Cloning and Expression Analysis of Shade responsive Gene GmIF-3 in Soybean

PurposeCloning and expression analysis of shade responsive gene GmIF-3 in soybean.

MethodPhosphoproteomics was used to analyze the phosphorylation status of soybean total proteins under the shading stress. We screened out an IF-3 (translation initiation factor) protein whose phosphorylation was significantly elevated in the shade and its encoding gene was named as GmIF-3 (Glyma.17G072300). Bioinformatics was used to analyze its gene structure and biochemical properties such as promoter sequence, protein structure and protein hydrophobicity. The cDNA sequence was cloned by Gateway^® cloning. Real-time quantitative PCR was used to detect its tissue expression pattern and expression under shading treatment.

ResultsBioinformatics analysis showed that GmIF-3 is located on soybean chromosome 17, which encodes a protein of 274 amino acid residues with a protein isoelectric point of 9.11 and a molecular weight of 30.83 ku. Its promoter contains multiple light and hormonal response cis-acting elements. The cDNA sequence was then amplified by RT-PCR. Real-time quantitative PCR showed that the relative expression of GmIF-3 gene was the highest in unifoliolate leaves. It is also expressed in various organs such as trifoliolate leaves, shoot apical meristems, roots, stems, petioles, cotyledons, flowers and pods. The expression of GmIF-3 in the seedlings was significantly upregulated as time increase from 0 to 1, 2, 4 and 6 h under shade stress, and reach the highest level at the 6^th h, which is about 8.3 times higher than that in the control (at 0 h).

ConclusionThe GmIF-3 gene may be involved in the response of soybean to shading stress.