The role of 尾-hexosaminidase in peach (Prunus persica) fruit softening

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• 作者：Lijun Cao¹ ; Caiping Zhao¹ ; Suxiang Su ; Chuan Luo ; Mingyu Han ; ^{hanmy@nwsuaf.edu.cn" class="auth_mail}
• 关键词：Peach fruit ; Softening ; 尾-hexosaminidase ; Gene expression
• 刊名：Scientia Horticulturae
• 出版年：16 April, 2014
• 年：2014
• 卷：169
• 期：Complete
• 页码：226-233
• 全文大小：801 K

文摘

To determine the role of 尾-hex in peach fruit softening, we cloned two 尾-hexosaminidase (尾-hex) gene homologs, Pphex1 and Pphex2. Results showed that the full cDNA length of Pphex1 () was 1859 bp, containing an open reading frame (ORF) with 1689 bp and encoding a polypeptide of 562 amino acides. Pphex2 () was 2018 bp in length, containing an ORF with 1794 bp and encoding a polypeptide of 594 amino acides. Pphex1 and Pphex2 showed different expression patterns during peach fruit development and storage period. During peach fruit development, the Pphex1 expression initially decreased, but later increased towards ripening. However, Pphex2 expression was very low during fruit developmental stage, and then increased significantly towards ripening. During fruit storage, 尾-hexosaminidase activity increased in the first 6 days. The expression peak of Pphex1 occurred at the second day during storage. Pphex2 showed relative high expression during the whole storage period. Treatment with 2-Acetaindo-1,2-dideoxynojirimycin (2-ADN) caused inhibition in Pphex1 and Pphex2 transcription and 尾-hexosaminidase activity, at the same time, the rapid decline in fruit firmness was also delayed. Suppression of 2-ADN treated fruits in ethylene production, as well as the expression of PpACO and PpACS, and the activities of cell wall degrading enzymes (endo-PG, exo-PG, PME, and 尾-Gal) were also observed. Our study suggests the involvement of 尾-hex in the regulation of fruit softening in peach.