The Potential Role of PeMAP65-18 in Secondary Cell Wall Formation in Moso Bamboo

Microtubule-associated proteins (MAPs) play a pivotal role in the assembly and stabilization of microtubules, which are essential for plant cell growth, development, and morphogenesis. A class of plant-specific MAPs, MAP65, plays largely unexplored roles in moso bamboo (<i>Phyllostachys edulis</i>). This study identified 19 <i>PeMAP65</i> genes in moso bamboo, systematically examining their phylogenetic relationships, conserved motifs, gene structures, collinearity, and <i>cis</i>-acting elements. Analysis of gene expression indicated that <i>PeMAP65</i>s exhibit tissue-specific expression patterns. Functional differentiation was investigated among the members of different <i>PeMAP65</i> subfamilies according to their expression patterns in different development stages of bamboo shoots. The expression of <i>PeMAP65-18</i> was positively correlated with the expression of genes involved in secondary cell wall (SCW) biosynthesis. Y1H and Dual-LUC assays demonstrated that the transcription of <i>PeMAP65-18</i> was upregulated by PeMYB46, a key transcription factor of SCW biosynthesis. The result of subcellular localization showed that PeMAP65-18 was located in cortical microtubules. We speculate that <i>PeMAP65-18</i> may play a crucial role in the SCW deposition of moso bamboo. This comprehensive analysis of the MAP65 family offers novel insights into the roles of <i>PeMAP65</i>s in moso bamboo, particularly in relation to the formation of SCWs.