Detlef Weigels research group at the Max Planck Institute in Tbingen had initially pioneered this technique in the model plant Arabidopsis thaliana. The plethora of potential applications in agriculture now motivated them to try the method in rice. One of the rice genes they targeted is called Eui1. When Eui1 is inactive, the uppermost part of the rice plant and parts of the flowers grow taller and the plants can more easily fertilize neighboring plants; breeders use this genetic trick for hybrid seed production. Originally identified as a spontaneous mutant in a japonica rice variety, the eui1 mutation was introduced into indica varieties by several years of breeding. With an artificial miRNA targeting the Eui1 messenger RNA, the researchers at the International Rice Research Institute obtained within weeks plants with the desired property in two different rice varieties, including the agronomically important indica variety IR64, the most commonly grown strain in South-East Asia. Similarly, the researchers also report successful silencing of two other genes, Pds and SPl11.
Besides allowing the quick transfer of reduced gene function between different varieties, artificial miRNAs also accelerate the initial identification of important genes and the discovery of functions of genes that have not been studied before. Potential applications in rice breeding are manifold and they dont stop at rice genes. By targeting pathogen-derived genes, for example, it should be possible to enhance virus and insect resistance. In addition, because they act dominantly, they are also perfectly suited for hybrid breeding.
MiRNAs have been found in all plant species examined so far. It should hen
|Contact: Norman Warthmann|
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