Table 2.

Genetic engineering to increase artemisinin production in A. annua.

Gene Name	Expression Mode	Artemisinin (mg/g DW)		Fold Change	Reference
		Control	Transgenic
MVA or MEP pathway key genes
CrHMGR 1	Overexpression	0.32	0.39	1.22	[52]
		0.37	0.60	1.62	[35]
CrDXR 1	Overexpression	0.52	1.21	2.33	[36]
IPPI1	Overexpression	0.75	2.5	3.33	[38]
HDR1	Overexpression	0.05	0.09	1.8	[37]
HDR1	Down-regulation	0.05	0.03	0.6
GaFPPS 2	Overexpression	3	10.08	3.36	[42]
FPPS	Overexpression	6.5	0.9	1.38	[40]
		5.3	13.3	2.5	[41]
Artemisinin biosynthesis pathway key genes
ADS	Overexpression	0.6	1.2	2	[45]
DBR2	Overexpression	0.94	2.14	2.26	[46]
		8	22.6	2.83	[53]
ALDH1	Overexpression	8	25.6	3.2	[54]
HMGR, FPPS	Overexpression	5	9	1.8	[55]
HMGR, ADS	Overexpression	0.2	1.73	8.65	[47]
ADS-FPPS fusion	Overexpression	10	26	2.6	[48]
CYP71AV1, CPR	Overexpression	0.91	2.44	2.68	[36]
		0.71 (mg/g FW)	0.98 (mg/g FW)	1.38	[49]
FPPS, CYP71AV1, CPR	Overexpression	0.83 (mg/g FW)	2.98 (mg/g FW)	3.6	[50]
ADS, CYP71AV1, CPR	Overexpression	6.4	15.1	2.4	[56]
ADS, CYP71AV1, CPR, ALDH1	Overexpression	8	27	3.4	[51]
Competitive pathway key genes
SQS	Down-regulation	10	31.4	3.14	[57]
CPS	Down-regulation	2.32	3.6	1.55	[58]
CPS	Down-regulation	6.26	11.08	1.77	[59]
BFS	Down-regulation	6.26	11.08	1.77
GAS	Down-regulation	6.26	12.71	2.03
SQS	Down-regulation	6.26	10.70	1.71

¹CrHMGR and CrDXR genes were from C. roseus. ² GaFPPS gene was from Gossypium arboreum.