Gain-of-function in Arabidopsis (GAINA) for identifying functional genes in Hevea brasiliensis

Forward genetics approaches are not popularly applied in non-model plants due to their complex genomes, long life cycles, backward genetic studies etc. Researchers have to adopt reverse genetic methods to characterize gene functions in non-model plants individually, the efficiency of which is usually low.

In this study, we report a gain-of-function in Arabidopsis (GAINA) strategy which can be used for batch identification of functional genes in a plant species. This strategy aims to obtain the gain-of-function of rubber tree genes through overexpressing transformation ready full-length cDNA libraries in Arabidopsis. An initial transformation test produced about two thousand independent transgenic Arabidopsis lines, in which multiple obvious aberrant phenotypes were observed, suggesting the gain-of-function of rubber tree genes. The transferred genes were further isolated and identified. One gene identified to be metallothionein-like protein type 3 gene was further transferred into Arabidopsis and reproduced a similar aberrant phenotype.

The GAINA system proves to be an efficient tool for batch identification of functional genes in Hevea brasiliensis, and also applicable in other non-model plants.