This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: The rice disease bacterial leaf blight (for short: BB) is causing significant yield losses in Asia and Africa. It is triggered by the bacterium Xanthomonas oryzae pv. oryzae (Xoo), which has many distinct regional strains on various continents.
Recently, researchers employed the "marker-assisted breeding" (MAB) technique to develop variants of African elite rice lines that are resistant to a detrimental crop disease. Asian Xoo strains were unintentionally introduced into East Africa around 2019 and had a major impact in Madagascar and Tanzania, among other countries. Although the local African rice varieties are adapted to many of the African bacterial strains, they have no resistance to these newly arrived Asian strains.
The infection subsequently spread from Tanzania into neighboring countries. A team from the French National Research Institute for Sustainable Development (IRD) headed by Dr. Boris Szurek was able to trace the genetic origins of the Xoo variants back to Asia and map their spread into Africa in detail.
The team from the "Healthy Crops" international research project headed by Dr. Frommer from the Institute for Molecular Physiology at Heinrich Heine University Düsseldorf (HHU) specializes in developing solutions to fight Xoo and BB. The researchers have found a way to cut the bacterium off from its food supply: Xoo activates specific sugar transporters, the so-called SWEET genes, in the rice plant to obtain sugar on which to feed.
The researchers used genome editing to adjust the corresponding sites in the rice's genetic material to prevent the bacterium from switching on these genes, thereby making the plant resistant. This approach is quick and precise. However, approval procedures for genome-edited plants must be in place in the country concerned.
As this is not the case in numerous East African countries, the team deliberately chose a different approach in the study that has now been published. Using endemic African rice varieties, the researchers developed new lines resistant to the Xoo strains spreading across East Africa without employing genome editing. Frommer said, "To enable our lines to still reach farmers quickly, we transferred resistance genes into three elite rice varieties widely used in Africa by means of the so-called marker-assisted breeding technique." The MAB technique adds the resistance genes while retaining the general properties of the original varieties.
Extract — continue reading at the source.
