THE PROMOTER OF A GENE ENCODING A POLYGALACTURONASE-INHIBITING PROTEIN OF PHASEOLUS-VULGARIS L. IS ACTIVATED BY WOUNDING BUT NOT BY ELICITORS OR PATHOGEN INFECTION

Polygalacturonase-inhibiting proteins (PGIPs), leucine-rich repeat (LR R) proteins evolutionarily related to several plant resistance genes, bind to and regulate the action of fungal endopolygalacturonases. In P haseolus vulgaris L., PGIPs are encoded by a gene family comprising at least five members. As a start for a systematic analysis of the regul ation of the pgip family, we have analysed the ability of the promoter of the bean gene pgip-1 to direct expression of beta-glucuronidase (G US) in transfected tobacco protoplasts, microbombarded bean and tobacc o leaves, and transgenic tobacco plants. In protoplasts, the pgip-1 ge ne region from nucleotide (nt) -2004 to nt -t27 directed a level of ex pression that was as high as that directed by the cauliflower mosaic v irus (CaMV) 35S promoter and could not be further induced by elicitor treatment; alteration of the region immediately following the TATAA se quence at nt -29 abolished expression. Upon stable integration into to bacco plants of the pgip-1 promoter-GUS construct, as well as of a -39 4 deletion, expression was detected for both constructs mainly in the stigma and, to a lesser extent, in the anthers and in the conductive v ascular tissue. The promoter responded to wounding but not to oligogal acturonides, fungal glucan, salicylic acid, cryptogein, or pathogen in fection. This expression pattern does not mirror that of the whole pgi p gene family.