Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali (DAGRI), University of Florence, Viale delle idee 30, 50019, Florence, Italy.
A.R.E.A. Foundation, via Tavoleria 28, 56125, Pisa, Italy.
BMC Genomics. 2020 Jan 29;21(1):90. doi: 10.1186/s12864-020-6522-3.
Truffles are symbiotic fungi that develop underground in association with plant roots, forming ectomycorrhizae. They are primarily known for the organoleptic qualities of their hypogeous fruiting bodies. Primarily, Tuber magnatum Pico is a greatly appreciated truffle species mainly distributed in Italy and Balkans. Its price and features are mostly depending on its geographical origin. However, the genetic variation within T. magnatum has been only partially investigated as well as its adaptation to several environments.
Here, we applied an integrated omic strategy to T. magnatum fruiting bodies collected during several seasons from three different areas located in the North, Center and South of Italy, with the aim to distinguish them according to molecular and biochemical traits and to verify the impact of several environments on these properties. With the proteomic approach based on two-dimensional electrophoresis (2-DE) followed by mass spectrometry, we were able to identify proteins specifically linked to the sample origin. We further associated the proteomic results to an RNA-seq profiling, which confirmed the possibility to differentiate samples according to their source and provided a basis for the detailed analysis of genes involved in sulfur metabolism. Finally, geographical specificities were associated with the set of volatile compounds produced by the fruiting bodies, as quantitatively and qualitatively determined through proton transfer reaction-mass spectrometry (PTR-MS) and gas-chromatography-mass spectrometry (GC-MS). In particular, a partial least squares-discriminant analysis (PLS-DA) model built from the latter data was able to return high confidence predictions of sample source.
Results provide a characterization of white fruiting bodies by a wide range of different molecules, suggesting the role for specific compounds in the responses and adaptation to distinct environments.
块菌是与植物根系共生形成外生菌根的地下共生真菌。它们主要以其地下子实体的感官品质而闻名。主要的白块菌（Tuber magnatum Pico）是一种非常受欢迎的块菌物种，主要分布在意大利和巴尔干地区。它的价格和特点主要取决于其地理起源。然而，对 T. magnatum 的遗传变异的研究还很不完善，对其适应多种环境的研究也很少。
在这里，我们应用了一种综合的组学策略，对从意大利北部、中部和南部三个不同地区在多个季节收集的 T. magnatum 子实体进行研究，目的是根据分子和生化特征将它们区分开来，并验证几个环境对这些特性的影响。通过基于二维电泳（2-DE）的蛋白质组学方法和质谱分析，我们能够鉴定出与样品来源特异性相关的蛋白质。我们进一步将蛋白质组学结果与 RNA-seq 分析相结合，证实了根据来源对样品进行区分的可能性，并为参与硫代谢的基因的详细分析提供了基础。最后，通过质子转移反应-质谱（PTR-MS）和气相色谱-质谱（GC-MS）定量和定性地确定，将地理特异性与子实体产生的挥发性化合物集相关联。特别是，从后者的数据构建的偏最小二乘判别分析（PLS-DA）模型能够高度置信地预测样品来源。
研究结果提供了对白子实体的多种不同分子的特征描述，表明特定化合物在对不同环境的响应和适应中起作用。
