Expression patterns of volatile vompounds during ‘FL 47’ tomato ripening and their response to exogenous methyl salicylate (MeSA) fumigation

Authors: JIA, LUTING - Nanjing Agricultural University; WANG, LI - Nanjing Agricultural University; XIA, QIANG - Nanjing Agricultural University; LUO, WEIQI - North Carolina State University; QIAO, XIN - Nanjing Agricultural University; ZHANG, XU - Nanjing Agricultural University; LI, JIAN - China Agricultural University; BALDWIN, ELIZABETH - Retired ARS Employee; JIANG, LI - Nanjing Agricultural University; ZHAO, YADONG - Nanjing Agricultural University; CAO, ZHAOXIN - Nanjing Forestry University; WANG, LIBIN - Nanjing Forestry University; Bai, Jinhe

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2023
Publication Date: 5/30/2023
Citation: Jia, L., Wang, L., Xia, Q., Luo, W., Qiao, X., Zhang, X., Li, J., Baldwin, E., Jiang, L., Zhao, Y., Cao, Z., Wang, L., Bai, J. 2023. Expression patterns of volatile vompounds during ‘FL 47’ tomato ripening and their response to exogenous methyl salicylate (MeSA) fumigation. Postharvest Biology and Technology. https://doi.org/10.1016/j.postharvbio.2023.112414.
DOI: https://doi.org/10.1016/j.postharvbio.2023.112414

Interpretive Summary: Consumers have been disappointed with flavorless tomatoes. Various efforts have been made to regulate fruit mature process and improve fruit flavor quality. In this report, we fumigated mature green tomatoes with methyl salicylate, and evaluated how the treatment affects fruit ripening and volatile production. The study validated the role of ethylene in apocarotenoid volatile biosynthesis. The formation of 24 volatiles in red fruit were greatly suppressed in MeSA-treated fruit along with lower ethylene; and the reduction of apocarotenoid volatiles was associated with the downregulated SlPSY1 & SlCCD1A/B transcripts and carotenoid levels when compared with control. In spite of the alternation in the formation of over 60% of tomato volatiles after MeSA fumigation, no difference in total volatile abundance and aroma quality were observed between samples; however, the taste quality may have been altered by MeSA treatment due to lowered TSS and TSS/TA.

Technical Abstract: Aroma, a complex mixture of volatiles, is essential for tomato flavor; however, the expression patterns of most volatile compounds and their response to exogenous methyl salicylate (MeSA) treatment are still unclarified. In this study, in association with the alteration in ethylene evolution and its biosynthetic genes (SlACO1 and SlACS2/4), 31 volatiles fluctuated or accumulated during ‘FL 47’ tomato ripening with a burst at pink or red stage, resulting in the alteration in aroma quality. Meanwhile, the alternation of 29 volatiles, lycopene and ß-carotenoid content as well as SlPSY1 and SlCCD1A/B mRNAs demonstrated a strong correlation with ethylene evolution. Further study validated the role of ethylene in apocarotenoid volatile biosynthesis. The formation of 24 volatiles were greatly suppressed in MeSA-treated fruit at red stage along with lower ethylene. In addition, the reduction of apocarotenoid volatiles was associated with downregulated SlPSY1 and SlCCD1A/B mRNAs and carotenoid accumulation when compared with control. These results imply that ethylene plays a critical role in MeSA-induced reduction of apocarotenoid volatiles via its influence on carotenoid biosynthesis and SlCCD1A/B expression. Although the formation of over 60% of the tomato volatiles was altered by MeSA fumigation, no difference in total volatile abundance or aroma quality could be detected between samples. On the other hand, the taste quality was substantiality altered by MeSA treatment in association with the reduction of TSS and TA. Taken together, our results illustrated that MeSA application for fruit quality control was at the expense of flavor alternation.