rpc00061: Glycyrrhiza echinata Ak-1 callus culture

Note

  1. Components
  • Two 9-cm Petri dishes, containing cells placed on semi-solid medium
  1. Notice
  • Subculture the cells to fresh medium immediately after arrival.
  • Do not store the cell culture in a refrigerator and a freezer.
  • Maintain aseptic conditions of the cell culture, and work in a laminar flow cabinet.
  1. Summary
  • Culture medium: MS medium, 0.1 mg/L 2,4-D, 1 mg/L kinetin, 0.9% (w/v) agar, pH 5.8 (medium no. 50)
  • Culture conditions: 25–27°C, dark
  • Subculture: 28-day intervals
  1. Citation of cell line

    When results obtained by using this cell line are published in a scientific journal, it should be cited in the following manner: “Glycyrrhiza echinata Ak-1 cell line (rpc00061) was provided by the RIKEN BRC which is participating in the National BioResource Project of the MEXT/AMED, Japan.”

Introduction

Licorice Ak-1 cell line was established from a leaf and a petiole of Glycyrrhiza echinata L. (Nakamura et al. 1999 [1]). The Ak-1 callus culture has the capacity for producing an isoflavonoid-derived phytoalexin (medicarpin) by elicitor treatment. The Ak-1 cells are grown on a Murashige and Skoog (MS) medium supplemented with 0.1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg/L kinetin and solidified with 0.9% (w/v) agar, pH 5.8. Our Ak-1 cell culture has been maintained in the dark at 25–27°C and subcultured at 28-day intervals.

Materials

Chemicals and stock solutions

(All stock solutions are stored at 4°C)
  • MS salt mix

    Murashige and Skoog Plant Salt Mixture, Wako Pure Chemical Industries (#392-00591)

  • Sucrose

  • MS_VT

    Chemical Concentration (mg/mL)
    Nicotinic acid 0.5
    Pyridoxine·HCl 0.5
    Thiamine·HCl 0.1
    Glycine 2
  • MS_inositol

    Chemical Concentration (mg/mL)
    myo-Inositol 40
  • 2,4-D (0.2 mg/mL)

    Chemical Concentration (mg/mL)
    2,4-D sodium monohydrate 0.236

    (2,4-Dichlorophenoxy)acetic acid sodium salt monohydrate, Sigma-Aldrich (D6679)

  • Kinetin (0.2 mg/mL)

    Chemical Concentration (mg/mL)
    Kinetin 0.2

    Dissolve kinetin in small volume of KOH (1 N), and fill up with distilled water

  • Agar, powder

  • KOH (1 N)

Glassware and equipment

  • Erlenmeyer flask (100 mL), capped with two layers of aluminum foil
  • Forceps, sterilized before use

Preparation of MS medium (medium no. 50)

  1. Dissolve the following chemicals in approximately 800 mL of distilled water.

    Chemical Amount
    MS salt mix 1 bag (1 L)
    Sucrose 30 g
  2. Add following stock solutions, and fill up to approximately 950 mL with distilled water.

    Stock solution Volume (mL)
    MS_VT 1
    MS_inositol 2.5
    2,4-D (0.2 mg/mL) 0.5
    Kinetin (0.2 mg/mL) 5
  3. Adjust the pH of the solution to 5.8 with KOH (1 N), and fill up to 1 L with distilled water.

  4. Pour 40 mL of the medium into a 100-mL flask containing 0.36 g of agar.

  5. Autoclave the flask at 121°C for 20 min.

Methods

  1. Pick up an appropriate amount of callus cells from a 28-day-old culture with a forceps and place the cells onto fresh MS medium.
  2. Incubate cell cultures under the dark condition at 25–27°C.

Notes

  • We send Ak-1 cells on semi-solid MS medium in a 9-cm plastic Petri dish. The cells should be subcultured to fresh MS medium immediately after arrival.
  • In order to maintain Ak-1 callus culture stably, it is essential to observe the growth of cells carefully. Because proliferation of Ak-1 cells is affected by culture conditions, such as a room temperature, aeration conditions of the culture and so on, an amount of cells transferred to fresh medium and the subculture intervals may vary from one lab to another. We usually inoculate three to four pieces of Ak-1 callus (about 3–5-mm in diameter) on 40 mL of MS medium in a 100-mL flask, and culture them for 28 days.

Maintenance history

References

[1]Nakamura K, Akashi T, Aoki T, Kawaguchi K, Ayabe S (1999) Induction of isoflavonoid and retrochalcone branches of the flavonoid pathway in cultured Glycyrrhiza echinata cells treated with yeast extract. Bioscience, Biotechnology, and Biochemistry 63: 1618-1620. DOI: 10.1271/bbb.63.1618