Fig. 5: Hypothesized flowering network in C.
pallens . In C. pallens , ATFL1 acts as the key floral
integrator gene. During non-inductive conditions, homologues of floral
repressors including FRI-like, AP2 and SVP can block the process of
floral transition. Photoperiodic (GI, CO) and vernalization (VRN1, VRN2)
pathways may interact to activate the expression of FT -like genes
during spring every year. However, only plants with sufficient internal
cues (e.g. sucrose content (TPS1 ), maturity (SPLs ) and
gibberellin (GA)) are able to respond to the external signals such as
summer temperatures (PIF4,5 ) which can then elevate the
expression of CpATFL1 to induce flowering in the following
season. The orange boxes indicate homologues of the floral integrator
genes identified in C. pallens. The solid lines indicate
co-expression of genes based on the transcriptomic data and known
literature, while the question mark indicates a hypothetical
co-regulation between two genes which may not have been discovered yet.
Genes represented with black and white ink, respectively represent the
up- and down-regulation in the expression of corresponding genes
observed in the tillers that flowered in the next season compared to
tillers that remained vegetative.