Fig. 5: Hypothesised 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 vernalisation (VRN1, VRN2)
pathways may interact to activate the expression of FT -like genes
during inductive conditions 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 yellow 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 question mark indicates a hypothetical co-regulation
between two genes which may exist in model species but have not been
discovered yet. Genes represented with the black and the 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.