| Agglutinins are proteins possessing at least one noncatalytic domain, which binds reversibly to specific mono- or oligo- saccharides. Among them a sub family represented by Galanthus nival is agglutinin (GNA) is characterized with effective resistance activity against Homopteran insects, while another subfamily represented by gastrodianin is more effective against pathogenic fungi, with both of the subfamily showing great potential application in plant resistance improvement against insects or fungal pathogens.To seek more effective genes with insect resistance or anti-fungal activities, agglutinin genes including zaa, doa and zoa were successfully isolated from Zantedeschia aethiopica, Dendrobium officinale and Zingiber officinale by using rapid amplification of cDNA ends (RACE)-PCR method respectively, and their functions were also studied. The results are as follows:1. The full-length cDNA of zaa gene was cloned firstly from Z. aethiopica., which belongs to Araceae family. The full-length cDNA of zaawas 871bp with an opening reading frame of -il7bp encoding a protein with 138 amino acids. Sequence homology analysis was also carried out among ZAA and other monocot mannose-binding agglutinins. Southern blotting results revealed that zaa was encoded by a multiple gene family. Semi-quantitative RT-PCR analysis revealed that zaa mRNA expression could be detected in all the tested tissues among with the highest expression being found in petiole.2. The promoter region, terminator region and the genomic sequence of zaa were also cloned. The core promoter, basic active motif, motif related to anti-disease and other motifs within promoter region were analyzed. The terminator was rich in A+T and it formed a stem structure, which was the typical feature of terminator.3. A plant expression vector pCAMBlA1304-zaa containing zaa gene was constructed and introduced into Agrobacterium tumefaciens strain EHA105.
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