Differential proteomics study of postharvest Volvariella volvacea during storage at 4 °C

Abstract

The postharvest storage of Volvariella volvacea is an important factor limiting the industry development. Low-temperature storage is the traditional storage method used for most edible fungi, but V. volvacea undergoes autolysis at low temperature. To understand the molecular mechanism underlying the low-temperature autolysis of V. volvacea after harvesting, fruiting bodies of V. volvacea strain V23 were stored at 4 °C. Based on our previous study, in which the changes of morphological and physiological indexes during storage for 0, 6, 12, 24, 30, 36, 48 and 60 h were measured; four time points, namely, 0, 12, 24 and 60 h, were selected for this differential proteomics study. The proteomic changes in the postharvest storage samples were studied by isobaric tags for relative and absolute quantification-coupled two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS). A total of 2,063 proteins were identified, and 192 differentially expressed proteins (DEPs), including 24 up-regulated proteins and 168 down-regulated proteins, were detected after 12 h of storage. After 24 h of storage, 234 DEPs, including 48 up-regulated and 186 down-regulated proteins, were observed, and after 60 h, 415 DEPs, including 65 up-regulated proteins and 350 down-regulated proteins, were observed. An in-depth data analysis showed that the DEPs participated in various cellular processes, particularly metabolic processes. In this study, we combined Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, and the results focused on oxidative phosphorylation and ubiquitin mediated proteolysis pathways. In addition, sdh2, uba1 and ubc1 was confirmed by quantitative real-time polymerase chain reaction, and the results showed that the expression of these genes were consistent with their protein level. Based on the literature and our results, it is speculated that the identified DEPs, such as ATP1, SDH2, COR1, UBA1, COX4, UBC1 and SKP1 play a key role in the low-temperature autolysis of V. volvacea. Volvariella volvacea is a commercially important edible fungus cultivated in tropical and subtropical regions, particularly in Southeast Asian countries 1,2. In recent years, the market demand for V. volvacea has rapidly increased due to its unique flavor 3 and high nutritional value 4. V. volvacea also has pharmaceutical value because it contains antitumor polysaccharides and immunomodulatory lectins 5-7. V. volvacea is delicious and mainly sold fresh. In addition, this fungus exhibits rapid growth and development, has high respiratory intensity, and is easy-to-open umbrella at 28-35 °C, and these features are responsible for the loss of its edible value over a short period of time 8. In addition, V. volvacea is native to tropical and subtropical regions and is thus sensitive to low temperature. The fungus is usually autolysed at 0-5 °C 9,10 , and this autolysis accelerates its decay and causes softening and liquefaction. Therefore, the postharvest storage problem of V. volvacea has become a bottleneck that restr...

Comparative Proteomics Study on the Postharvest Senescence of Volvariella volvacea

“…Few studies have investigated SDH2 under stress, but its expression affects energy production. In this study, the SDH2 protein was up-regulated with 60 h and 96 h storage, which is consistent with the previous research results of low-temperature environmental storage [ 5 ]. The up-regulation of the SDH2 protein may provide more energy for V. volvacea cells to cope with the aging process.…”

“…The protein extraction methods were followed as described in a previous study [ 24 ]. Protein digestion and iTRAQ labeling were performed in accordance with the procedure described by Wisniewski et al and Zha et al [ 5 , 25 ]. The protein extraction, protein digestion, and iTRAQ labeling experimental steps are described in Zha et al [ 5 ].…”

“…All analyses were performed using a Q Exactive mass spectrometer equipped with a Nanospray Flex Ion Source (Thermo Fisher Scientific, Waltham, MA, USA). The methods are described in Zha et al [ 5 ].…”

“…V. volvacea , also called Chinese mushroom, is mainly cultivated in tropical and subtropical regions, and is a typical, high-temperature edible fungus suitable for growing in a high-temperature environment [ 4 ]. Delicious V. volvacea fruiting bodies are mainly sold fresh [ 5 ]. However, the fruiting bodies of V. volvacea actively undergo physiological metabolism and easily age under normal storage temperatures.…”

Long non-coding RNAs and their potential function in response to postharvest senescence of Sparassis latifolia during cold storage

“…Postharvest senescence of mushroom is a complex process accompanying with water loss, texture softening, nutrition loss, browning, flavor changes, and microbial attack, which seriously reduces its commercial worth 6 – 8 . In terms of studies on the postharvest changes of mushrooms, a few technologies have been applied to explore the related pathways, proteins and genes, including genome and transcriptome sequencing, proteomic and metabolomic analysis 9 , 10 . Postharvest age-related signaling pathways of Volvariella volvacea mainly including protein synthesis and transcription, fatty acid biosynthesis and metabolism, amino acid biosynthesis and metabolism and energy metabolism have been found using proteomics study 11 .…”