Cloning of SCA Gene Related to Pollen Tube Adhesion and Oriented Growth and Analysis of Gene Diversity in <i>Lilium spp.</i>

Abstract

Stigma/style cysteine-rich adhesin genes ( SCA ) were cloned from ‘Tresor’ ( Lilium Asiatic Hybrids), ‘White heaven’ ( Lilium Longiflorum Hybrids) and ‘Caruso’ ( Lilium Oriental Hybrids) leaves by PCR approaches. In this research we obtained four gene copies in both of ‘Tresor’ and ‘Caruse’ genomes and three gene copies in ‘White heaven’ genome. The identities of the cloned SCA among the copies were in the ranges from 72.97% to 99.68%. There are two exons and one intron in all of cloned SCA sequence, which could be deduced immature protein with 113 or 115 amino acid residues (encoding mature protein with 91 amino acid residues) SCA protein contains an N-terminal signal peptide of typical LTP protein, eight conserved cysteine residues and two consensus pentapeptide motifs. The identities among the amino acid sequences were in range from 87.91% to 98.90% higher than that of the similarities of gene sequences. Alignment analysis of amino acid sequences of cloned SCAs showed there were some distinct differences of amino acid site existing in the tested three species of lily hybrids. The phylogenetic tree revealed the relationship of the cloned 11 amino acid sequences of SCA were all more close to LTP family of monocotyledons than that of dicotyledons, which were consistent with the conclusions of kinship in plant taxonomy.