Comparative Metabolite Profiling of Solanum tuberosum against Six Wild Solanum Species with Colorado Potato Beetle Resistance

The Colorado potato beetle Leptinotarsa decemlineata (Say) (CPB) is a coleopteran herbivore that feeds on the foliage on Solanum species, in particular, potato. Six resistant wild Solanum species were identified, and two of these species had low levels of glycoalkaloids. Comparative analysis of the untargeted metabolite profiles of the foliage using UPLC-qTOF-MS was done to find metabolites shared between the wild species but not with Solanum tuberosum (L.) to identify resistance-related metabolites. It was found that only S. tuberosum produced the triose glycoalkaloids solanine and chaconine. Instead, the six wild species produced glycoalkaloids that shared in common tetrose sugar side chains. Additionally, there were non-glycoalkaloid metabolites associated with resistance including hydroxycoumarin and a phenylpropanoid, which were produced in all wild species but not in S. tuberosum.科罗拉多马铃薯甲虫（Leptinotarsa decemlineata (Say)，简称CPB）是一种鞘翅目植食性昆虫，主要取食茄属（Solanum）植物的叶片，尤以马铃薯为主要取食宿主。研究人员已鉴定出6种具有抗虫性的野生茄属植物，其中2种的糖苷生物碱（glycoalkaloids）含量较低。本研究通过超高效液相色谱-四极杆飞行时间质谱（UPLC-qTOF-MS）对供试叶片的非靶向代谢物谱（untargeted metabolite profiles）开展比较分析，以期筛选出野生茄属植物所共有、却未在普通栽培马铃薯（Solanum tuberosum (L.)）中出现的代谢物，进而鉴定与抗虫性相关的代谢物质。研究发现，仅普通栽培马铃薯可合成丙糖型糖苷生物碱茄碱（solanine）与查茄碱（chaconine）；而6种野生茄属植物所产生的糖苷生物碱均带有共通的丁糖糖侧链。此外，另有两类与抗虫性相关的非糖苷生物碱代谢物——羟基香豆素（hydroxycoumarin）与苯丙素类化合物（phenylpropanoid），仅在全部野生茄属植物中合成，未在普通栽培马铃薯中检出。