Physiology and Genetics of Continuous Flowering in Plants.

Continuous flowering, a key adaptive trait in perennial plants, confers significant ornamental and breeding value. Here, we review the developmental patterns, transcriptional and epigenetic regulation underlying continuous flowering. Key genetic loci, including SFL, PFRU, and RB, are discussed. At the transcriptional level, continuous flowering is closely associated with loss-of-function mutations in KSN (including frameshifts, transposon insertions, large deletions, and SNP). In roses, epigenetic modifications such as promoter hypermethylation fine-tune KSN expression via a transcriptional dosage mechanism. Given that continuous flowering plants often exhibit distinct life cycles and branching architectures from once-flowering plants, we hypothesise the existence of a regulatory pathway linking branching development to continuous flowering. Future studies should explore epigenetic and post-translational regulation, flowering capacity-quality trade-offs, and cross-species comparisons to advance molecular breeding.