Individual Shrink Wrapping of Zucchini Fruit Improves Postharvest Chilling Tolerance Associated with a Reduction in Ethylene Production and Oxidative Stress Metabolites

PLoS One. 2015 Jul 15;10(7):e0133058. doi: 10.1371/journal.pone.0133058. eCollection 2015.

Abstract

We have studied the effect of individual shrink wrapping (ISW) on the postharvest performance of refrigerated fruit from two zucchini cultivars that differ in their sensitivity to cold storage: Sinatra (more sensitive) and Natura (more tolerant). The fruit was individually shrink wrapped before storing at 4°C for 0, 7 and 14 days. Quality parameters, ethylene and CO2 productions, ethylene gene expression, and oxidative stress metabolites were assessed in shrink wrapped and non-wrapped fruit after conditioning the fruit for 6 hours at 20°C. ISW decreased significantly the postharvest deterioration of chilled zucchini in both cultivars. Weight loss was reduced to less than 1%, pitting symptoms were completely absent in ISW fruit at 7 days, and were less than 25% those of control fruits at 14 days of cold storage, and firmness loss was significantly reduced in the cultivar Sinatra. These enhancements in quality of ISW fruit were associated with a significant reduction in cold-induced ethylene production, in the respiration rate, and in the level of oxidative stress metabolites such as hydrogen peroxide and malonyldialdehyde (MDA). A detailed expression analysis of ethylene biosynthesis, perception and signaling genes demonstrated a downregulation of CpACS1 and CpACO1 genes in response to ISW, two genes that are upregulated by cold storage. However, the expression patterns of six other ethylene biosynthesis genes (CpACS2 to CpACS7) and five ethylene signal transduction pathway genes (CpCTR1, CpETR1, CpERS1, CpEIN3.1 and CpEN3.2), suggest that they do not play a major role in response to cold storage and ISW packaging. In conclusion, ISW zucchini packaging resulted in improved tolerance to chilling concomitantly with a reduction in oxidative stress, respiration rate and ethylene production, as well as in the expression of ethylene biosynthesis genes, but not of those involved in ethylene perception and sensitivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / genetics*
  • Carbon Dioxide / metabolism
  • Cold Temperature
  • Cucurbitaceae / genetics*
  • Cucurbitaceae / metabolism
  • Ethylenes / biosynthesis
  • Food Packaging / methods*
  • Fruit / genetics*
  • Fruit / metabolism
  • Gene Expression Regulation, Plant*
  • Hydrogen Peroxide / metabolism
  • Iron Regulatory Protein 1 / genetics
  • Iron Regulatory Protein 1 / metabolism
  • Lyases / genetics
  • Lyases / metabolism
  • Malondialdehyde / metabolism
  • Oxidative Stress
  • Plant Growth Regulators / biosynthesis
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Refrigeration
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Ethylenes
  • Plant Growth Regulators
  • Plant Proteins
  • Transcription Factors
  • Carbon Dioxide
  • Malondialdehyde
  • ethylene
  • Hydrogen Peroxide
  • Lyases
  • Iron Regulatory Protein 1

Grants and funding

This work was supported by grants AGL2011-30568-C02/ALI from the Spanish Ministry of Science and Innovation, and AGR1423 from the Consejería de Economía, Innovación y Ciencia, Junta de Andalucía, Spain. Z.M. acknowledges FPU program scholarships from MEC, Spain. S.M. is funded by grant PTA2011-479-I from the Spanish Ministry of Science and Innovation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.