Abstract:

Receptor like protein kinases (RLKs) play vital roles in both plant development and stress conditions. Using drought-treated "Yugu 1" as materials, a drought-responsive RLK gene, SiRLK35, was isolated through iTRAQ analysis. In this study, the further analyses of the gene functions were carried out. First, full-length SiRLK35 was amplified by PCR using the cDNA of foxtail millet seedlings as a template. The expression patterns of SiRLK35 under NaCl, PEG, ABA, GA and MeJA treatment were analyzed by quantitative real-time PCR (qRT-PCR), and we found that the expression of SiRLK35 could be induced under different treatments, especially under NaCl treatment. Second, the prokaryotic expression plasmid of SiRLK35 was constructed, and the salt resistance of SiRLK35 was detected by the bacterial plaque growth method. And we uncovered that the growth and tolerance of SiRLK35-containing Escherichia coli strains were in better conditions than control under the NaCl stress. Lastly, pCambia1301P-SiRLK35 was constructed and transformed into rice to obtain transgenic plants. The tolerance of transgenic rice plants to salt stress was higher than that of controls through physiological analysis. We propose that SiRLK35 may participate in salt and stress resistance processes, which could provide potential theoretical foundation for the stress resistance varieties cultivation and breeding of foxtail millet.

Key words: Setaria italica L., receptor like protein kinase, expression pattern, salt and stress resistance, varieties cultivation and breeding