Isolation and Functional Analysis of EPHEMERAL1-LIKE ( EPH1L ) Genes Involved in Flower Senescence in Cultivated Japanese Gentians

• Published in: International journal of molecular sciences Vol. 23; no. 10; p. 5608
• Main Authors: Takahashi, Shigekazu, Yoshida, Chiharu, Takahashi, Hideyuki, Nishihara, Masahiro
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 17-05-2022; MDPI
• Subjects: Aging; corolla; CRISPR; CRISPR/Cas9; Cultivars; Elongation; EPHEMERAL1; flower longevity; Flowers; Flowers & plants; Flowers - metabolism; Functional analysis; Genes; genome editing; Genomes; Genomic analysis; Gentiana - genetics; Gentianaceae; Homology; Japanese gentian; Longevity; Ornamental plants; Phylogeny; Plant Senescence; Plants (botany); Senescence; Transcription Factors - metabolism; senescence; NAC transcription factor; genome editing; CRISPR/Cas9; corolla; flower longevity; EPHEMERAL1; Japanese gentian
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23105608

The elongation of flower longevity increases the commercial value of ornamental plants, and various genes have been identified as influencing flower senescence. Recently,
(
), encoding a NAC-type transcription factor, was identified in Japanese morning glory as a gene that promotes flower senescence. Here we attempted to identify an
homolog gene from cultivated Japanese gentians and characterized the same with regard to its flower senescence. Two
-
genes (
and
), considered as alleles, were isolated from a gentian cultivar (
×
). Phylogenetic analyses revealed that EPH1L belongs to the NAM subfamily. The transcript levels of
increased along with its senescence in the field-grown flowers. Under dark-induced senescence conditions, the gentian-detached flowers showed the peak transcription level of
earlier than that of
, a senescence marker gene, suggesting the involvement of
in flower senescence. To reveal the
function, we produced
-knockout mutant lines using the CRISPR/Cas9 system. When the flower longevity was evaluated using the detached flowers as described above, improved longevity was recorded in all genome-edited lines, with delayed induction of
transcription. The degradation analysis of genomic DNA matched the elongation of flower longevity, cumulatively indicating the involvement of
in the regulation of flower senescence in gentians.