Gene Expression Analysis of Deduced Protein Sequence from the FLOWERING LOCUS C (FLC) Homolog during Vegetative and Reproductive Phases in Lepidium sativum L.

The transition of the shoot apical meristem from vegetative to reproductive phases is a critical stage in the plant life cycle. In contrast, the success of reproduction depends on the flowering initiation timing. One of the key repressors of flowering is the gene FLOWERING LOCUS C (FLC), which is important for determining flowering time. The present study, therefore, aimed to identify and investigate the expression patterns of Lepidium sativum genes, considering FLC. Specific primers were designed for the RT-PCR assays, amplifying a 361-nucleotide fragment of the LsFLC gene, recorded in the NCBI database under the accession number GenBank: KT582105.1. The sequenced fragment encoded for a deduced protein sequence of 120 amino acids. The expression of LsFLC in different plant organs was analyzed at various phenological stages, namely two days (early stage of vegetative development), 13 days (early vegetative stage), 28 days (vegetative maturity or transition stage), and during reproductive development stages, which fall on 33 days (early reproductive stage) and 34 days (flowering stage). Results showed that LsFLC expression levels were very high in the root and relatively high in leaves and stems, whereas no expression was allowed in flowers. Indeed, the mRNA levels were much higher during the vegetative phase compared to the transition to flowering, therefore agreeing with the known role of FLC as a promoter of vegetative growth and an inhibitor of flowering. Phylogenetic analysis showed that the LsFLC gene has a close relationship with Brassicaceae members, in particular with the highest homology with Arabidopsis lyrata. The current study has contributed to the knowledge of the functions of LsFLC proteins during the phenology of L. sativum and could contribute to strategies developed for improving this species in desirable traits.