Ethylene is required for both the initiation and progression of softening in pear (Pyrus communis L.) fruit

Kyoko Hiwasa, Yuichi Kinugasa, Satomi Amano, Akiko Hashimoto, Ryohei Nakano, Akitsugu Inaba, Yasutaka Kubo

Research output: Contribution to journalArticlepeer-review

203 Citations (Scopus)


In order to investigate the physiological role of ethylene in the initiation and subsequent progression of softening, pear fruit were treated with propylene, an analogue of ethylene or 1-methylcyclopropene (1-MCP), a gaseous inhibitor of ethylene action at the preclimacteric or ripening stages. The propylene treatment at the pre-ripe stage stimulated ethylene production and flesh softening while the 1-MCP treatment at the same stage markedly retarded the initiation of the ripening-related events. Moreover, 1-MCP treatment after the initiation of ripening markedly suppressed the subsequent flesh softening and ethylene production. These results clearly indicate that ethylene is not merely a by-product, but plays a crucial role in both the initiation and maintenance of regulating the softening process during ripening. The observations also suggest that ethylene in ripening is regulated entirely in an autocatalytic manner. The mRNA accumulation of pear polygalacturonases (PG) genes, PC-PG1 and PC-PG2, was in parallel with the pattern of fruit softening in both propylene and 1-MCP treatments. However, the expression pattern of pear endo-1,4-β-D-glucanases (EGase) genes, PC-EG1 and PC-EG2, was not affected in both treatments. The results suggest that ethylene is required for PGs expression even in the late ripening stage, but not for EGases.

Original languageEnglish
Pages (from-to)771-779
Number of pages9
JournalJournal of experimental botany
Issue number383
Publication statusPublished - Feb 2003


  • 1-methyl-cyclopropene
  • Endo-1,4-β--glucanase
  • Ethylene
  • Pear fruit ripening
  • Polygalacturonase
  • Softening

ASJC Scopus subject areas

  • Physiology
  • Plant Science


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