大豆耐铝毒候选基因 GmSTOP1 的克隆与表达分析

Aluminum toxicity is one of the major factors that limits the growth and production of crops in acid soils. AtSTOP1 transcription factor can regulate the expression of genes related to aluminum-toxicity tolerance mechanisms, which plays an important role in aluminum-toxicity tolerance in Arabidopsis. To study the expression features of the STOP1-like gene in soybean, we cloned a STOP1 gene located on chromosome 16 from the aluminum-toxicity tolerant soybean cultivar (Kefeng-1) using RT-PCR, and designated as GmSTOP1. The length of GmSTOP1 coding DNA sequence was 1566 bp, which encoded 521 amino acid residues. Diverse cis-acting promoter elements involved in hormone, heat and stress responses were discovered in the 1500 第 12期 丛亚辉等: 大豆耐铝毒候选基因 GmSTOP1的克隆与表达分析 1803 bp upstream region of GmSTOP1, such as ABRE, HSE, TC-rich repeats, and other elements. Protein structure prediction showed that it did not have any signal-peptide or transmembrane region, but contained four conservative Cys-2-His-2 zinc-finger domains. Phylogenetic analysis demonstrated that GmSTOP1 was similar to the putative STOP1-like protein from Phaseolus vulgaris. Results of subcellular localization showed that GmSTOP1 protein is located in the cell nucleus. The transcripts of GmSTOP1 were detected in all organs tested including root, shoot apical meristem, stem, leaf, flower, pod and seed, with the highest level in seed. GmSTOP1 was up-regulated in soybean roots by 25 μmol L AlCl3 treatment, and reached the highest relative expression level at 24 hours, which was about 9.2 times of the level in control (0 μmol L AlCl3). In addition, Real-time PCR analysis showed that the expression of GmSTOP1 in soybean leaf and root was also up-regulated by ABA, NaCl, and PEG, respectively. These results indicated that GmSTOP1 might participate in soybean response to abiotic stresses including aluminum-toxicity, high salinity and osmosis stress, which provides the basis for further studying the functions of GmSTOP1.