Morphogenesis and totipotency, Biology

Morphogenesis and Totipotency

A chlamydomonas mother cell gives rise to two daughter cells by a simple division. But a leaf cell cannot give rise to a new plant except in cases like Bryophyllum or Kalanchoe. What makes a daughter cell of a zygote to loose the 'potential' to develop into a whole plant? Or if all the daughter cells possess this potential- i.e. if they are totipotent-why it does not express? These questions troubled Haberlandt-hundred years ago. He postulated that any living plant cell should be able to grow into a full plant. He experimented with mesophyll cells at a time when tissue culture had not been unheard for. His experiments failed because we now know that isolated mesophyll cells are not really easy to grow to unleash their morphogenetic potential.

F.C. Steward-who took up this work sixty years later-successfully cultured whole carrot plants from carrot phloem parenchyma cell. He published the papers in the American Journal of Botany in the late 1950's. Steward and his coworkers took 2 mg. tissues of secondary phloem of carrot roots and grew them in special flasks with nipples or tubes called tumble tubes. The medium was whites' medium with coconut water. These tubes/flasks were mounted on a wheel that was rotated on a shaft at the rate of 1 r.p.m. So that the pieces were alternately aerated and bathed in the liquid medium. There was an enormous increase in size of the explants. A callus ensued. A few peripheral cells slaughtered off into the medium and started dividing and gave rise to clumps,-occasionally with roots these could be transferred to semi-solid medium in (still) tubes. Shoots arose opposite the roots to yield full plants. Subsequently other parts were also used to, demonstrate cellular totipotency.

Posted Date: 1/24/2013 1:24:00 AM | Location : United States

Related Discussions:- Morphogenesis and totipotency, Assignment Help, Ask Question on Morphogenesis and totipotency, Get Answer, Expert's Help, Morphogenesis and totipotency Discussions

Write discussion on Morphogenesis and totipotency
Your posts are moderated
Related Questions
what is working of heart

Q. How different are the swimming strategies in chondrichthyes and in osteichthyes? Why do sharks need to agitate their body to swim while bony fishes do not? Bony fishes have

Describe in brief about Pseudoisoehromatic Plates test Commonly known as Ishihara's plates, these reveal one pattern to the normal eye and another to the colour deficient. Colo

Single chromosome of a pair is known as homologue.In Homologous pair two identical chromosomes are there. Each one chromosome in a Homologous pair is known as Homologue.

Explain about Phytopinax written by Caspar Bauhin? A significant contribution to taxonomy was made at this time by Caspar Bauhin. His 'Phytopinax' (1596) described 2700 species

Explain diet from Lifestyle Risk Factors ? The lifestyle factors are the way of living of an individual and comprise of the diet, smoking, alcohol, physical activity and stress

Prevention and control The organism is sensitive to penicillin, tetracycline and other broad-spectrum antibiotics. Newer generation drugs are being used for the treatment of affec

Explain about the Micronutrient Deficiencies? Micronutrient deficiencies are more common during calamities. Can you guess, why? This is due to the lack of diversified food item

Explain what is pulse ? Examination of peripheral pulses as a very important step in cardiovascular examination. A normal pulse has upstroke (anacrotic limb) followed by a down

Determine Protein needs during pregnancy period? Altogether, 925 g of protein are deposited in a normal foetus and maternal accessory tissues and considering the dietary protei