3. Suspension cell culture

Question 1

What are the applications for suspension cell cultures?

Answer 1

1. Plant material for protoplast isolation
2. Optimisation of protocols for cell differentiation or plant regeneration
3. Induction and selection of mutations (somaclonal variation and in vitro early selection)
4. Study of primary and secondary metabolism
5. Secondary metabolites production (anthocyanins (grape) anthocyanins (Prunus spp) aromas (strawberry))
6. Micropropagation and plant regeneration

Question 2

Please name the main groups of tissue cultures?

Answer 2

1. Callus (or tissue) cultures
2. Suspension (or cell) cultures
3. Protoplast cultures
4. Anther cultures

Question 3

What is a suspension culture?

Answer 3

• Populations of plant cells and small cell clumps, dispersed in an agitated, aerated, liquid medium

Question 4

What is a Protoplast culture?

Answer 4

• The culture of plant cells that have been isolated without a cell wall

Question 5

What are anther cultures?

Answer 5

• The culture of complete anthers containing immature pollen microspores
• The objective is usually to obtain haploid plants by the formation of somatic embryos directly from the pollen

Question 6

What are the main steps for optaining cell cultures?

Answer 6

1. Induction and maintenance of callus (callus = mass of parenchymal cells in active and in disorganized division)
2. Transfer of callus in liquid substrates and obtaining of culture in suspension

Question 7

What are the factors inducing the callus formation?

Answer 7

1. Type of explant (often they are organs from plants cultured in vitro)
2. Type of substrate (or culture media)
3. Temperature 22-28°c
4. 100% humidity
5. Light/dark conditions
6. Development of the primary callus
7. Callus maintenance to be transplanted after 3–8 weeks (secondary callus)
8. Transplant of the calluses every 4 weeks

Question 8

Growth curve of cells in suspension culture: what are the main growth phases?

Answer 8

1. a lag phase
2. a period of exponential and then linear growth
3. a period when the rate of growth declines
4. a stationary phase when growth comes to a halt.

Question 9

What´s the difference between batch and continuous cultures?

Answer 9

• Many different methods of suspension culture have been developed. They fall into two main types:

1. Batch cultures in which cells are cultured in a fixed volume of medium until growth ceases
2. Continuous cultures in which cell growth is maintained by continuous replenishment of sterile nutrient media.

Question 10

Missing the experimental steps of: TRANSFER OF THE CALLUS IN LIQUID SUBSTRATE AND OBTAINING OF CULTURE IN SUSPENSION