Three pea (Pisum sativum) loci controlling photoperiod sensitivity, HIGH RESPONSE (HR), DIE NEUTRALIS (DNE), and STERILE NODES (SN), have recently been shown to correspond to orthologs of Arabidopsis (Arabidopsis thaliana) circadian clock genes EARLY FLOWERING3 (ELF3), ELF4, and LUX ARRHYTHMO, respectively. A fourth pea locus, PHOTOPERIOD (PPD), also contributes to the photoperiod response in a similar manner to SN and DNE, and recessive ppd mutants on a spring-flowering hr mutant background show early, photoperiod-insensitive flowering. However, the molecular identity of PPD has so far remained elusive. Here, we show that the PPD locus also has a role in maintenance of diurnal and circadian gene expression rhythms and identify PPD as an ELF3 co-ortholog, termed ELF3b. Genetic interactions between pea ELF3 genes suggest that loss of PPD function does not affect flowering time in the presence of functional HR, whereas PPD can compensate only partially for the lack of HR. These results provide an illustration of how gene duplication and divergence can generate potential for the emergence of more subtle variations in phenotype that may be adaptively significant.

Item Type:	Refereed Article
Keywords:	pea, legume, flowering, photoperiod, circadian clock
Research Division:	Biological Sciences
Research Group:	Plant biology
Research Field:	Plant physiology
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Grains and seeds
Objective Field:	Grain legumes
UTAS Author:	Rubenach, AJS (Mr Andrew Rubenach)
UTAS Author:	Hecht, V (Dr Valerie Hecht)
UTAS Author:	Vander Schoor, JK (Mrs Jacqueline Vander Schoor)
UTAS Author:	Liew, LC (Miss Lim Chee Liew)
UTAS Author:	Weller, JL (Associate Professor Jim Weller)
ID Code:	117650
Year Published:	2017
Funding Support:	Australian Research Council (DP160100793)
Web of Science® Times Cited:	9
Deposited By:	Plant Science
Deposited On:	2017-06-22
Last Modified:	2018-04-30
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