Abstract:

The availability of sorghum genome makes it possible to perform the genomewide analysis of the expression profile of MAPKs genes in Sorghum bicolor under the stresses of NaCl and Na2CO3 so as to explore the MAPKs involvement into salinealkali signaling pathway. The results show that 16 MAPKs genes were dentified from the genome of Sorghum bicolor, namely SbMPKs, and their expression profiles under the stresses of NaCl and Na2CO3 differ from each other significantly. This suggests that neutral saltinduced signal response may differ from that induced by alkaline salt. Under the stress of NaCl, all SbMPKs were upregulated continuously during 24 h except the SbMPK13 whose expression reached to the maximum at 12 h. Under the stress of Na2CO3, however, only SbMPK3,SbMPK10 and SbMPK13 were upregulated, implying that  SbMPKs are likely responsible specifically for alkaline salt stress in sorghum. P
hylogenetic analysis classified SbMPK13 into the C group of MAPKs,  which is similar toOsMAPK2 that  is responsible to ABA and salt stress in rice, further confirming that it is involved possibly in the regulation of salt stress response genes in sorghum.

Key words: Sorghum bicolor, MAPKs gene, expression pattern, computational identification, salinealkali stress