The LncRNA401-LrWRKY70 Module Regulates the Blue-Purple Flower Color Formation in Lycoris.

Area of Science:

• Plant Molecular Biology
• Plant Biochemistry
• Genetics and Genomics

Background:

• Lycoris plants exhibit diverse flower colors, but the underlying molecular mechanisms are not fully understood.
• Previous research has not elucidated the specific genetic and regulatory pathways controlling pigment synthesis in Lycoris.
• Understanding these pathways is crucial for comprehending plant secondary metabolism and for breeding efforts.

Purpose of the Study:

• To investigate the molecular basis of flower color variation in Lycoris, focusing on the blue-purple phenotype.
• To identify key genes, transcription factors, and regulatory elements involved in flavonoid and anthocyanin biosynthesis.
• To elucidate the regulatory network controlling pigment production in Lycoris petals.

Main Methods:

• Flower color was precisely measured using the CIELAB system.
• Metabolomic and transcriptomic analyses were performed on blue-purple (Lycoris sprengeri), white (Lycoris longituba), and red (Lycoris radiata var. pumila) petals.
• Identification and functional verification of a novel long non-coding RNA (LncRNA401) and its interaction with the LrWRKY70 transcription factor.

Main Results:

• Specific kaempferol glycosides accumulated in blue-purple petals.
• Differential expression of hydroxylase genes (LrF3'5'H, LrFLS, LrF3'H) determined distinct anthocyanin synthesis pathways (delphinidin vs. cyanidin).
• A novel regulatory module, LncRNA401-LrWRKY70, was identified, which activates downstream flavonoid biosynthesis genes, leading to the blue-purple phenotype.

Conclusions:

• The LncRNA401-LrWRKY70 module is a key regulator of metabolic reprogramming for flower color in Lycoris.
• This regulatory module significantly influences the synthesis of anthocyanins and kaempferol derivatives.
• The findings offer valuable insights into plant secondary metabolism and provide potential targets for breeding Lycoris with specific flower colors.