Molecular Cloning and Expression of HbMKK4 from Hevea brasiliensis(Para Rubber Tree)

In this work,the full length cDNA of HbMKK4 was obtained from cDNA library in latex of rubber tree clone‘CATAS 7-33-97'by RACE.It was 1 580 base pair(bp)in length,containing a 1 059 bp open reading frame(ORF)which encodes 352 amino acid with a predicted molecular mass of 38.83 kD and pI 9.36.The deduced amino acid sequence contain S_TKc domain.Comparing expression among different tissues showed that HbMKK4 was expressed in root,bark,latex and leaves.HbMKK4 transcript levels were significantly upregulated in latex by tapping,methyl jasmonate and ethephon treatment for rubber tree.The transcript levels peaked in 2hours by tapping,8hours by methyl jasmonate and 4hours by ethephon treatment,respectively.These results suggested that HbMKK4,a member of MAPK cascade,might plays a role in rubber biosynthesis via JA pathway in rubber tree.