Isolation and expression of a barley beta-1,3-glucanase isoenzyme II gene.

A beta-1,3-glucanase gene from Hordeum vulgare was isolated by a PCR strategy, cloned and subsequently sequenced. The amplified sequence contained the entire coding region of the isoenzyme II, which is interrupted by a 165 bp intron at 73 bp downstream the starting codon. This intron contains all the elements required for the processing mechanism in monocots: a high A + U content, the appropriate splice sites in the 5' and 3' ends and four typical YUNAN consensus sequences. Transient transformation of wheat protoplasts with the complete beta-1,3-glucanase gene under the control of maize polyubiquitin promoter revealed that the intron sequence was spliced out. The gene was also expressed at high levels, probably due to an enhancer-like sequence found near the 3' end of the intron.