Aung Htay Naing, Kyeung Il Park, Trinh Ngoc Ai, Mi Young Chung, Jeung Sul Han, Young-Wha Kang, Ki Byung Lim and Chang Kil Kim

BMC Plant Biology; 23 March 2017, DOI: 10.1186/s12870-017-1015-5

Abstract

Background

Rosea1 (Ros1) and Delila (Del) co-expression controls anthocyanin accumulation in snapdragon flowers, while their overexpression in tomato strongly induces anthocyanin accumulation. However, little data exist on how Del expression alone influences anthocyanin accumulation.

Results

In tobacco (Nicotiana tabacum ‘Xanthi’), Del expression enhanced leaf and flower anthocyanin production through regulating NtCHS, NtCHI, NtF3H, NtDFR, and NtANS transcript levels. Transgenic lines displayed different anthocyanin colors (e.g., pale red: T₀-P, red: T₀-R, and strong red: T₀-S), resulting from varying levels of biosynthetic gene transcripts. Under salt stress, the T₂ generation had higher total polyphenol content, radical (DPPH, ABTS) scavenging activities, antioxidant-related gene expression, as well as overall greater salt and drought tolerance than wild type (WT).

Conclusion

We propose that Del overexpression elevates transcript levels of anthocyanin biosynthetic and antioxidant-related genes, leading to enhanced anthocyanin production and antioxidant activity. The resultant increase of anthocyanin and antioxidant activity improves abiotic stress tolerance.

See: http://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-017-1015-5

Fig. 1

Comparing anthocyanin-content phenotypes across (a) three independent Del-overexpressing transgenic lines (in vitro stage) and across (b) WT and transgenic lines (in greenhouse conditions). All lines exhibited different phenotypes. T₀-P, T₀-R, and T₀-S refer to pale red, red, and strong red transgenic plants in the T₀ generation, respectively