Towards the transformation of onions(Allium cepa)

Abstract

This review outlines the potential for developing a reliable transformation system for onions (Allium cepa). A summary of the onion tissue culture literature is presented along with descriptions of the gene transfer systems available. The most suitable regulatory sequences and selective genes that could be used for onion transformation are described, together with the problems which may be encountered following the integration into the particularly large genome of onion. The review proposes likely routes by which transformation and regeneration may be achieved, and suggests possible characteristics of onions which may be altered using such a technique.

Improved method for regeneration and Agrobacterium-mediated transformation of Indian short-day onion (Allium cepa L.)

“…Bhima super via indirect organogenesis An e cient regeneration protocol, DNA delivery system and a selection system are required for successful genetic transformation of any plant species. Previously reported regeneration protocols for Allium cepa showed the dependence of callus induction on cultivars, explants and media compositions (van der Valk et al 1992;Eady 1995;Saker 1997;Eady et al 1998;Zheng et al 1998;Khar et al 2005;Ramakrishnan et al 2013;Sivanesan et al 2015). In this study, we standardized the regeneration protocol for an Indian cultivar, Bhima super, which is one of the commercially important varieties of onion.…”

Genetic regulation of day length adaptation and bulb formation in onion (Allium cepaL.)

“…Onion is a biennial, outcrossing and highly heterozygous crop plant, which is propagated by seeds, bulbs or sets (Eady, 1995). An onion plant is composed of leaves, which arise alternately from a base plate or small flattened stem (bulb), or base plate, which is a vegetative overwintering stage in the life cycle of the plant.…”

Diurnal expression of Arabidopsis Gene homologs during daylength-regulated bulb formation in onion (Allium cepa L.)

“…Numerous onion cultivars have been developed for size, form, colour, pungency, storability, resistance to pests and pathogens, and climatic conditions (Griffiths et al, 2002). Onion is a monocotyledonous bulbous perennial (often biennial), outcrossing and highly heterozygous crop plant, which is propagated by seeds, bulbs or sets (Eady, 1995). An onion plant is composed of photosynthetic leaf blades, which arise alternately from a base plate, or small-flattened scales (bulb), which is the vegetative overwintering stage in the life cycle of the plant (Lancaster et al, 1996).…”