Expression Of Calcium Dependent Protein Kinase Genes In The Process Of Banana Infected By Fusarium Oxysporum F. Sp. Cuhense Tropical Race 4

CDPK (Calcium Dependent Protein Kinases) is a kind of serine/threonine kinase widespreaded in the plant kingdom, playing a key role in Ca2+signaling processes, and being involved in plant response to various biotic and abiotic stresses. The present study is based on the results of banana (Musa acuminata L. AAA group cv. Brazilian) roots in response to Fusarium oxysporum f. Sp. Cubense Tropical Race 4 (Foe TR4) infection. There were 13 CDPK high homology cDNA sequence in the transcriptome data. And then, using RACE technology to acquire 9 MaCDPK full-length genes, which were named:MaCDPKl, MaCDPK2, MaCDPKS, MaCDPK4, MaCDPKS, MaCDPK6, MaCDPK7,MaCDPK8, and MaCDPK9. Through PROSITE analysis, they owned the conserved structural domains: N-terminal variable region of the catalytic zone, the connecting region and the regulatory region. In bananas A genome database, highly homologous sequences were found corresponding with MaCDPK1-9. The research aims were to find the function of the MaCDPK1-9 in the banana responding to Foc TR 4 infection by Q-PCR in different treatments. The results are as follows:1 MaCDPK1-9 genes expressed in all organs of banana, such as roots, corms, pseudo stem, leaf, flower, fruit. But the expressions of nine genes were different, indicating that these nine genes may play different roles in organ development.2. Fusarium wilt of banana was caused by Foc TR4, which was a soil-borne fungi. In the inoculation Brazilian banana roots, the expression level of MaCDPKl, MaCDPK2, MaCDPK3, MaCDPK5, MaCDPK6 and MaCDPK8 were increased, MaCDPK4, MaCDPK1 and MaCDPK9 were decreased. All of these results were consistent with the DGE results.3. The expression of MaCDPK1-9 in the varieties of Nongke NO.1 were higher than susceptible varieties Brazil banana. MaCDPKl, MaCDPK3, MaCDPK5 and MaCDPK6 may be involved in the process of banana resistant to Fusarium wilt.4. The experimental studies have demonstrated that exogenous salicylic acid on banana Foc TR4 disease resistance (results to be published). MaCDPK1-9 were induced by exogenous salicylic acid, but after inoculation of Foc TR4 MaCDPK1-9 expression patterns relative to the Brazilian banana inoculated with FOC TR4 expression pattern has not changed obviously, so MaCDPK1-9 may not be involved in the dependence of salicylic acid resistance to Fusarium wilt ways.5. The expression of MaCDPK1-9 were changed by treatment with and EGTA, but the expression patterns were different, so the result indicated that different MaCDPK was required for different concentration of calcium to regulate downstream pathways.The above results show that MaCDPK may be involved in the banana in response to Foc TR4 process. All MaCDPKs were induced by exogenous salicylic acid, but MaCDPK may not participate in the process mediated by depending on salicylic acid resistance to Fusarium wilt of banana.