The mechanism analysis of exogenous melatonin in limiting pear fruit aroma decrease under low temperature storage

PeerJ. 2022 Oct 14:10:e14166. doi: 10.7717/peerj.14166. eCollection 2022.

Abstract

Exogenous melatonin (MT) is widely used in fruit preservation, and can increase the storage time and delay the quality deterioration. Firstly, it was found that 150 μM MT was the optimal concentration to treat 'Xinli No.7' under storage at 4 °C for 60 days. MT could significantly improve oxidase activity and inhibit the reduction of physiological indexes, including pulp hardness, weight loss, titratable acid and soluble solid content. MT could also reduce ethylene release and limit the reduction of fruit aroma. The average content of fruit aroma substance increased by 43.53%. A relevant RNA-Seq database was built to further explore the regulation mechanism of MT. A total of 2,761 differentially expressed genes (DEGs) were identified. DEGs were enriched in 64 functional groups and 191 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. DEGs were mainly enriched in alpha-linolenic acid metabolism, fatty acid metabolism and plant hormone signal transduction pathway. The gene pycom09g05270 belonging to long chain acyl-CoA synthetase family and participating in fatty acid metabolism pathway was identified, and its expression level was consistent with fragments per kilobase per million mapped reads (FPKM) values, implying that pycom09g05270 might play a vital role in maintaining quality during the storage process.

Keywords: Aroma; Melatonin; Pear.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fatty Acids / metabolism
  • Fruit / genetics
  • Melatonin* / metabolism
  • Odorants / analysis
  • Pyrus* / genetics
  • Temperature

Substances

  • Melatonin
  • Fatty Acids

Grants and funding

The research was supported by the grant from the China Agriculture Research System of MOF and MARA (CARS-28-36), the Shandong Province Agricultural Improved Seed Project (2019LZGC008), the National Natural Science Foundation of China (31801845), and the Natural Science Foundation of Shandong Province (ZR2019BC075, ZR2020MC141, ZR2021MC177). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.