GmIAA27 Encodes an AUX/IAA Protein Involved in Dwarfing and Multi-Branching in Soybean

Abstract

Soybean plant height and branching affect plant architecture and yield potential in soybean. In this study, the mutant dmbn was obtained by treating the cultivar Zhongpin 661 with ethylmethane sulfonate. The dmbn mutant plants were shorter and more branched than the wild type. The genetic analysis showed that the mutant trait was controlled by a semi-dominant gene. The candidate gene was fine-mapped to a 91 kb interval on Chromosome 9 by combining BSA-seq and linkage analysis. Sequence analysis revealed that Glyma.09g193000 encoding an Aux/IAA protein (GmIAA27) was mutated from C to T in the second exon of the coding region, resulting to amino acid substitution of proline to leucine. Overexpression of the mutant type of this gene in Arabidopsis thaliana inhibited apical dominance and promoted lateral branch development. Expression analysis of GmIAA27 and auxin response genes revealed that some GH3 genes were induced. GmIAA27 relies on auxin to interact with TIR1, whereas Gmiaa27 cannot interact with TIR1 owing to the mutation in the degron motif. Identification of this unique gene that controls soybean plant height and branch development provides a basis for investigating the mechanisms regulating soybean plant architecture development.

Genetic dissection of the soybean dwarf mutant dm with integrated genomic, transcriptomic and methylomic analyses

“…Genes in plant hormone signal pathways regulate the soybean height or dwarfism. These hormones including BR, SLs, GA and IAA, may also be involved in regulating plant height ( Itoh et al., 2004 ; Lin et al., 2009 ; Hirano et al., 2010 ; Tong et al., 2010 ; Sun, 2011 ; Yang et al., 2011 ; Li et al., 2014 ; Zhou et al., 2015 ; Li et al., 2018b ; Roy et al., 2021 ; Su et al., 2022 ; Zegeye et al., 2022 ). Our results also identified DEGs in hormone and signal transduction pathways, including Glyma.06G063500 (KEGG ID: ARR-B, panther ID: TWO-COMPONENT RESPONSE REGULATOR ARR18), Glyma.03G148300 (KEGG ID: GID1, panther ID: GIBBERELLIN RECEPTOR GID1B), Glyma.14G041500 (KEGG ID: EIN3, panther ID: ETHYLENE INSENSITIVE 3-LIKE 1 PROTEIN-RELATED).…”

“…Dwarfism, a reduced plant height, is a desirable characteristic in crop breeding for improved response to fertilizer input, lodging resistance, enhanced light utilization, etc. ( Cooper et al., 1995 ; Cooper et al., 2003 ; Hedden, 2003 ; Wei et al., 2021 ; Su et al., 2022 ). Semi-dwarf varieties have been introduced in many crop species, e.g., wheat, rice, and soybean, such as Hobbit87, Charleston, and Apex ( Peng et al., 1999 ; Cooper et al., 1995 ; Khush, 2001 ; Cooper et al., 2003 ; Hedden, 2003 ).…”

“…Studies show that the genetic control of plant height can be regulated by a single dwarf gene or multiple associated genetic loci or genes ( Kuraparthy et al., 2008 ; Dardick et al., 2013 ; Roy et al., 2021 ). Some of the dwarf genes are closely related to hormone signal pathways, like gibberellin (GA), brassinosteroids (BRs), auxin (IAA) and/or strigolactone (SLs) ( Itoh et al., 2004 ; Lin et al., 2009 ; Hirano et al., 2010 ; Tong et al., 2010 ; Sun, 2011 ; Yang et al., 2011 ; Li et al., 2014 ; Zhou et al., 2015 ; Li et al., 2018b ; Zhao et al., 2019 ; Roy et al., 2021 ; Su et al., 2022 ; Xu et al., 2022 ).…”

“…The sdf-1 locus was mapped to an 80.72 kb region on Chr 19 of soybean ( Dong et al., 2020 ). GmIAA27 relies on auxin to interact with TIR1, and control a dmbn mutant plants ( Su et al., 2022 ). The challenge of genetic dissection of the dwarf in soybean may result from palaeopolyploid, which makes dwarf gene identification in soybean more complicated.…”

Auxin regulation on crop: from mechanisms to opportunities in soybean breeding

“…Among this QTL interval, 8 candidate genes including an auxin response factor 9 (ARF9), a SAUR family gene, and an AUX in ux permease are components of auxin signaling or auxin transport (Jiang et al 2018). A dwarf soybean mutant named dmbn was identi ed from ethyl methanesulfonate (EMS)mutagenized soybean seeds, and the dwarf phenotype might be associated with an auxin signaling regulator, Aux/IAA protein GmIAA27 (Su et al 2022). Furthermore, the cytokinin response factors 4a (GmCRF4a) promotes cell elongation and shoot height in soybean, as GmCRF4 is required for GmYUC expression which controls auxin biosynthesis (Xu et al 2022).…”