. 2022 Dec 26;13(1):39. doi: 10.3390/metabo13010039

Table 4.

Hairy/adventitious root cultures for the production of AQs in Rubia species.

Species and Type of Root Cultures	Culture Medium	Growth Regulators, Additives, and Other Parameters	Metabolites and Yield or Productivity	References
Rubia cordifolia var. pratensis; hairy roots	NN	They tested the effect of auxins viz. 0.5, 1.0 mg L⁻¹ NAA, and 0.1 mg L⁻¹ IAA on the growth and accumulation of metabolites.	AQs—Not reported	[62]
Rubia peregrina; hairy roots	B5	Gamborg B5 medium containing 30 g L−1 sucrose, 10 g L⁻¹ agar	AQs—2.12 mg g⁻¹ DW	[63,64]
Rubia akane; hairy roots	MS	MS + 3% sucrose studied the accumulation of alizarin and purpurin	AQs—3.9 and 4.5 mg g⁻¹ DW alizarin and purpurin	[65]
Rubia akane; hairy roots	Various media	Studied the effect of half and full strength of B5, half and full strength of MS, and a half and full strength of SH media; 0.1, 0.5, 1.0 mg L⁻¹ IAA, IBA and NAA	AQs—5.9 and 7.2 mg g⁻¹ DW alizarin and purpurin	[66]
R. tinctorum; hairy roots	MS	Studied the effect of 0.5, 5 μM IAA, NAA or 2,4-D, and 0.5 μM KN; and 3,6, 9, 12, 15, and 18% sucrose on the growth of roots and AQs production	AQs—700 μg g⁻¹ FW	[67]
Rubia tinctorum; hairy roots	MS	Studied the effect of fructose galactose, glucose, lactose, maltose, and sucrose (2%); altered nitrogen (1.90 g L⁻¹ KNO₃ + 1.65 g L⁻¹ NH₄NO₃) and (6.07 g L⁻¹ KNO₃) on AQs accumulation	AQs—0.72 mg g⁻¹ day⁻¹	[68]
Rubia tinctorum; hairy roots;	1/2 B5	2% sucrose + 2 mg L⁻¹ 2,4-D + 0.5 mg L⁻¹ NAA, 0.5 mg L⁻¹ IAA and 0.5 mg L⁻¹ KN and cells were elicited by 100 μM MJ	AQs—33.4 μmol L−1 day⁻¹	[69]
Rubia tinctorum; adventitious roots	MS	Studied the effect of Methyl jasmonate (10 and 100 μM) and caffeic acid (1 and 2 mM) on the growth of roots and AQs	AQs—Not reported	[70]
Rubia tinctorum; adventitious roots	MS	MS +2% sucrose and studied the effect of L-phenylalanine (50 and 100 μM) and salicylic acid (20 and 40 μM) on the accumulation of AQs	AQs—31.47 mg g⁻¹ DW	[71]

¹ 2,4-D—2,4-dichlorophenoxyacetic acid; Gamborg B5 medium; IAA—indoleacetic acid; KN—kinetin; MJ—Methyl jasmonate; MS—Murashige and Skoog medium; NAA—1-naphthalene acetic acid; Nitsch and Nitsch medium [72]; SA—salicylic acid.