Figure 4From: Yeast functional screen to identify genetic determinants capable of conferring abiotic stress tolerance in Jatropha curcasYeast transformants expressing genes derived from J. curcas root library. Photographs of representative replica plate screen (as described in Figure 3) demonstrating the ability to isolate yeast transformants during salinity stress. Yeast transformants (selected for plasmid borne URA3 marker), expressing genes derived from J. curcas root libraries, showing tolerance to stress induced by 750 mM NaCl are marked in panel D (black circles). Identical yeast transformants, (compare panel B to D) with repressed gene expression shows arrested growth. (A) describes control conditions where gene is repressed and stress is not provided to the yeast cells. Yeast transformants are expected to grow on synthetic selection plates with dextrose as the carbon source. Transformants in type (B) conditions (to identify false-positives) are grown in synthetic selection media with dextrose as the carbon source, but treated under stress conditions. In these plates all transformants are expected to show retarded growth, due to the stress conditions. In type (C) conditions, yeast transformants are grown on synthetic selection plates containing galactose, but without subjecting them to stress conditions. If the expression of any heterologous gene is detrimental to cell grown, it can be identified, thus eliminating recovery of false-negative transformants in the screen. In type (D) conditions, where the gene expression is induced by galactose and the cells are simultaneously subjected to stress, yeast transformants that are capable of survival under stress (acquired due to expression of J. curcas heterologous cDNA) are able to grow (Figure 3).Back to article page