Plant Regeneration

John J. Finer

John J. Finer

http://www.oardc.ohio-

state.edu/plantranslab/

http://www.oardc.ohio-

state.edu/plantranslab/

For successful production of transgenic plants,

1) DNA delivery2) Regeneration from single

cells

Much of the progress with improvement of crop plants via Biotechnology relies on the ability to introduce DNA into single cells and then, generate whole fertile plants from those single modified cells. The process of generating whole plants from cells is called “regeneration”.

Plant RegenerationUnder the right conditions,

plant tissues regenerate into whole plants via two distinct processes; “somatic embryogenesis” and “shoot morphogenesis”.

Somatic EmbryogenesisFor somatic embryogenesis,

embryos form, which can develop and then germinate into a whole plant.

Somatic Embryogenesis

Somatic embryos are complete entities, similar to seeds. They possess a shoot and root tip and have a complete vascular system. They form under specific conditions that are different from shoot morphogenesis.

Somatic Embryogenesis

An auxin is usually applied for induction of somatic embryogenesis. Nitrogen and carbohydrate balance are also important. Embryos usually develop, once they are transferred to a medium with no auxin.

Soybean Embryogenesis

Soybean Embryogenesis

InductionProliferation

Development

Germination

Plant Recovery

Starting MaterialImmature seeds

Shoot Morphogenesis

For shoot morphogenesis, shoots form, which must be excised to form roots before they can be transferred to the soil.

Shoot Morphogenesis

Shoots can be formed directly from the starting plant material or arise from a mass of proliferating, unorganized piece of plant tissue called a callus.

Shoot MorphogenesisShoot formation is usually induced following placement of tissues on media containing a high cytokinin to auxin ratio. Media that contain inappropriately higher levels of auxin can cause callus to form.

Shoot MorphogenesisPlant regeneration from shoots required the formation of roots on excised shoots. Root formation can be spontaneous or induced by rooting hormones which contain auxin. Rooted shoots can then be transferred to soil for plant establishment.

Cotton

Poplar

Xmas Cactus Sunflower

Soybean Ohio Buckeye

Which are somatic embryos/shoots?Somatic Embryo

Somatic EmbryoSomatic Embryo

Shoot morphogenesis

Shoot morphogenesis

Shoot morphogenesis

For further information, contact:

John J. FinerDepartment of Horticulture and Crop

ScienceOARDC/The Ohio State University1680 Madison Ave.Wooster, OH 44691Tel: 330-263-3880Fax: 330-263-3887e-mail: finer.1@osu.edu