Zhou Xiaocheng, Yuan Jianlong, Cheng Lixiang, Xia Lulu, Tang Zhensan, Zhang Feng
State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, 730070, China.
BMC Plant Biol. 2025 May 29;25(1):725. doi: 10.1186/s12870-025-06766-6.
Steroidal glycoalkaloids (SGAs), derived from cholesterol, act as natural defenses against pathogens and pests. In cultivated potatoes, α-solanine and α-chaconine are the primary SGAs, distributed throughout the plant, with their biosynthesis mechanisms differing across various tissues. The variation in SGAs content between the cortex and perimedullary zone reflects tissue-specific metabolic regulation in potato tuber. Higher SGAs levels in the cortex may enhance defense against external threats. This spatial distribution provides a theoretical basis for breeding strategies aimed at balancing resistance and food quality by regulating SGAs accumulation in specific tissues of potato tubers. Excessive levels of SGAs in potato tubers can compromise both their quality and edibility. Additionally, SGAs exhibit pharmacological properties, including anti-protozoal, antibacterial, antiviral, anti-tumor, and anti-inflammatory effects.
This study conducted genome-wide association study (GWAS) on SGAs content in the cortex and perimedullary zone of 117 diverse potato germplasm accessions, utilizing 22,983,689 high-quality SNPs. Candidate genes were subjected to analyses of stability, pleiotropy, GO and KEGG enrichment, and haplotype profiling. Twelve candidate genes associated with SGAs biosynthesis in potato tubers were identified, encoding UDP-glycosyltransferase superfamily proteins (Soltu.DM.11G005750, Soltu.DM.11G005760, Soltu.DM.11G005770, Soltu.DM.11G005820), fatty acid hydroxylase superfamily proteins (Soltu.DM.01G029600, Soltu.DM.01G029610, Soltu.DM.01G029620, Soltu.DM.01G029640, Soltu.DM.01G029650, Soltu.DM.10G008360), alkaline/neutral invertase (Soltu.DM.11G006090), and pleiotropic drug resistance (Soltu.DM.11G006080).
This study provides a theoretical basis for elucidating the genetic mechanisms underlying SGAs biosynthesis in potatoes and will facilitate the breeding of new potato varieties.
甾体糖苷生物碱（SGAs）由胆固醇衍生而来，是植物抵御病原体和害虫的天然防御物质。在栽培马铃薯中，α-茄碱和α-查茄碱是主要的SGAs，分布于整个植株，其生物合成机制在不同组织中有所不同。皮层和髓周区之间SGAs含量的差异反映了马铃薯块茎中组织特异性的代谢调控。皮层中较高的SGAs水平可能增强对外部威胁的防御能力。这种空间分布为通过调节马铃薯块茎特定组织中SGAs的积累来平衡抗性和食品质量的育种策略提供了理论基础。马铃薯块茎中SGAs含量过高会影响其品质和可食性。此外，SGAs还具有药理特性，包括抗原生动物、抗菌、抗病毒、抗肿瘤和抗炎作用。
本研究利用22,983,689个高质量单核苷酸多态性（SNPs），对117份不同马铃薯种质资源的皮层和髓周区的SGAs含量进行了全基因组关联研究（GWAS）。对候选基因进行了稳定性、多效性、基因本体（GO）和京都基因与基因组百科全书（KEGG）富集分析以及单倍型分析。鉴定出12个与马铃薯块茎中SGAs生物合成相关的候选基因，它们分别编码尿苷二磷酸糖基转移酶超家族蛋白（Soltu.DM.11G005750、Soltu.DM.11G005760、Soltu.DM.11G005770、Soltu.DM.11G005820）、脂肪酸羟化酶超家族蛋白（Soltu.DM.01G029600、Soltu.DM.01G029610、Soltu.DM.01G029620、Soltu.DM.01G029640、Soltu.DM.01G029650、Soltu.DM.10G008360）、碱性/中性转化酶（Soltu.DM.11G006090）和多药耐药蛋白（Soltu.DM.11G006080）。
本研究为阐明马铃薯中SGAs生物合成的遗传机制提供了理论基础，并将促进马铃薯新品种的培育。
