Escobar Rodríguez Carolina, Novak Johannes, Buchholz Franziska, Uetz Pia, Bragagna Laura, Gumze Marija, Antonielli Livio, Mitter Birgit
FFoQSI GmbH - Austrian Competence Centre for Feed and Food Quality, Safety and Innovation, Tulln, Austria.
Institute of Applied Botany and Pharmacognosy (IAB), Veterinary University of Vienna, Vienna, Austria.
Front Plant Sci. 2021 Dec 24;12:775722. doi: 10.3389/fpls.2021.775722. eCollection 2021.
The modes of interactions between plants and plant-associated microbiota are manifold, and secondary metabolites often play a central role in plant-microbe interactions. Abiotic and biotic (including both plant pathogens and endophytes) stress can affect the composition and concentration of secondary plant metabolites, and thus have an influence on chemical compounds that make up for the taste and aroma of fruit. While the role of microbiota in growth and health of plants is widely acknowledged, relatively little is known about the possible effect of microorganisms on the quality of fruit of plants they are colonizing. In this work, tomato ( L.) plants of five different cultivars were grown in soil and in hydroponics to investigate the impact of the cultivation method on the flavor of fruit, and to assess whether variations in their chemical composition are attributable to shifts in bacterial microbiota. Ripe fruit were harvested and used for bacterial community analysis and for the analysis of tomato volatiles, sugars and acids, all contributing to flavor. Fruit grown in soil showed significantly higher sugar content, whereas tomatoes from plants under hydroponic conditions had significantly higher levels of organic acids. In contrast, aroma profiles of fruit were shaped by the tomato cultivars, rather than the cultivation method. In terms of bacterial communities, the cultivation method significantly defined the community composition in all cultivars, with the bacterial communities in hydroponic tomatoes being more variable that those in tomatoes grown in soil. Bacterial indicator species in soil-grown tomatoes correlated with higher concentrations of volatiles described to be perceived as "green" or "pungent." A soil-grown specific reproducibly occurring ASV (amplicon sequence variants) classified as detected solely in "Solarino" tomatoes, which were the sweetest among all cultivars, correlated with the amount of aroma-relevant volatiles as well as of fructose and glucose in the fruit. In contrast, indicator bacterial species in hydroponic-derived tomatoes correlated with aroma compounds with "sweet" and "floral" notes and showed negative correlations with glucose concentrations in fruit. Overall, our results point toward a microbiota-related accumulation of flavor and aroma compounds in tomato fruit, which is strongly dependent on the cultivation substrate and approach.
植物与植物相关微生物群之间的相互作用方式多种多样，次生代谢产物通常在植物与微生物的相互作用中发挥核心作用。非生物和生物（包括植物病原体和内生菌）胁迫会影响植物次生代谢产物的组成和浓度，进而影响构成果实味道和香气的化合物。虽然微生物群在植物生长和健康中的作用已得到广泛认可，但对于微生物对其定殖植物果实品质可能产生的影响却知之甚少。在这项研究中，种植了五个不同品种的番茄（L.）植株，分别采用土壤栽培和水培方式，以研究栽培方法对果实风味的影响，并评估其化学成分的变化是否归因于细菌微生物群的变化。收获成熟果实，用于细菌群落分析以及番茄挥发物、糖分和酸的分析，这些都对风味有影响。土壤栽培的果实糖分含量显著更高，而水培条件下植株所结番茄的有机酸含量显著更高。相比之下，果实的香气特征由番茄品种决定，而非栽培方法。在细菌群落方面，栽培方法显著决定了所有品种的群落组成，水培番茄中的细菌群落比土壤栽培番茄中的更具变异性。土壤栽培番茄中的细菌指示物种与被描述为“绿色”或“刺鼻”的较高浓度挥发物相关。一种仅在“索拉利诺”番茄中检测到的土壤栽培特异性可重复出现的扩增子序列变体（ASV），“索拉利诺”是所有品种中最甜的，它与果实中与香气相关的挥发物以及果糖和葡萄糖的含量相关。相比之下，水培番茄中的指示细菌物种与带有“甜味”和“花香”的香气化合物相关，并且与果实中的葡萄糖浓度呈负相关。总体而言，我们的结果表明番茄果实中风味和香气化合物的积累与微生物群有关，这在很大程度上取决于栽培基质和方法。
