Chinese scientists have identified two critical genes responsible for sorghum's resistance to Striga, a parasitic plant that causes significant crop losses.
The study, published in the journal Cell, was conducted by
researchers from the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences, China Agricultural University and other institutions.
Striga, also known as "witchweed," is a destructive parasitic plant that depends on host plants for nutrients and water, severely affecting crop yields and agricultural ecosystems.
Sorghum, a vital crop in many regions, is vulnerable to Striga infestation. Sorghum roots release strigolactones (SLs), a class of plant hormones that help recruit mycorrhizal fungi for nutrient uptake. However, these same SLs inadvertently act as signals for dormant Striga seeds in the soil, triggering their germination and subsequent infestation of the host plant, explained Xie Qi, a researcher from IGDB.
"The parasitization process of the Striga is extremely insidious and difficult to control," Xie said.
Using gene mining techniques alongside big data analysis and other technologies, the research team has identified two key genes, SbSLT1 and SbSLT2, for the first time. Their findings reveal that knocking out these genes inhibits SL secretion. Under these conditions, Striga is unable to germinate and infect the host.
Field trials demonstrated that sorghum with knocked-out SbSLT1 and SbSLT2 genes exhibited 67 to 94 percent lower infestation rates and 49 to 52 percent reduction in yield loss, according to the study.
These findings offer valuable genetic resources and technical support for breeding Striga-resistant sorghum varieties, Xie said.
The researchers emphasized that the discovery of SbSLT1 and SbSLT2 could provide crucial tools for combating parasitic plants, potentially addressing food security challenges in countries severely affected by parasitic plants, especially African and Asian countries. Future research will focus on validating these genes in crops such as maize, tomato and millet.
