Cloning and Expression Analysis of an Alkaline/Neutral Invertase Gene in Hevea brasliensis
Based on the Hevea EST and genome sequence database,we cloned one alkaline/neutral invertase gene,HbNINa,which was highly expressed in the leaf of Hevea brasiliensis.Sequence analysis revealed that HbNINa coding sequence was 1 719 bp,and the deduced peptide was 571 amino acids in length,with an average molecular weight of 65.7 ku and a pIvalue of 6.36.The HbNINa protein contained all the conserved domains of typical plant alkaline/neutral invertases.Exon/intron structure analysis showed that the HbNINa gene contained four exons and three introns.The real-time RT-PCR results indicated that the HbNINa expression was mainly found in the bark,leaf and female flower,whereas barely detectable in the latex.HbNINa was also found highly expressed in bronze-stage leaf and down-regulated with leaf maturation,suggesting the important roles of this gene in the process of leaf maturation in rubber tree.