ABSTRACT
Thus, some RIPs inactivate host conspecific ribosomes, while others exhibit toxicity toward ribosomes from distantly related species, including animals and fungi.
In cases where a RIP may inactivate conspecific ribosomes, the protein is usually synthesized as an inactive precursor or is targeted out of the cytoplasm, usually extracellularly. Because of their potential toxicities, two major functions are postulated for RIPs. First, RIPs which inactivate conspecific ribosomes may function as inducible or developmentally programmed suicide genes. Second, RIPs which inactivate phylogenetically distant ribosomes may have defensive functions in protecting plants from herbivores or pathogens. The potential utility of either role has led to work to elucidate their function and to
exploit their varied toxicities. Thus, work has been done on the potential of RIPs to increase the protection of plants against pathogens.
