Abstract: Sucrose nonfermenting 1 protein kinase is the key enzyme in the process of carbon source metabolic derepression. For this, the location of StSNF1 in genome, the protein structural characteristics of StSNF1, the expression level of StSNF1 at different infection stages in maize, different stages in the conidial invasive growth of Setosphaeria turcica and under the different carbon sources were studied. The results showed that the Gene ID number was 008026214, length was 3 046 bp, located between 97 793 and 100 838 in the antisense strand of scaffold_17 in the genome of S. turcica. The StSNF1 protein was more closely related to Cochliobolus carbonum SNF1, and encoded by 877 amino acid residues. StSNF1 showed characteristic conserved domains of protein kinase, carbon catabolite-derepressing protein kinase at N-terminal and a kinase associated domain 1 at C-terminal. An ATP binding site and a serine/threonine active site were found in the protein kinase domain. The results of Real-time PCR indicated that the expression of StSNF1 was significantly up-regulated in late stage of infection, especially at 72 h. The expression trends of StSNF1 was up-regulated during the conidia germination.The highest expression of StSNF1 was found in the medium that sucrose as the sole carbon source followed by pectin. All the results suggested StSNF1 was closely related to the infection and the carbon source utilization. Moreover, in the late stage of infection, the intracellular non-fermentable carbon sources of host were used in secondary infection.

Key words: Setosphaeria turcica, SNF1, Protein kinase, Expression analysis

CLC Number: 

• S513.03

• Q78