Tobaruela Eric de Castro, Gomes Bruna Lima, Bonato Vanessa Caroline de Barros, de Lima Elis Silva, Freschi Luciano, Purgatto Eduardo
Department of Food and Experimental Nutrition, School of Pharmaceutical Sciences, University of São Paulo (USP), São Paulo, Brazil.
Food Research Center (FoRC), São Paulo, Brazil.
Front Plant Sci. 2021 Dec 10;12:765897. doi: 10.3389/fpls.2021.765897. eCollection 2021.
As the auxin-ethylene interaction in climacteric fruit ripening has been highlighted, the hormonal regulation of aroma changes in climacteric fruits requires clarification. The influence of both phytohormones on the volatile organic compound (VOC) metabolism was evaluated during tomato ( L.) fruit ripening. Tomato fruits cv. Micro-Tom and Sweet Grape at the mature green stage were randomly grouped according to treatment with ethylene (ETHY), auxin (IAA), or both (ETHY + IAA). At middle ripening, Micro-Tom ETHY + IAA fruits present VOC profiles similar to those of ETHY fruits, while Sweet Grape presents VOC profiles closer to those of IAA fruits. At full ripeness, Micro-Tom and Sweet Grape ETHY + IAA fruits show profiles closer to those of IAA fruits, suggesting that the auxin overlaps the ethylene effects. Aroma compounds positively correlated with consumer preferences (2-isobutylthiazole, 6-methyl-5-hepten-2-one, and others) are identified in both cultivars and have their contents affected by both hormone treatments. The transcription of genes related to the biosynthesis of important tomato VOCs that have fatty-acid and carotenoid precursors evidences their regulation by both plant hormones. Additionally, the results indicate that the observed effects on the VOC metabolism are not restricted to the Micro-Tom cultivar, as these are also observed in the Sweet Grape cultivar. In conclusion, ethylene and auxin directly regulate the metabolic pathways related to VOC formation, impacting tomato aroma formation during ripening since Micro-Tom fruits apparently at the same maturation stage have different aromas.
由于跃变型果实成熟过程中生长素与乙烯的相互作用备受关注，因此需要阐明跃变型果实香气变化的激素调控机制。在番茄（L.）果实成熟过程中，评估了这两种植物激素对挥发性有机化合物（VOC）代谢的影响。将处于绿熟期的Micro-Tom和Sweet Grape番茄品种的果实，根据乙烯（ETHY）、生长素（IAA）或两者（ETHY + IAA）处理进行随机分组。在果实成熟中期，Micro-Tom ETHY + IAA处理的果实呈现出与ETHY处理果实相似的VOC图谱，而Sweet Grape处理的果实呈现出更接近IAA处理果实的VOC图谱。在果实完熟时，Micro-Tom和Sweet Grape ETHY + IAA处理的果实表现出更接近IAA处理果实的图谱，这表明生长素重叠了乙烯的作用。在两个品种中均鉴定出与消费者偏好呈正相关的香气化合物（2-异丁基噻唑、6-甲基-5-庚烯-2-酮等），且其含量受两种激素处理的影响。与具有脂肪酸和类胡萝卜素前体的重要番茄VOC生物合成相关基因的转录，证明了它们受这两种植物激素的调控。此外，结果表明，观察到的对VOC代谢的影响并不局限于Micro-Tom品种，因为在Sweet Grape品种中也观察到了这些影响。总之，乙烯和生长素直接调节与VOC形成相关的代谢途径，影响番茄成熟过程中的香气形成，因为处于相同成熟阶段的Micro-Tom果实显然具有不同的香气。
