Deciphering Plant-Insect Interactions
‘The symposium brought stimulating discussions on the current state of the field, future prospects and how these could be applied within the African context for surveillance, diagnostics and management.
– Josiah Musembi Mutuku, BecA-ILRI Hub
On the first week of July,the BecA-ILRI Hub hosted a plant-insect interactions symposium to establish new partnership research on some of the greatest agricultural pest and disease challenges in Sub-Saharan Africa. The day saw talks from BecA-ILRI, the John Innes Centre, the International Institute for Tropical Agriculture, North Carolina State University, and Kenyatta University.
The morning started with an introduction from Jacob Mignouna on the new potential ACACIA offered for aligning strategy around research for development. This was swiftly followed by Sam Mugford of Saskia Hogenhout’s lab who spoke on his work on Hemiptera; sap-sucking insects. Through their work, they have been able to identify the genetic strategies used by insects through biochemical effectors to modify the behaviour of the plant. Recently also, the Hougenhout lab have developed rapid field collection techniques that allow for much faster analysis of insect interaction and pathogen spread. These two approaches offer great potential for partnering with southern hemisphere labs tackling insect based food security challenges.
“The JIC-BeCA joint symposium during our visit, this opened our eyes to the breadth and quality of research in plant-insect interactions across east Africa”
-Dr Sam Mugford, John Innes Centre
Beccy Corkill followed Sam with a run through of her incredible work on whitefly. While she is primarily based in the Hogenhout lab, Beccy is also part funded by Oxitec – a UK based biotechnology company working on new insect controls. In addition to being a major pest, whitefly function as the vector for numerous crop diseases and are suspected to be the cause of the recent spread of maize necrotic lethal disease. Beccy’s research and the work of Oxitec look into the potential for innovative genetic methods of insect control. This is particularly important as we try to move away from traditional pesticides to which many pests are becoming resistant and which are environmentally damaging in their application.
Whitefly study platforms have already been established at the BecA ILRI Hub thanks to the work of Gabby Chavez and Will Sharpee of North Carolina State University. Gabby spoke first on their research of Cassava Mosaic virus evolution which is transmitted by whitefly. Cassava mosaic virus is one of the major threats to Africa food security and can cause tremendous damage to cassava crops. Resistant varieties do exist but new strains of viruses are also being documented that pose potential risk to even the resistant varieties. Understanding how the virus can evolve within populations allows us to make more informed decisions around measures for creating resistance. Will followed Gabby’s talk with a demonstration of the impressive whitefly containment area they have put in place.
“The symposium was a fantastic day. I was able to share my science with fellow scientists and we made many connections”
-Beccy Corkill, John Innes Centre
Leena Tripathi spoke next around the incredible range of work she has been involved in within IITA. Since having successfully established at transformation platform for banana, Leena has been developing resistant varieties of plantain and banana to a range of highly damaging diseases such as banana Xanthomonas wilt disease. Across some parts of Africa, an individual can eat over a kilogram of banana and plantain a day and so unless controlled, diseases such as Xanthomonas wilt disease present great threats to local food security. Leena was also interested in looking into the potential for developing banana aphid resistant lines using similar understandings of the interactions Sam and Beccy study.
Finally Steven Runo of Kenyatta University spoke on his research into the parasitic plant striga that causes significant damage across monocotyledons and dicotyledons cultivars. The striga plant hijacks the host plant’s potential pathways for mycorrhzal symbiosis, growing into the root of the host plant and accessing the nutrients within. In order to do this, the striga plant manipulates the host system and Steve’s work is looking further into these methods the parasite utilises. Steve also shared an interest the emerging threat of Maize necrotic lethal disease, another insect vectored viral disease that has recently be spreading across Sub-Saharan Africa.
‘My interaction with insect scientists from the JIC made me appreciate the commonness of effectors in insect-host and parasitic plants-host interactions’
– Professor Steven Runo, Kenyatta University
The afternoon then began with a full tour of the lab facilities that the BecA-ILRI Hub offers conducted by Julius Osaso and Josiah Mutuku. During this tour, we were able to see the new KASP genotyping platform being set up by Oluwasyi Shorinola and Ben Kiawa. The new platform allows higher quality and more cost effective SNP genotyping throughput compared to other SSR and gel-based genotyping platforms. Finally after this, Will and Gabby provided a tour of the whitefly platform they have established within the BecA facilities.
The following days after the symposium included a visit Steve’s lab at Kenyatta university. Upon entering the lab, we were delighted to see that two of Steve’s students were familiar faces, Joel Masanga and Godfrey Ngure, who had taken part in the previous BecA-JIC Alliance capacity building exercises; ASSET and Golden Gate training. Steve demonstrated the incredible system he had set up for high throughput hydroponics of striga.
Finally the symposium ended with a visit to the field to understand the immediate challenges faced by smallholder farmers on the ground. It’s always astonishing when coming from more intensive single crop agriculture to see the incredible diversity within African smallholder plots. In the space of perhaps around two acres, the small plot contained at least over ten different crops along with livestock and beehives. On closer inspection however, the same issues of insect damage could still be clearly seen across the site. In a times of rising pest resilience to already expensive insecticides, it is vital we understand these interactions if we are to meet the growing challenges of food security.
Special thanks are due especially to Dr Josiah Mutuku for all his help and the BecA-ILRI Hub for hosting the event.