The identification and functional verification of the cinnamate 4-hydroxylase gene from wax apple fruit and its role in lignin biosynthesis during nitric oxide-delayed postharvest cottony softening
Li-na Huang, Guang-bin Wu, Shen Zhang, Feng-Yuan Kuang and Fa-he Chen
Postharvest Biology and Technology, Volume 158, December 2019, 110964
2019
บทคัดย่อ
Cottony softening of harvested wax apple fruit is characterized by lignin accumulation, and it involves the activity of cinnamate-4-hydroxylase (C4H) and its encoding gene. This work investigated the characteristics and function of the C4H gene of wax apple fruit and discussed its relationship with lignin biosynthesis during nitric oxide (NO)-delayed cottony softening of harvested wax apple fruit. The C4H gene cloned from wax apple fruit was named SsC4H, and it has a length of 1849 bp and a 1518 bp open reading frame encoding 505 amino acids. The sequence of SsC4H-encoded amino acids contained typical C4H domains and shared high sequence similarity and close evolutionary relationships with C4H from other plants; in vitro catalytic activity of C4H was observed in the expressed and purified recombined SsC4H protein. Moreover, the SsC4H expression and C4H activities were inhibited in NO-treated wax apple fruit compared with control fruit, with lower lignin content and cottony softening index. Therefore, SsC4H was confirmed as the C4H gene for wax apple fruit, and the NO-retarded cottony softening of harvested wax apple fruit may be attributed to inhibited expression of SsC4H and C4H activity, delaying lignin biosynthesis.