Cloning， expression profiling and DNA variation analysis of the disease-resistance gene CqSGT1 in quinoa （Chenopodium quinoa）

doi:10.11686/cyxb2025063

Abstract

Abstract:

The growth and development of quinoa （Chenopodium quinoa） are negatively affected by adverse conditions， and that restricts the development of the quinoa industry. SGT1 （suppressor of the G2 allele of Skp1） participates in the plant stress resistance response by regulating molecular chaperones and ubiquitination. The SGT1 protein inhibits Skp1-4， which are components of ubiquitin ligase complexes that regulating biological processes such as the cell cycle， signal transduction， and gene expression. The aim of this study was to identify quinoa SGT1 genes and determine their transcriptional responses to biotic and abiotic stress conditions. The SGT1 genes of quinoa were identified using bioinformatics-based methods， and their sequence characteristics， phylogenetic relationships， and expression patterns were analyzed. In addition， the physical and chemical properties and protein interaction networks of their putative encoded proteins were determined. The quinoa genome was found to contain two SGT1 genes， CqSGT1a and CqSGT1b， located on chromosomes 6 and 7. The putative quinoa SGT1 proteins are rich in basic amino acids， lack signal peptides， and are dominated by α-helixes. They were predicted to localize to the nucleus. Both were predicted to be hydrophobic proteins without transmembrane structures， and both contained the characteristic TPR-SGS-CS domain. The CqSGT1 promoter regions contained cis-acting elements related to light and hormone responsiveness， suggesting that the expression of these genes is tightly regulated during growth， development， and stress responses. The CqSGT1 genes showed the closest relationship with BvSGT1 from Beta vulgaris. The results of qPCR analyses showed that the highest transcript levels of SGT1 in quinoa were in the flowers and grains， suggesting that their expression was related to the formation and development of these organs. Under low temperature stress， both SGT1 genes were initially up-regulated and then down-regulated. Treatment with salicylic acid induced the expression of SGT1， and the response was most significant at 3 h after inoculation. SGT1 responses were seen during downy mildew （Peronospora variabilis） infection in the resistant quinoa line 2403. In the resistant line， SGT1 transcript levels were significantly increased at 2 h after inoculation， then decreased， and then subsequently increased again. The strongest response was at 24 h， indicating that the SGT1a/b genes play a positive regulatory role in the response to quinoa downy mildew. Both CqSGT1 genes showed tissue-specific expression patterns and responded to low temperature， salicylic acid， and downy mildew infection. These results show that SGT1 plays an important role in the growth and development of quinoa， and in its responses to biotic and abiotic stress.

Key words: Chenopodium quinoa, SGT1, Peronospora variabilis, bioinformatics analysis, gene cloning

Miao-miao DOU, Xiao-dong JIANG, Hui-qiong SUN, Hong-shen XU, Xi-liang WANG, Bo-hui YANG, Wen-ting CHAI, Shan-shan ZHAO, Chun-lai ZHANG. Cloning， expression profiling and DNA variation analysis of the disease-resistance gene CqSGT1 in quinoa （Chenopodium quinoa）[J]. Acta Prataculturae Sinica, 2026, 35(1): 223-240.

Figures/Tables 18

References 44

[1]	Gómez-Caravaca A M， Iafelice G， Verardo V， et al. Influence of pearling process on phenolic and saponin content in quinoa （Chenopodium quinoa Willd）. Food Chemistry， 2014， 15（157）： 174-178.
[2]	Jiang X D， Li X F， Hao Y P， et al. Gene cloning and express of squalene synthase and β-amyrin synthase from Chenopodium quinoa. Soils， 2018， 50（6）： 1214-1221.
	姜晓东，李新凤，郝艳平，等. 藜麦β-香树酯醇合酶和鲨烯合酶基因的克隆与表达. 土壤， 2018， 50（6）： 1214-1221.
[3]	Jarvis D E， Ho Y S， Lightfoot D J， et al. The genome of Chenopodium quinoa. Nature， 2017， 542（7641）： 307-312.
[4]	Bazile D， Fuentes F， Mujica A. Historical perspectives and domestication//Bhargava A. Quinoa： botany， production and uses. Wallingford： Centre for Agriculture and Bioscience International， 2013： 16-35.
[5]	Hinojosa L， González J A， Barrios-Masias F H， et al. Quinoa abiotic stress responses： a review. Plants， 2018， 7（4）： 106.
[6]	Wang C. Study on resistance evaluation of quinoa germplasms to downy mildew and its resistance mechanisms. Lanzhou： Gansu Agricultural University， 2023.
	王昶. 藜麦种质对霜霉病的抗性评价及其抗病机理研究. 兰州：甘肃农业大学， 2023.
[7]	Wang C， Li M Q， Yang F R， et al. Diseases investigation and pathogen identification of quinoa downy mildew in Gansu Province. Journal of Nuclear Agriculture， 2023（3）： 503-512.
	王昶，李敏权，杨发荣，等. 甘肃藜麦霜霉病调查及其病原菌鉴定. 核农学报， 2023（3）： 503-512.
[8]	Yuan C L， Li C J， Zhao X B， et al. Genome-wide identification and characterization of HSP90-RAR1-SGT1-Complex members from Arachis genomes and their responses to biotic and abiotic stresses. Frontiers in Genetics， 2021， 12： 689669.
[9]	Kitagawa K， Skowyra D， Elledge S J， et al. SGT1 encodes an essential component of the yeast kinetochore assembly pathway and a novel subunit of the SCF ubiquitin ligase complex. Molecular Cell， 1999， 4（1）： 21-33.
[10]	Wang K， Zhang Z Y. Progress in studying the function of SGT1 in plant disease resistance response. Journal of Plant Genetic Resources， 2008， 9（1）： 115-118.
	王凯，张增燕. SGT1在植物抗病反应中的功能研究进展. 植物遗传资源学报， 2008， 9（1）： 115-118.
[11]	Zhang D L， Yang X X， Wen Z Y， et al.Proxitome profiling reveals a conserved SGT1-NSL1 signaling module that activates NLR-mediated immunity. Molecular Plant， 2024， 17（9）： 1369-1391.
[12]	Azevedo C， Sadanandom A， Kitagawa K， et al. The RAR1 interactor SGT1， an essential component of R gene-triggered disease resistance. Science， 2002， 295（5562）： 2073-2076.
[13]	Wang K， Uppalapati S R， Zhu X H， et al. SGT1 positively regulates the process of plant cell death during both compatible and incompatible plant-pathogen interactions. Molecular Plant Pathology， 2010， 11（5）： 597-611.
[14]	Makoto I， Ohnishi K， Hikichi Y， et al. Molecular chaperons and co-chaperons， Hsp90， RAR1， and SGT1 negatively regulate bacterial wilt disease caused by Ralstonia solanacearum in Nicotiana benthamiana. Plant Signaling & Behavior， 2015， 10： e970410.
[15]	Kumar D， Kirt P B. Pathogen-induced SGT1of Arachis diogoi induces cell death and enhanced disease resistance in tobacco and peanut. Plant Biotechnology Journal， 2015， 13： 73-84.
[16]	Yu G， Xian L， Zhuang H Y， et al. SGT1 is not required for plant LRR-RLK-mediated immunity. Molecular Plant Pathology， 2021， 22（1）： 145-150.
[17]	Chen Z Q， Wu Q， Tong C， et al. Characterization of the roles of SGT1/RAR1， EDS1/NDR1， NPR1， and NRC/ADR1/NRG1 in Sw-5b-mediated resistance to tomato spotted wilt virus. Viruses， 2021， 13（8）： 1447.
[18]	Shanmugam A， Thamilarasan S K， Park J I， et al. Characterization and abiotic stress-responsive expression analysis of SGT1 genes in Brassica oleracea. Genome， 2016， 59： 243-251.
[19]	Berens M L， Berry H M， Mine A， et al. Evolution of hormone signaling networks in plant defense. Annual Review of Phytopathology， 2017， 55（1）： 401-425.
[20]	Váczy K Z， Otto M， Gomba-Tóth A， et al. Botrytis cinerea causes different plant responses in grape （Vitis vinifera） berries during noble and grey rot： diverse metabolism versus simple defence. Frontiers in Plant Science， 2024， 15： 1433161.
[21]	Yu G， Xian L， Xue H， et al. A bacterial effector protein prevents MAPK-mediated phosphorylation of SGT1to suppress plant immunity. PLoS Pathogens， 2020， 16（9）： e1008933.
[22]	Peart J R， Lu R， Sadanandom A， et al. Ubiquitin ligase-associated protein SGT1 is required for host and nonhost disease resistance in plants. Proceedings of the National Academy of Sciences of the United States of America， 2002， 99（16）： 10865-10869.
[23]	Zhu X D， Yang L F， Chen Y Y， et al. Biological functional analysis of common buckwheat （Fagopyrum esculentum） FeSGT1 gene in enhancing drought stress resistance. Acta Agronomica Sinica， 2023， 49（6）： 1573-1583.
	朱旭东，杨兰锋，陈媛媛，等. 甜荞FeSGT1基因克隆及抗旱功能解析. 作物学报， 2023， 49（6）： 1573-1583.
[24]	Agarwal G， Garg V， Kudapa H， et al. Genome-wide dissection of AP2/ERF and HSP90 gene families in five legumes and expression profiles in chickpea and pigeonpea. Plant Biotechnology Journal， 2016， 14： 1563-1577.
[25]	Zou C S， Chen A J， Xiao L H， et al. A high-quality genome assembly of quinoa provides insights into the molecular basis of salt bladder-based salinity tolerance and the exceptional nutritional value. Cell Research， 2017， 27（11）： 1327-1340.
[26]	Xie Y J， Xue J， Jiang X D， et al. Screening of reference genes in Chenopodium quinoa under Peronospora variabilis stress and verification of their stability. Journal of Fujian Agriculture and Forestry University （Natural Science Edition）， 2024， 53（2）： 191-198.
	解宇洁，薛婧，姜晓东，等. 霜霉病菌胁迫下藜麦内参基因的筛选及其稳定性验证. 福建农林大学（自然科学版）， 2024， 53（2）： 191-198.
[27]	Koua A P， Oyiga B C， Baig M M， et al. Breeding driven enrichment of genetic variation for key yield components and grain starch content under drought stress in winter wheat. Frontiers in Plant Science， 2021， 12： 684205.
[28]	Meldau S， Baldwin I T， Wu J Q. For security and stability： SGT1 in plant defense and development. Plant Signaling & Behavior， 2011， 6（10）： 1479-1482.
[29]	Holt B F， Belkhadir Y， Dangl J L. Antagonistic control of disease resistance protein stability in the plant immune system. Science， 2005， 309（5736）： 929-932.
[30]	Muskett P， Parker J. Role of SGT1 in the regulation of plant R gene signaling. Microbes and Infection， 2003， 5（11）： 969-976.
[31]	Chen X Y， Li X B， Duan Y H， et al. A secreted fungal subtilase interferes with rice immunity via degradation of suppressor of G2 allele of skp1. Plant Physiology， 2022， 190（2）： 1474-1489.
[32]	Wang Y Q， Liu C， Du Y Y， et al. A stripe rust fungal effector PstSIE1 targets TaSGT1 to facilitate pathogen infection. The Plant Journal， 2022， 112（6）： 1413-1428.
[33]	Steven S R， Huang L， Brandt A S， et al. Development of a virus-induced gene-silencing system for hexaploid wheat and its use in functional analysis of the Lr21-mediated leaf rust resistance pathway. Plant Physiology， 2005， 138（4）： 2165-2173.
[34]	Li X B. Functional characterization of subtilisin-like protease family genes in Ustilaginoidea virens. Changsha： Central China Agricultural University， 2022.
	李夏冰. 稻曲菌枯草杆菌蛋白酶家族基因功能研究. 长沙：华中农业大学， 2022.
[35]	Ouyang X， Chen J L， Sun Z M， et al. Ubiquitin E3 ligase activity of Ralstonia solanacearum effector RipAW is not essential for induction of plant defense in Nicotiana benthamiana. Frontiers in Microbiology， 2023， 14： 1201444.
[36]	Zhang C L， Xu D C， Jiang X C. Improvement of disease resistance of sugar beet by molecular breeding. China Beet & Sugar， 2008（2）： 23-26.
	张春来，徐德昌，姜孝成. 分子育种提高甜菜抗病性. 中国甜菜糖业， 2008（2）： 23-26.
[37]	Guo W L， Chen B H， Guo Y Y， et al. Improved powdery mildew resistance of transgenic Nicotiana benthamiana overexpressing the Cucurbita moschata CmSGT1 gene. Frontiers in Plant Science， 2019， 10： 955.
[38]	Forner-Giner M Á， Rodríguez-Gamir J， Primo-Millo E， et al. Hydraulic and chemical responses of citrus seedlings to drought and osmotic stress. Journal of Plant Growth Regulation， 2011， 30（3）： 353-366.
[39]	Luna C M， Pastori G M， Driscoll S， et al. Drought controls on H₂O₂ accumulation， catalase （CAT） activity and CAT gene expression in wheat. Journal of Experimental Botany， 2005， 56（411）： 417-423.
[40]	Baczek-Kwinta R， Filek W， Grzesiak S， et al. The effect of soil drought and rehydration on growth and antioxidative activity in flag leaves of triticale. Biologia Plantarum， 2006， 50（1）： 55-60.
[41]	Mhamdi A， Queval G， Chaouch S， et al. Catalase function in plants： a focus on Arabidopsis mutants as stress-mimic models. Journal of Experimental Botany， 2010， 61（15）： 4197-4220.
[42]	Jiang J M， Chen J T， Luo L， et al. Expression analysis reveals that sorghum disease resistance protein SbSGT1 is regulated by auxin. Biology， 2022， 11（1）： 67.
[43]	Li R Q， Zheng W Y， Yang R F， et al. OsSGT1promotes melatonin-ameliorated seed tolerance to chromium stress by affecting the OsABI5-OsAPX1 transcriptional module in rice. The Plant Journal， 2022， 112（1）： 151-171.
[44]	Noël L D， Cagna G， Stuttmann J， et al. Interaction between SGT1 and cytosolic/nuclear HSC70 chaperons regulates Arabidopsis immune responses. Plant Cell， 2007， 19（12）： 4061-4076.

基因名称 Gene name	正向序列 Forward primer （5′→3′）	反向序列 Reverse primer （5′→3′）	用途 Application
CqSGT1a	ACGGAAAGGAACTGCGTGTA	GGCTGCTTGTGCATTGGTAG	qRT-PCR， SemiRT-PCR
CqSGT1b	TTACCTACGAAAAGGGACCGC	TGCTTGTGCATTGGTAGGCT	qRT-PCR， SemiRT-PCR
CqEF1α	GACAAGCGTGTGATCGAGAG	TCGGCCTTAAGTTTGTCGAG	qRT-PCR， SemiRT-PCR
TI-CqSGT1a/b	ATGGCGACGGATCTCGAGACCAAG	TTAGTATTCCCATTTCTTCATCTC	基因克隆Gene clone
pCAMBIA1300-Cq SGT1a/b	CGCGGATCCAATGGCGACGGATCTCGAGACCAAG	CGCGTCGACTTAGTATTCCCATTT CTTCATCTC	瞬时表达Transient expression
M13	GTTGTAAAACGACGGCCAG	CAGGAAACAGCTATGAC	基因克隆和瞬时表达Gene clone and transient expression

基因名称 Gene name	正向序列 Forward primer （5′→3′）	反向序列 Reverse primer （5′→3′）	用途 Application
CqSGT1a	ACGGAAAGGAACTGCGTGTA	GGCTGCTTGTGCATTGGTAG	qRT-PCR， SemiRT-PCR
CqSGT1b	TTACCTACGAAAAGGGACCGC	TGCTTGTGCATTGGTAGGCT	qRT-PCR， SemiRT-PCR
CqEF1α	GACAAGCGTGTGATCGAGAG	TCGGCCTTAAGTTTGTCGAG	qRT-PCR， SemiRT-PCR
TI-CqSGT1a/b	ATGGCGACGGATCTCGAGACCAAG	TTAGTATTCCCATTTCTTCATCTC	基因克隆Gene clone
pCAMBIA1300-Cq SGT1a/b	CGCGGATCCAATGGCGACGGATCTCGAGACCAAG	CGCGTCGACTTAGTATTCCCATTT CTTCATCTC	瞬时表达Transient expression
M13	GTTGTAAAACGACGGCCAG	CAGGAAACAGCTATGAC	基因克隆和瞬时表达Gene clone and transient expression

元件名称 Element name	核心序列 Core sequence	元件功能 Element function	数量Quantity
元件名称 Element name	核心序列 Core sequence	元件功能 Element function	CqSGT1a	CqSGT1b
chs-CMA1a	TTACTTAA	部分光响应元件Part of light responsive element	1	-
3-AF1 binding site	TAAGAGAGGAA	光响应元件Light responsive element	1	-
HD-Zip 3	GTAAT（G/C）ATTAC	蛋白质结合位点Protein binding site	1	-
ARE	AAACCA	厌氧诱导必不可少的顺式作用调节元件Cis-acting regulatory element essential for the anaerobic induction	4	1
GT1-motif	GGTTAA	光响应元件Light responsive element	2	-
Box 4	ATTAAT	参与光响应的部分保守DNA模块Part of conserved DNA module involved in light responsiveness	3	4
G-box	CACGAC	参与光反应的顺式作用调节元件Cis-acting regulatory element involved in light responsiveness	1	-
GA-motif	ATAGATAA	部分光响应元件Part of light responsive element	1	-
TCT-motif	TCTTAC	部分光响应元件Part of light responsive element	1	-
P-box	CCTTTTG	赤霉素响应元件Gibberellin-responsive element	2	2
Gap-box	CAAATGAA（A/G）A	光响应元件Light responsive element	1	-
TCA-element	CCATCTTTTT	参与水杨酸反应的顺式作用调节件Cis-acting element involved in salicylic acid responsiveness	1	-
ATCT-motif	AATCTAATCC	参与光响应的部分保守DNA模块Part of conserved DNA module involved in light responsiveness	1	-
TATA-box	AATCTAATCC	转录起始-30核心启动子元件Core promoter element around-30 of transcription start	64	53
MBSI	AAAAAAC（G/C）GTTA	MYB结合位点参与类黄酮生物合成基因的调控元件MYB-binding site as a regulatory element involved in the control of flavonoid biosynthetic genes	-	1
CAAT-box	CAAAT	启动子和增强子区域调控元件Promoter and enhancer region regulatory elements	-	12
TCT-motif	TCTTAC	部分光响应元件Part of light responsive element	-	2
O₂-site	GTTGACGTGA	参与玉米醇溶蛋白代谢调控的顺式调节元件Cis-acting regulatory element involved in zein metabolism regulation	-	1
MRE	AACCTAA	MYB结合位点（参与光响应）MYB binding site involved in light responsiveness	-	1
Circadian	AACCTAA	参与昼夜节律控制的顺式作用调节元件Cis-acting regulatory element involved in circadian control	-	1

元件名称 Element name	核心序列 Core sequence	元件功能 Element function	数量Quantity
元件名称 Element name	核心序列 Core sequence	元件功能 Element function	CqSGT1a	CqSGT1b
chs-CMA1a	TTACTTAA	部分光响应元件Part of light responsive element	1	-
3-AF1 binding site	TAAGAGAGGAA	光响应元件Light responsive element	1	-
HD-Zip 3	GTAAT（G/C）ATTAC	蛋白质结合位点Protein binding site	1	-
ARE	AAACCA	厌氧诱导必不可少的顺式作用调节元件Cis-acting regulatory element essential for the anaerobic induction	4	1
GT1-motif	GGTTAA	光响应元件Light responsive element	2	-
Box 4	ATTAAT	参与光响应的部分保守DNA模块Part of conserved DNA module involved in light responsiveness	3	4
G-box	CACGAC	参与光反应的顺式作用调节元件Cis-acting regulatory element involved in light responsiveness	1	-
GA-motif	ATAGATAA	部分光响应元件Part of light responsive element	1	-
TCT-motif	TCTTAC	部分光响应元件Part of light responsive element	1	-
P-box	CCTTTTG	赤霉素响应元件Gibberellin-responsive element	2	2
Gap-box	CAAATGAA（A/G）A	光响应元件Light responsive element	1	-
TCA-element	CCATCTTTTT	参与水杨酸反应的顺式作用调节件Cis-acting element involved in salicylic acid responsiveness	1	-
ATCT-motif	AATCTAATCC	参与光响应的部分保守DNA模块Part of conserved DNA module involved in light responsiveness	1	-
TATA-box	AATCTAATCC	转录起始-30核心启动子元件Core promoter element around-30 of transcription start	64	53
MBSI	AAAAAAC（G/C）GTTA	MYB结合位点参与类黄酮生物合成基因的调控元件MYB-binding site as a regulatory element involved in the control of flavonoid biosynthetic genes	-	1
CAAT-box	CAAAT	启动子和增强子区域调控元件Promoter and enhancer region regulatory elements	-	12
TCT-motif	TCTTAC	部分光响应元件Part of light responsive element	-	2
O₂-site	GTTGACGTGA	参与玉米醇溶蛋白代谢调控的顺式调节元件Cis-acting regulatory element involved in zein metabolism regulation	-	1
MRE	AACCTAA	MYB结合位点（参与光响应）MYB binding site involved in light responsiveness	-	1
Circadian	AACCTAA	参与昼夜节律控制的顺式作用调节元件Cis-acting regulatory element involved in circadian control	-	1

基因 Gene	染色体位置Chromosome location	Ref	Alt	JQ3	JQ6	Qingheili-8	Qingbaili-9	影响Effect（其他突变系Other mutant lines）	改变的密码子 The changed codon
CqSGT1a	Chr06：34577463	GA	G	GA， GA	GA， GA	GA， GA	G，G	内含子Intron	GTa/Gat
CqSGT1b	Chr07：83675475	A	AT	N	A， AT	A， AT	N	上游Upstream	aAt/aAT
CqSGT1b	Chr07：83677523	A	AC	AC， AC	AC， AC	AC， AC	AC， AC	内含子Intron	aAc/aAC
CqSGT1b	Chr07：83679761	CA	C	C， C	C， C	C， C	CA， C	内含子Intron	cCA/cCa
CqSGT1b	Chr07：83679830	TTTGTTGTTGTTG	T	TTTGTTGTTGTTG， TTTGTTGTTGTTG	N	N	TTTGTTGTTGTTG， T	内含子Intron	cTTTGTTGTTGTTGT/cTt
CqSGT1b	Chr07：83689890	A	ATAGCTGGCACAAACGGTGCCTTGT	A， A	A， ATAGCTGGCACAAACGGTGCCTTGT	A， ATAGCTGGCACAAACGGTGCCTTGT	A， ATAGCTGGCA CAAACGGTGCCTTGT	下游Downstream	aAt/aATAGCTGGCACAAACGGTGCCTTGTt
CqSGT1b	Chr07：83690874	A	AT	AT， AT	A， A	A， A	N	下游Downstream	tAt/tAT
CqSGT1b	Chr07：83691319	G	GA	GA， GA	GA， GA	GA， GA	GA， GA	下游Downstream	acGaaa/acGAaa