THE GOAL OF THIS PROJECT IS TO USE INDUCIBLE PLANT REGULATORY SEQUENCES FOR THE CONTROLLED EXPRESSION OF 2 USEFUL GENETIC PROPERTIES :
- THE CONSTRUCTION OF RESISTANCE GENES WHICH COULD BE SWITCHED ON AFTER FUNGAL INFECTIONS, THEREFORE REDUCING THE DEPENDENCE ON CHEMICAL FUNGICIDES.
- THE USE OF "STRESS BOX" TO SWITCH ON THE PRODUCTION PHASE OF CELL CULTURES ENGINEERED FOR THE SYNTHESIS OF A GENE PRODUCT IN MASSIVE AMOUNTS.
Research was carried out in order to develop a gene expression system based on the flavonoid specific chalcone synthase (chs) genes from petunia and soybean chs is involved in flower pigmentation (in petunia) and phytoalexin synthesis (in soybean). Primary approaches include: isolation of chs genes, analysis of chs genes, analysis of tissue specific expression, construction of chimaeric genes (gus, CAT, NPTII), promoter deletion analysis in transient expression systems and stable transformants. These findings will extend understanding of the factors that control gene expression in higher plants.
10 chs genes were cloned from petunia and sequenced. chsA and J contribute 90 and +/- 10% to the chs messenger ribonucleic acid (mRNA) level, respectively. Both are flower specific, gibberellic acid (GA) sensitive and in young seedlings and tissue cultures inducible by ultraviolet (UV) light. Unexpectedly, expression of chsA and J was also found in reproductive tissues and seeds. In chsJ-gus functions, the chs promoter remained GA-inducible in flowers and UV-inducible in plantlets. By deletion analysis it was shown that a promoter as short as 100 nucleotides was still UV-inductible and flower specific. 3 soybean chs genes were characterized. Only chs1 was found to be UV-inducible and elicitor inducible in soybean seedlings, whereas in cell culture all chs genes were elicitor inducible. Promoter deletion analysis of ch1-gus fusions in transient expression systems of soybean and parsley protoplasts showed that sequences up to -178 were needed to confer elicitor inducibility in both systems and UV inducibility in parsley.
THE AIM OF THIS PROJECT IS TO DEVELOP INDUCIBLE GENE EXPRESSION SYSTEMS WITH A WIDE HOST RANGE FOR PLANTS AND PLANT CELL CULTURES. THIS SYSTEM WILL BE DIRECTLY TESTED BY GENERATING PATHOGEN-RESISTANT SOYBEAN LINES (CONTRIBUTION KOLN) AND BY IMPROVING PRODUCTIVITY IN CELL SUSPENSION CULTURES)(CONTRIBUTION AMSTERDAM). THE QUESTIONS TO ANSWER WILL BE : WHAT IS THE MOLECULAR MECHANISM OF THE INDUCTION OF GENE EXPRESSION BY STRESS (TEMPERATURE SHOCK, FUNGAL ELICITOR) IS IT POSSIBLE TO CONSTRUCT CHIMERIC GENES, THE EXPRESSION OF WHICH WILL BE STIMULATED BY STRESS WILL STRESS INDUCTION WORK IN A BROAD RANGE OF TRANSFORMED SPECIES.
Funding SchemeCSC - Cost-sharing contracts