In situ localization of mRNA of resembling the dirigent protein in sugarcane stems

Background The dirigent proteins (DP) families and resembling the DP (DP-like) are exclusive in land plants and related to plants defense and forming phenylpropanoids compounds optically active, mainly pinoresinol [1]. Pinoresinol is converted into a variety of lignans. The dirigent protein involvement is not confirmed in lignin formation, a biopolymer which is a negative factor for the ethanol cellulosic production. However, recently it was demonstrated Arabidopsis DP-like, AtDIR10, localization in the lignin polymerization site and a determinant role in the formation of a lignin specific root structure, named as Casparian strip [2]. Despite of the controversy of the DP forming-lignin its substrate diversity is consistent. Since DPs and DPs-like are represented by numerous members of gene families with high diversified sequences and with unknown functional role for most of them [3]. One of the sugarcane DP-like, named as ShDP1-like, showed special interesting due its high level of expression in the pith of mature stem [3] coinciding with higher level of the sinapyl (S) unit forming lignin [4]. Localization of DP expression to particular cell and tissue types is a necessary prerequisite in understanding the biological role of this gene.