Transgenic carrots with enhanced resistance against two major pathogens, Erysiphe heraclei and Alternaria dauci

In vitro assay indicated that the human lysozyme has lytic activity against phytopathogenic fungi and bacteria. A human lysozyme gene was placed under control of the constitutive CaMV 35S promoter and the resulting expression plasmid was introduced into two cultivars (cv.) of carrot, Kurodagosun (K5 ) and Nantes Scarlet (NS), by Agrobacterium tumefaciens-mediated method. Se ven and fourteen transgenic plants of cv. K5 and cv. NS were regenerated, r espectively, and the obtained transgenic carrots of T0 generation was teste d for disease resistance against Erysiphe heraclei, a pathogenic fungi caus ing powdery mildew. Among the tested lines, the transgenic plant No. 12-1 a nd 8-1 of cv. NS showed a fairly strong resistance against E. heraclei. The strong disease resistance was also confirmed in T1 generation. Disease res istance against another pathogen of leaf blight, Alternaria dauci, were als o tested using T1 transgenic lines. Significant enhanced resistance was obs erved in the No. 12-1 of cv. NS. Accumulation of synthesized human lysozyme protein was observed in this line, a finding consistent with observed dise ase resistance. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.