV-infected tobacco stem became green and compact when serially cultured on the medium containing lower concentration (0.01-o. 1 m...

The omission of sucrose from the basal medium stimulated callus formation in bud explants of Citrus sinensis (L.) Osbeck. Moreover, it increased the abscisic acid-induced callus proliferation reported earlier in the presence of 5% sucrose (Altman and Goren, Physiol. Plant. 32: 55, 1974). The inhibition of callus formation by the addition of sucrose was not due to the high osmotic potential of t...