Function analysis of GmELF3s in regulating soybean flowering time and circadian rhythm

Abstract

<p id="C3">Soybean is a typical short-day crop. Photoperiod sensitivity seriously affects flowering time, yield, and planting range of soybean, but the mechanism underlying photoperiod and circadian rhythm regulation is still unclear. In <italic>Arabidopsis thaliana</italic>, ELF3, together with ELF4 and LUX, forms the ELF4-ELF3-LUX complex (Evening Complex, EC), which plays an important role in circadian rhythm and flowering time regulation. In this study, soybean mutants of <italic>Gmelf3a/j</italic>, <italic>Gmelf3b-1</italic>, and <italic>Gmelf3b-2 </italic>were obtained by CRISPR/Cas9 gene editing system. We found that GmELF3b-1 regulated the flowering time in soybean under long-day conditions by observing flowering phenotypes in these mutants. The phenotypes of heterozygous double mutants revealed that there was functional redundancy among GmELF3a/J, GmELF3b-1<italic>, </italic>and GmELF3b-2 in regulating flowering time of soybean. Through detecting the expression of circadian related genes in soybean by using qRT-PCR, it was found that the relative expression patterns of <italic>GmCAB</italic>, <italic>GmPRR9a</italic>, and <italic>GmPRR7a</italic> were changed in soybean. In summary, these results suggested that GmELF3a/J, GmELF3b-1, and GmELF3b-2 may regulate the circadian rhythm and flowering time through GmPRR9a and GmPRR7a in soybean.