MF2 and MF3 applied individually or in combination against tobacco mosaic virus on tobacco leaves

Abstract

Proteins inducing plant resistance to diseases represent a promising base for plant protection in organic agriculture. We identified and studied two promising proteins, a cold shock protein from Bacillus thuringiensis (MF2) and a FKBP-type peptidyl prolyl cis/trans isomerase from Pseudomonas fluorescens (MF3). Structures of these proteins and their active centers responsible for their protecting activity are different suggesting they may have different targets in plant tissues and their combined action may improve the plant protection against various pathogens including plant viruses. To examine this hypothesis, the protective effect of MF2, MF3, and their combination against tobacco mosaic virus (TMV) was compared on detached tobacco leaves. Each of the proteins was applied on one leaf half, while the mix of equal volumes of MF2 and MF3 solutions was applied on the second half. The final concentration of each protein in the mix was twice lower than in individual solutions. The MF1+MF2 mix more efficiently reduced the number of TMV-induced leaf necroses than individual proteins taken at twice higher concentrations. This fact may evidence good prospects for the development of a hybrid protein or polypeptice based on MF2 and MF3 or their active centers as a basis for plant-defence-inducing preparations.