Brassinolides promote the expression of a new Cicer arietinum tubulin gene involved in the epicotyl elongation

Abstract

A cDNA clone, CanTUB, encoding a putative tubulin protein was isolated from a cDNA library constructed from 5day old chickpea (Cicer arietinum) epicotyls. Analysis of its deduced amino acid sequence showed all the typical structural motifs of plant tubulins. Putative sequences for autoregulation and tubulin mRNAstability, GTP and Ca2+/MAPs (microtubuleassociated proteins) binding sites were present. Southern blot analysis of chickpea genomic DNA revealed that there are multiple tubulin genes. The level of expression of tubulin genes was correlated with the rate of growth in either seedlings and adult plants. The transcript levels of tubulin genes were higher in actively elongating tissues such as etiolated epicotyls, roots and stem tissues of adult plants. Brassinolideinduced growth in chickpea epicotyls was accompanied by promotion of the expression of the gene coding for tubulin.