Maize is an important crop, feeding millions of people especially in Africa. One of the main problems influencing maize harvest yields is the parasitic witchweed Striga.
MiCRop researchers Harro Bouwmeester, Lemeng Dong, Chengsheng Li, Marnix Medema and a team of international collaborators have identifed a maize line that is resistant to Striga. They also were able to identify two strigolactones that stimulate less Striga germination than the major maize strigolactones. Last but not least, they identified two parallel strigolactone pathways in maize, thereby opening a perspective for breeding Striga resistance in other maize lines. This could help to reduce the devastating effects of Striga on maize harvest and increase yields.

The photo shows Striga infecting maize in the field (photo with thanks to Muhammad Jamil).

The study was published in Science today. You can also find a new article about this publication on the UvA website (in Dutch and English).


Abstract:
Maize (Zea mays) is a major staple crop in Africa, where its yield and the livelihood of millions are compromised by the parasitic witchweed Striga. Germination of Striga is induced by strigolactones exuded from maize roots into the rhizosphere. In a maize germplasm collection, we identified two strigolactones, zealactol and zealactonoic acid, which stimulate less Striga germination than the major maize strigolactone, zealactone. We then showed that a single cytochrome P450, ZmCYP706C37, catalyzes a series of oxidative steps in the maize-strigolactone biosynthetic pathway. Reduction in activity of this enzyme and two others involved in the pathway, ZmMAX1b and ZmCLAMT1, can change strigolactone composition and reduce Striga germination and infection. These results offer prospects for breeding Striga-resistant maize.

C. Li, L. Dong, J. Durairaj, J.-C. Guan, M. Yoshimura, P. Quinodoz, R. Horber, K. Gaus, J. Li, Y. Setotaw, J. Qi, H. De Groote, Y. Wang, B. Thiombiano, K. Floková, A. Walmsley, T. Charnikhova, A. Chojnacka, S. Correia de Lemos, Y. Ding, D. Skibbe, K. Hermann, C. Screpanti, A. De Mesmaeker, E. Schmelz, A. Menkir, M. Medema, A. Van Dijk, J.Wu, K. Koch, H. Bouwmeester: ‘Maize resistance to witchweed through changes in strigolactone biosynthesis’, in Science (6 January 2023). DOI: 10.1126/science.abq4775