Abstract
The evening complex of ELF4-ELF3-LUX proteins is an integral component of a plant circadian clock. LUX ARRHYTHMO (LUX) is one of the key components of the evening complex, and that play a key role in circadian rhythms and flowering. Here, we report that diverged soybean LUX has the additional role in male reproductive development. We studied diurnal and circadian rhythms of soybean LUX (GmLUXa, GmLUXb, and GmLUXc) using qRT-PCR, and show its nuclear localisation by particle bombardment. Yeast-two hybrid (Y2H) studies indicate that both GmLUXb and GmLUXc form an evening complex with GmELF4b and GmELF3a, respectively. Ectopic expression of GmLUXb in Arabidopsis lux mutants can complement functions of AtLUX, whereas GmLUXc generates novel phenotypes of serrated leaves, stunted plants, shortened anther filament, and low seed set. Overall, our results suggest that the LUX gene has diverged in soybean where GmLUXb and GmLUXc share the role to control flowering time, but GmLUXc has evolved to regulate anther filament growth and seed set by regulating the Gibberellin hormone biosynthesis pathway.
Highlights
The world’s population is projected to surpass 9 billion by 2050; feeding this enormous population requires a doubling of food production from the same amount of arable land
Three soybean homologues of LUX ARRHTHMO were identified in a soybean genome sequence database; they are designated as GmLUXa, GmLUXb, and GmLUXc
The fluorescence was located in the nucleus of bombarded epidermal cells, indicating GmLUXb::GFP and GmLUXc::GFP are localised in the nucleus (Fig. 1B)
Summary
The world’s population is projected to surpass 9 billion by 2050; feeding this enormous population requires a doubling of food production from the same amount of arable land. Our knowledge of molecular components of the circadian clock system controlling flowering of food legume crops is lacking[4]. The morning loop consists of two PSEUDO RESPONSE REGULATOR (PRR) 7 and 9, LATE ELONGATED HYPOCOTYL (LHY), CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1), and TIMING OF CAB EXPRESSION 1 (TOC1)) form the core loop[16], while the evening loop is a complex of ELF3, ELF4, and LUX17. Recent studies on Arabidopsis showed that plants have tissue-specific clocks, and evening complex components have tissue-specific expression patterns, but their functional significance is unknown. We characterise a soybean circadian clock gene in the evening complex, LUX ARRHYTHMO, GmLUXb, and GmLUXc and demonstrate conserved protein sequences, gene expression patterns, and subcellular localisation similar to Arabidopsis. This indicates that the GmLUXc drives anther filament elongation control and seed set by regulating the GA hormone biosynthesis pathway
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
