The Salicylic Acid Responsive UrSTR4 Gene is Involved in Rhynchophylline Biosynthesis in Uncaria rhynchophylla

doi:10.7525/j.issn.1673-5102.2025.04.003

Abstract

Abstract:

Uncaria rhynchophylla is a traditional Chinese medicinal herb， whose active components rhynchophylline（RIN） and isorhynchophylline（IRN） exhibit remarkable pharmacological activities. Strictosidine synthase（STR） is the key enzyme for RIN and IRN biosynthesis， yet the functional divergence of STR gene family in U. rhynchophylla remains unclear. Utilizing transcriptome data of U. rhynchophylla seedlings under shading and ethylene treatments， 27 STR genes（UrSTR1-UrSTR27） were systematically identified in U. rhynchophylla. Evolutionary analysis revealed significant expansion of UrSTR gene family， suggesting functional diversification in response to environmental cues. Exogenous salicylic acid（SA） treatment（0.6 mmol⋅L^-1） markedly increased RIN and IRN contents， while upregulating UrSTR4 expression level by 30.6-fold. Multiple sequence alignment showed UrSTR4 lacked the conserved Glu-309 residue but shared hydroxyl-containing residues with Camptotheca STR3. An efficient transient transformation system（8 kPa pressure， 1-min Agrobacterium infection） was established by using plant living transformation instrument. The transient overexpression of UrSTR4 enhanced RIN and IRN contents by 1.96- and 1.82-fold， respectively. This study identified new targets for metabolic regulation of bioactive compounds in U. rhynchophylla and the established transient transformation system provided technical support for functional research on UrSTR genes.

Key words: Uncaria rhynchophylla, strictosidine synthase, salicylic acid, transient transformation, monoter-penoid indole alkaloids

CLC Number:

Q946

Guoju XU, Piaoxue GUO, Xunran ZHU, Zimei YANG, Huanyu CHENG, Wei QIANG. The Salicylic Acid Responsive UrSTR4 Gene is Involved in Rhynchophylline Biosynthesis in Uncaria rhynchophylla[J]. Bulletin of Botanical Research, 2025, 45(4): 491-503.

Figures/Tables 7

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References 30

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引物名称 Primer name	引物序列（5′—3′） Primer sequence（5′—3′）	引物名称 Primer name	引物序列（5′—3′） Primer sequence（5′—3′）
F-STR4-OE	cacgggggactcttgggatccGCAATGACGCTGACCGGAT	R-STR4-OE	cgatcggggaaattcgagctcTAGGGAACTATTTTGTCACTCTAATTGG
Fq-GAPDH	AGCAAGGACTGGAGAGGTGGAAG	Rq-GAPDH	CCGTTGAGGGCTGGAAGAACTTTC
Fq-STR1	CTCCGCCATATAAAGGTG	Rq-STR1	GACAGAAGAAGCCAATCC
Fq-STR2	GGTAACAACTCCGAACAG	Rq-STR2	CACCATTAGGACCAACTAC
Fq-STR3	CCTCCTTACAGTGACTTC	Rq-STR3	GTCCATCAGAACCGTTAC
Fq-STR4	CAAGGACCTTATGCGAGCGTCTC	Rq-STR4	TTGGTCCAAGGTCGGGATTTGTTG
Fq-STR5	CATCCCTCTACCGTATAAAG	Rq-STR5	GAAGAAGCCTCTCCATTC
Fq-STR6	GATGGTCGGATTCTCAAG	Rq-STR6	GATGAACACACTCCTTCC
Fq-STR7	CTTCTTCTCCTCATCTTCG	Rq-STR7	GACAACTCTGCCATCTTC
Fq-STR8	GGTTCAAGACATCCTGAG	Rq-STR8	GCCATCTCTGCTAACTTC
Fq-STR9	CTCTCTCATCCTCCTCAA	Rq-STR9	GTAGACCACAACTGCTAG

基因名称 Gene name	氨基酸残基 Amino acid residues/aa	相对分子质量 Molecular weight/Da	不稳定系数 Instability index	等电点 Isoelectric point/pI	亲水性 Hydrophilicity	脂肪指数 Aliphatic index
UrSTR1	359	39 757.77	26.91	5.44	-0.196	82.79
UrSTR2	340	37 332.35	32.45	7.71	-0.244	82.26
UrSTR3	419	42 301.06	33.62	6.92	-0.254	86.18
UrSTR4	391	43 858.54	38.06	7.59	-0.179	87.77
UrSTR5	345	37 974.68	25.40	5.49	-0.186	85.30
UrSTR6	301	33 662.11	34.82	7.82	0.034	101.99
UrSTR7	353	38 959.17	31.16	5.22	-0.119	86.69
UrSTR8	345	37 957.65	26.18	5.28	-0.184	87.28
UrSTR9	397	44 083.25	28.70	5.77	-0.151	92.54
UrSTR10	341	36 791.16	28.91	5.71	0.085	99.18
UrSTR11	296	32 642.00	34.72	6.52	-0.165	84.59
UrSTR12	191	20 798.44	20.61	4.53	0.017	95.39
UrSTR13	64	7 234.31	38.38	8.55	-0.331	63.75
UrSTR14	341	36 791.16	28.91	5.71	0.085	99.18
UrSTR15	175	20 227.28	27.83	9.34	-0.341	86.86
UrSTR16	175	20 237.32	27.40	9.38	-0.346	86.86
UrSTR17	187	20 584.27	17.69	5.85	-0.234	92.73
UrSTR18	175	20 295.36	27.40	9.25	-0.376	86.29
UrSTR19	140	15 445.99	27.56	10.01	-0.013	93.36
UrSTR20	52	5 639.56	15.13	9.82	-0.073	97.31
UrSTR21	81	8 790.11	11.97	10.11	-0.200	90.12
UrSTR22	80	8 852.30	26.24	9.58	-0.129	97.37
UrSTR23	177	19 459.11	22.71	6.29	-0.160	94.63
UrSTR24	153	16 949.43	19.75	9.68	-0.186	88.43
UrSTR25	66	7 253.40	22.19	9.99	-0.255	88.48
UrSTR26	256	27 801.75	30.32	5.16	-0.054	92.85
UrSTR27	381	42 185.94	26.32	5.32	0.257	107.43