Functional Characterization of the Steroid Reductase Genes GmDET2a and GmDET2b from Glycine max

Abstract

Brassinosteroids are important phytohormones for plant growth and development. In soybean (Glycine max), BR receptors have been identified, but the genes encoding BR biosynthesis-related enzymes remain poorly understood. Here, we found that the soybean genome encodes eight steroid reductases (GmDET2a to GmDET2h). Phylogenetic analysis grouped 105 steroid reductases from moss, fern and higher plants into five subgroups and indicated that the steroid reductase family has experienced purifying selection. GmDET2a and GmDET2b, homologs of the Arabidopsis thaliana steroid 5α-reductase AtDET2, are proteins of 263 amino acids. Ectopic expression of GmDET2a and GmDET2b rescued the defects of the Atdet2-1 mutant in both darkness and light. Compared to the mutant, the hypocotyl length and plant height of the transgenic lines GmDET2a and GmDET2b increased significantly, in both darkness and light, and the transcript levels of the BR biosynthesis-related genes CPD, DWF4, BR6ox-1 and BR6ox-2 were downregulated in GmDET2aOX-23 and GmDET2bOX-16 lines compared to that in Atdet2-1. Quantitative real-time PCR revealed that GmDET2a and GmDET2b are ubiquitously expressed in all tested soybean organs, including roots, leaves and hypocotyls. Moreover, epibrassinosteroid negatively regulated GmDET2a and GmDET2b expression. Sulfate deficiency downregulated GmDET2a in leaves and GmDET2b in leaves and roots; by contrast, phosphate deficiency upregulated GmDET2b in roots and leaves. Taken together, our results revealed that GmDET2a and GmDET2b function as steroid reductases.

Genome-wide Association Study for Yield and Yield-Related Traits in Diverse Blackgram Panel (Vigna mungo L. Hepper) Reveals Novel Putative Alleles for Future Breeding Programs

“…The enzymes encoded by genes found for QTLs of PHM were involved in controlling the plant height as supported by earlier studies of enzyme E3 ubiquitin-enzyme ligase MARCH1 in rice ( Hu et al, 2013 ), bZIP transcription factor 53 in soybean ( Ali et al, 2016 ), enzyme trichome birefringence-like six in Rice ( Gao et al, 2017 ), histone-lysine N-methyltransferase EZ2-like ( https://www.uniprot.org/uniprot/O23372 ), DELLA enzyme RGL1-like in Arabidopsis ( Serrano-Mislata et al, 2017 ), DEAD-box ATP-dependent RNA helicase 24 in rice ( Wang et al, 2016 ), probable WRKY transcription factor 23 in rice ( Cai et al, 2014 ), gibberellin 2-beta-dioxygenase two in Arabidopsis ( Rosin et al, 2003 ), transcription factor JAMYB-like in rice ( Zhang et al, 2017 ), acyl transferase four in rice ( Basu et al, 2017 ), tropinone reductase homolog ( Stead, 1989 ), in grapevine ( Guillaumie et al, 2020 ), steroid 5-alpha-reductase DET2 in soybean ( Huo et al, 2018 ), squamosa promoter-binding-like enzyme 14 in rice ( Lu et al, 2013 ), cytochrome P450 71D11 in cucumber ( Wang et al, 2017 ), pentatricopeptide repeat-containing enzyme At3g48810 in Arabidopsis ( Lee et al, 2019 ), and pentatricopeptide repeat-containing enzyme At1g31430 in Arabidopsis ( Lee et al, 2019 ).…”

Ectopic expression of GmNF-YA8 in Arabidopsis delays flowering via modulating the expression of gibberellic acid biosynthesis- and flowering-related genes and promotes lateral root emergence in low phosphorus conditions

“…Nutrient solutions were aerated 15 min every 3h, and replaced with fresh nutrient solutions every 2 days. As described ( Huo et al., 2018 ), Arabidopsis seeds were sterilized with 75% ethanol for 2 minutes followed by 100% ethanol for 2 minutes. Then seeds were sown on half strength MS media containing 1% sucrose and 0.8% agar (pH 5.8).…”

Regulation of Brassinosteroid Homeostasis in Higher Plants

“…A steroid 5α-reductase, named as DEETIOLATION 2 (DET2), is responsible for the C5 reduction in Arabidopsis ( Chory et al, 1991 ; Li et al, 1996 ; Fujioka et al, 1997 ; Li et al, 1997 ; Noguchi et al, 1999 ). Paralogs of DET2 in different plant species have also been identified, such as in soybean, cotton, cucumber, pea, and morning glory ( Suzuki et al, 2003 ; Nomura et al, 2004 ; Luo et al, 2007 ; Hou et al, 2017 ; Huo et al, 2018 ).…”