| 摘要: |
| 【目的】马铃薯晚疫病是一种毁灭性病害，严重威胁马铃薯产业的健康发展。挖掘马铃薯抗病基因并解析其抗病机制，为马铃薯抗晚疫病育种提供理论依据。【方法】采用生物信息学方法鉴定和分析StGBF3转录因子的基本理化性质、蛋白结构、顺式作用元件和结构域，预测其跨膜结构及信号肽，并借助农杆菌介导法使StGBF3在马铃薯品种‘大西洋’叶片瞬时过表达，分析StGBF3转录因子在调控马铃薯抵抗晚疫病菌侵染过程中的功能及其作用机理。【结果】StGBF3共编码413个氨基酸，其中丝氨酸占比最高，为11.1%；半胱氨酸占比最低，仅为0.2%。StGBF3蛋白理论等电点为9.07，属于碱性蛋白；脂肪系数为58.62，平均亲水性为-0.794，为亲水性蛋白；分子质量44 511.45 ku。StGBF3与SlGBF3的序列相似性高达92.5%，StGBF3无跨膜结构和信号肽，在启动子区域存在多种响应逆境和防御相关的顺式作用元件。二级和三级结构分析结果表明，StGBF3蛋白α-螺旋有123个氨基酸，β-转角有16个氨基酸，无规则卷曲有259个氨基酸，延伸链有15个氨基酸，占比分别为29.78%，3.87%，62.71%和3.63%。与对照组（25 ℃）相比，4 ℃低温处理后‘大西洋’叶片中StGBF3的表达量在72 h达到最大值，是对照组的3.45倍；与喷施纯净水（RO）相比，喷施0.5 mmol/L水杨酸处理马铃薯品种‘大西洋’叶片中StGBF3分别在48和72 h分别显著提高2.57倍和2.87倍；而喷施1 mmol/L水杨酸与RO处理无显著差异。与对照组（CK）相比，晚疫病菌侵染后瞬时超表达StGBF3（OE）的‘大西洋’叶片中StGBF3的表达量在48 h达到最大值。相同处理时间下，CK组叶片发病面积大于OE，且台盼蓝染色结果显示CK死亡细胞数量大于OE。此外，随着处理时间的延长，OE叶片中病原菌相关分子模式激发的免疫（PTI）标记基因（ACER31、WRKY7、WRKY8）的表达量均呈先上升后下降趋势，且在处理48 h时达最大值；水杨酸SA（PR2、ChtA）、茉莉酸JA（PAL2）和乙烯ET（ERF3）信号通路的标记基因表达量在OE叶片中呈不同程度上调，且SA标记基因（PR2、ChtA）的表达量在处理48 h达到最大值，JA（PAL2）在处理72 h达到最大值，ET（ERF3）表达量呈先上升后下降趋势，但差异不显著。【结论】StGBF3通过激活SA和JA信号通路调控马铃薯对晚疫病的抗性。 |
| 关键词: 马铃薯晚疫病 GBF3转录因子 激素信号 基因表达 抗病机制 |
| DOI：10.13207/j.cnki.jnwafu.2025.12.012 |
| 分类号: |
| 基金项目:国家自然科学基金项目（32360465，32260455，32060441，32201810，32360488）；国家现代农业产业技术体系项目（CARS-09-P14） |
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| Bioinformatics analysis of StGBF3 and its modulation of potato late blight resistance |
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MA Yifan1, ZHANG Ruyan1, WANG Yong1, KANG Yichen1, LIU Yuhui2, QIN Shuhao1, ZHANG Weina1
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1.College of Horticulture,Gansu Agricultural University,Lanzhou,Gansu 730070,China;2.State Key Laboratory of Arid land Crop Science,Lanzhou,Gansu 730070,China
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| Abstract: |
| 【Objective】Potato late blight is a devastating disease that seriously threatens global potato production.This study aimed to identify disease resistance genes in potato and analyze their disease resistance mechanisms,thereby providing a theoretical basis for late-blight-resistant potato breeding.【Method】Bioinformatics methods were employed to identify and analyze the StGBF3 transcription factor,including its basic physicochemical properties,protein structure,cis-acting elements,domains,predicted transmembrane structure and signal peptide.Transient overexpression of StGBF3 in leaves of potato cultivar ‘Atlantic’ was accomplished via Agrobacterium-mediated transformation.Subsequent analysis elucidated the function and mechanisms of the StGBF3 transcription factor in regulating the resistance of potato to late blight infection.【Result】StGBF3 encoded 413 amino acids,with serine accounting for the highest proportion of 11.1%,and cysteine accounting for the lowest proportion of 0.2%.The theoretical isoelectric point of StGBF3 protein was 9.07,classifying it as an alkaline protein.With the fat coefficient of 58.62,the average hydrophilicity was -0.794,categorized as a hydrophilic protein.The relative molecular mass of StGBF3 was 44 511.45 ku.The sequence similarity between StGBF3 and SlGBF3 reached up to 92.5% without transmembrane structure and signal peptide.In the promoter region of SlGBF3,there were multiple cis-acting elements related to adversity response and stress defense.The results of the secondary and tertiary structure analysis revealed that StGBF3 protein had 123 amino acids in α-helix,16 amino acids in β-turn,259 amino acids in random coil,and 15 amino acids in extended strand,with proportions of 29.78%,3.87%,62.71%,and 3.63%,respectively.Compared with the control group (CK),StGBF3 expression in ‘Atlantic’ leaves under 4 ℃ low-temperature treatment reached the maximum at 72 h,which was 3.45 times that of CK at 25 ℃.Foliar spraying with 0.5 mmol/L salicylic acid (SA) significantly increased StGBF3 expression by 2.57 times and 2.87 times at 48 and 72 h,respectively,compared to treatment with reverse osmosis water (RO).No significant difference was observed between 1 mmol/L SA treatment and RO treatment.Following Phytophthora infestans inoculation,in the transient overexpression of StGBF3 (OE),the expression level of StGBF3 in leaves of potato cultivar ‘Atlantic’ reached the maximum at 48 h compared to CK.For the same treatment duration,the leaf disease area in CK was larger than that in OE.Trypan blue staining revealed that the number of dead cells in CK was larger compared to OE.In addition,as the treatment duration prolonged,the expression of pathogen-associated molecular pattern triggered immunity (PTI) marker genes (ACER31,WRKY7,and WRKY8) in OE leaves showed a trend of initially increasing and subsequently decreasing peaking at 48 h.The expression of marker genes of salicylic acid SA (PR2,ChtA),jasmonic acid JA (PAL2),and ethylene ET (ERF3) signaling pathways were up-regulated to different degrees in OE leaves.Specifically,the expression of SA marker genes (PR2,ChtA) reached peaked expression at 48 h,JA (PAL2) reached the maximum at 72 h,while the expression of ET (ERF3) increased initially and then decreased without statistically significant difference.【Conclusion】StGBF3 enhances late blight resistance in potato through activation of SA and JA signaling pathways. |
| Key words: potato late blight GBF3 transcription factor hormone signaling gene expression disease resistance mechanism |
