Development of Virus Resistance in Plants
Using Ribosome-Inactivating Protein (RIP) Genes

Systematic acquired resistance (SAR) is a general approach in plant protection. One angle of this approach is protein engineering of Ribosome-Inactivating Proteins (RIPs) and encoded genes in plant defense.

RIPs are a group of plant enzymes which inactivate most of animal ribosomes and some plant and bacterial ribosomes, thus arresting protein synthesis. They are classified into two groups,
type 1: single-chain polypeptide & type 2: two chains proteins consisting of an A-chain with enzymatic activity equivalent to the type 1, and a B-chain with lectin properties. Their enzymatic activity was recently identified as a unique N-glycosidase that hydrolyzes a specific N-glycosidic bond (A4324 of 28 S rRNA in case of rat liver).

These proteins have been isolated from different plants, such as soapwort, corn cokle, asparagus, sandbox, wheat and others. Also the genes which encoded these proteins were isolated from castor bean and trichosanthes.

RIPs proteins have similar physico-chemical properties, show family-related homologies in their amino acid sequences. They have potential utilization in agriculture for their toxicity to pests, activity and in human therapy. Accordingly we plan to isolate and characterize these proteins and their genes from some wild type plants.

OBJECTIVES

•  Study the occurrence of RIP proteins and encoded genes in certain wild-type plants for their economic importance against many plant diseases.

•  Extraction, chemical and biological characterization of these proteins and encoded genes will be carried out.