Impact of Tomato Grafts on the Potato Tuber Metabolome and Skin Colour

INTRODUCTION: Grafting is a traditional research and plant production technique used to study the long-distance movement of molecules and reduce disease susceptibility, respectively. Tomato/potato grafts are rare examples of successful interspecies grafting, even resulting in commercially available products. Nevertheless, information on the effect of tomato on the quality parameters of potato tubers is scarce.
MATERIALS AND METHODS: The tomato cultivar ‘Mobil’ was grafted with the potato cultivars ‘White Lady’, ‘Hópehely’ and ‘Désirée’, and the phenotype, metabolite composition, and starch and protein contents of tubers were analysed. Anthocyanins were isolated from the tuber skins, and the expression level of the transcription factor ANTHOCYANIN1 (StAN1) was evaluated.
RESULTS: Out of the 112 identified metabolites, the concentrations of twelve compounds were altered in the same direction in all three cultivars. The starch content of tubers was increased, while the protein level remained unaltered in ‘White Lady’ and ‘Hópehely’. The oval tubers became roundish. The tomato scion increased the anthocyanin content of ‘Hópehely’ and ‘Désirée’ tuber skins, which was correlated with the upregulation of StAN1 expression.
CONCLUSION: Tomato has a significant impact on the quality parameters of potato tubers and reduces the asparagine concentration and risk of acrylamide formation.

引言：嫁接是一项兼具科研与生产应用价值的传统技术，前者可用于研究分子的长距离运输过程，后者则可降低植株的病害易感性。番茄与马铃薯的种间嫁接是成功种间嫁接的罕见范例，其产物甚至已实现商业化应用。然而，目前关于番茄对马铃薯块茎品质参数影响的相关研究资料仍较为匮乏。
材料与方法：以番茄品种‘Mobil’为接穗，分别与马铃薯品种‘White Lady’、‘Hópehely’及‘Désirée’进行嫁接组合，随后对块茎的表型特征、代谢物组成、淀粉与蛋白质含量展开分析。从块茎表皮中分离得到花青素，并对转录因子ANTHOCYANIN1（StAN1）的表达水平进行检测。
结果：本次研究共鉴定出112种代谢物，其中12种化合物的浓度在三个马铃薯品种中均发生了同向变化。‘White Lady’与‘Hópehely’的块茎淀粉含量显著升高，而其蛋白质水平未发生明显改变。原本呈椭圆形的块茎形态变为近圆形。番茄接穗可提升‘Hópehely’与‘Désirée’块茎表皮的花青素含量，该变化与StAN1的表达上调呈显著相关。
结论：番茄接穗对马铃薯块茎的品质参数具有显著影响，可降低块茎中天冬酰胺的浓度以及丙烯酰胺生成风险。