Biotechnology Bulletin ›› 2023, Vol. 39 ›› Issue (3): 123-132.doi: 10.13560/j.cnki.biotech.bull.1985.2022-0819

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Isolation and Expression Analysis of SiMAPK3 in Setaria italica L.

WANG Hai-long1(), LI Yu-qian1,2, WANG Bo3, XING Guo-fang2(), ZHANG Jie-wei1()   

  1. 1. Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097
    2. College of Agriculture, Shanxi Agricultural University, Taigu 030801
    3. College of Life Sciences, Yantai University,Yantai 264005
  • Received:2022-07-02 Online:2023-03-26 Published:2023-04-10

Abstract:

Mitogen-activated protein kinases(MAPKs)are a class of serine/threonine protein kinases that play important roles in plant growth and development, response to stress, and hormone signal transduction. In this study, the SiMAPK3 gene, which was the highest protein homology to AtMAPK3 in Arabidopsis, was cloned from the foxtail millet variety Yugu 1. The physicochemical properties, structure and function of SiMAPK3 protein were systematically analyzed by bioinformatics methods. The expressions of SiMAPK3 gene in different tissues and different abiotic stress in the early shooting stage of the foxtail millet was analyzed by RT-qPCR. The results showed that the open reading frame of SiMAPK3 gene was 1 128 bp, encoding a deduced protein of 376 amino acids, with a predicted molecular weight of 43 427.85 Da and an isoelectric point of 5.46. The SiMAPK3 in the foxtail millet was a hydrophilic extramembrane protein without signal peptide. Its secondary structure included 44.27% α helix, 14.67% β sheet, 5.07% extended chain and 36.00% random coil. SiMAPK3 amino acid 44-328 contained a Pkinase conserved domain, belonging to the MAPK protein kinase family. The tertiary structure of SiMAPK3 had high similarity with Arabidopsis MAPK protein, SiMAPK3 contained 11 serines, 8 threonines, 4 tyrosines and a large number of potential phosphorylation sites. Protein structural analysis showed that it had a conserved PKinase domain. RT-qPCR analysis showed that SiMAPK3 was expressed in the roots, stems and leaves of foxtail millet in the early shooting stage, and its expression level was the highest in leaves, which was about 25 times that in roots. SiMAPK3 responded to low temperature(4℃), high salt(300 mmol/L NaCl), drought and ABA(200 μmol/L)and JA(200 μmol/L)and other stresses. After 12 h of low temperature, the expression of SiMAPK3 was up-regulated 16-fold, and after 3 h of high-salt, the expression of SiMAPK3 was up-regulated 8-fold. The cloning and functional analysis of the SiMAPK3 gene provide an important basis for further analysis of the leaves development and the signal transduction in response to low temperature and high salt in foxtail millet.

Key words: Setaria italica, SiMAPK3, leaf development, cold stress, salt stress, ABA, JA, drought stress