Association Between Dormancy Release and Phenolic Metabolic Alteration Induced by Low Temperature in Cardiocrinum giganteum Bulbs

Abstract:

Cardiocrinum giganteum, a perennial bulbous plant of family Liliaceaeas, is an important medicinal and food homologous plant. The bulbs have typical dormancy characteristics, and low temperature is a major environmental factor to relieve dormancy of lily bulbs. In order to reveal the molecular mechanism of dormancy dissolution of Lily bulbs, metabolome and transcriptome analysis were performed on bulbs treated at 4 ℃ for 0, 30 and 60 days, respectively. The results showed that dormancy release of bud was related to the metabolism of phenols, and the degradation of phenols was beneficial to the release of dormancy, among which PALs gene might play a major role in this process. Meanwhile, members of transcription factor families such as bHLH, bZIP, MYB and MADS were all significantly related with phenolic metabolites and involved in bulb dormancy release. Co-expression analysis further confirmed that PAL, CAD and POD were important regulatory genes for phenolic metabolism, MYB4, MYB114 and ICE1 were involved in the regulatory network of phenolic metabolism, and ICE1 might be the key factor connecting temperature signals and phenolic metabolism. Therefore, the interaction of these transcription factors with phenols might play an important role in breaking dormancy of bulbs.

Key words:Low temperature;Phenols;Dormancy release;Metabolome;Transcriptome;Co-expression