PLANT CELL AND TISSUE CULTURE

Flashcards covering plant cell and tissue culture, including techniques, advantages, disadvantages, and applications.

What is Plant Tissue Culture (PTC)?

Growing and multiplication of plant cells, tissues, and organs on solid or liquid media under controlled conditions.

What are the benefits of Plant Tissue Culture over traditional propagation methods?

Faster growth, multiplication of difficult-to-propagate plants, production of genetically identical clones, disease-free seed germination, long-term storage, virus eradication, genetic manipulation, and plant breeding.

What are the advantages of Plant Tissue Culture?

Rapid production of new plants, small space requirement, precise control of conditions, inheritance of desirable characteristics.

What are the disadvantages of Plant Tissue Culture?

Uniform genetic makeup leading to vulnerability to diseases, no new beneficial characteristics, danger of reducing the gene pool.

What factors provide the chemical and physical needs of cells cultured in vitro?

The culture vessel, growth medium, and external environment (light, temperature).

What are the basic components of plant cell culture media?

Essential mineral ions, organic supplements (amino acids and vitamins), and a fixed carbon source (sugar, usually sucrose).

How are essential elements further divided for practical purposes in plant cell culture media?

Macroelements, microelements, and an iron source.

What are the important elements for plant nutrition and their functions?

Nitrogen, potassium, calcium, magnesium, phosphorus, sulfur, chlorine, iron, manganese, cobalt, copper, zinc, molybdenum.

What are the forms of plant cell culture media and what do they depend on?

Used in either liquid or solid forms, with solid media requiring gelling agents like agar to support surface growth.

What gelling agents can be used for solidifying plant cell culture media?

Agar, agarose, and gellan gums.

What is the role of Auxins in plant tissue culture?

Promote cell division and cell growth. IAA is common, but 2,4-D is more stable and frequently used.

What is the role of Cytokinins in plant tissue culture?

Promote cell division, with synthetic analogues like kinetin and BAP being frequently used due to the cost and instability of naturally occurring cytokinins.

What is the role of Gibberellins in plant tissue culture?

Regulate cell elongation and are important in determining plant height and fruit-set. GA3 is the most common one used in plant tissue culture.

What is the role of Abscisic Acid (ABA) in plant tissue culture?

Inhibits cell division and is used to promote specific developmental pathways like somatic embryogenesis.

What is the role of Ethylene in plant tissue culture?

Controls fruit ripening, with its use being limited in plant tissue culture due to its potential to inhibit growth and development.

How do auxin to cytokinin ratios affect plant development?

Intermediate ratios promote callus formation, low auxin to cytokinin ratios promote shoot formation, and high auxin to cytokinin ratios promote root formation.

Which explant is generally most effective for culture initiation?

Younger, more rapidly growing tissue.

What occurs when an explant source in a medium containing minerals, vitamins, and hormones?

Callus production, plantlet propagation.

What is Organ Culture?

Involves maintaining the organization of an organ, consisting of tissues and cells performing a specific function.

What aspects decide the size of plant tissue culture explants?

Surface size, volume, and cell number, as well as the developmental stage.

How can root cultures be established in vitro?

Explants of the root tip and grows unlimited as roots are indeterminate organs.

What do the tips of shoots cultured produce in vitro?

Producing clumps of shoots from axillary or adventitious buds. It can be used for clonal propagation.

What does Nodal or Axillary Bud Culture consist of?

A piece of stem with axillary bud culture, with or without a portion of shoot.

What is Embryo Culture?

The aseptic isolation and growth of sexually produced embryos in vitro to obtain viable plants.

What are the applications of Embryo Culture?

Rescuing embryos from incompatible crosses, overcoming dormancy, germinating immature embryos of orchid seeds, and shortening breeding cycles.

What is a Callus?

An unorganized or undifferentiated mass of cells produced either in culture or in nature.

What does Callus induction and maintenance involve?

Subculturing every 3-5 weeks and repeated subcultruing causes friability of callus

What are the developmental stages of callus cultures?

Induction, division, and differentiation.

What occurs as subculture proceeds for Callus Tissue?

Loss of organogenic response, and changes in chromosomal structure or number.

What are the applications of Callus Culture?

Studying nutrition requirements, cell and organ differentiation, somaclonal variations, developing cell suspension cultures, genetic transformation, and production of secondary metabolites.

What are the different categories of Suspension Culture?

Batch culture, continuous culture, and immobilized cell cultures.

How are cells in suspension assessed?

Mitotic Index (MI), Packed Cell Volume (PCV), Cell Fresh Weight, Optical Density, and tests for cell viability.

What opportunities does cell culture offer?

Studying single cells and groups of cells, isolating protoplasts, cell cloning, developing cell lines for resistance, and scaling up technology using bioreactors.

What is a protoplast?

The entire plant cell without its cellulosic cell wall

What are Subprotoplasts?

Subprotoplasts that do not contain the entire contents of plant cells and include the following: Cytoplast (entire cytoplasm of a cell), Miniprotoplast / karyoplast (contain a nucleus surrounded by cytoplasm and the original plasma membrane), Microplast (contains only a fraction of cytoplasm and outer membrane), Microprotoplast (contain a few chromosomes and a fraction of the cytoplasm).

How can protoplast viability be tested?

Observing cytoplasmic streaming, exclusion of Evans Blue dye, changes in protoplast size due to osmoticum level changes, photosynthetic and respiratory activity, and FDA or CFW test.

What are the two types of Androgenesis?

Direct Androgenesis and Indirect Androgenesis.

What is the basic principle of anther and pollen culture?

Production of haploid plants exploiting the totipotency of microspores.

What are methods of Pollen isolation?

Squeeze culture, float culture, and slit technique.

What are the advantages Of Haploids/Anther Culture/Pollen Culture?

Useful in cytogenetic studies, production of homozygous inbreds, tracing parents of hybrids, mutation studies, and development of pure lines.

How can Induced duplication be achieved in Chromosomes Doubling In Haploid?

Colchicines treatment

What is Ovary Culture?

Culture of unfertilized ovaries to obtain haploid plants from the egg cell or other haploid cells of the embryo sac.

What are the Advantages of Ovary Culture?

Male sterility in crop species, in vitro pollination and fertilization, embryo rescue, production of parthenogenetic haploids, and understanding fruit development.

When is Ovule Culture mainly tried?

Where an embryo aborts very early, and embryo culture is not possible due to difficulty of its excision at a very early stage.