Towards Engineering Resistance against FOC
About us
A joint initiative from the scientist of Warwick University, UK and Tamil Nadu Agricultural University (TNUA), India towards engineering resistance against Fusarium oxysporum f. sp. cubense (Foc). The project Engineering Resistance against FOC (EnRes-FOC), funded by the Royal Society, aims to unravel the genomic complexity of both banana and Fusarium oxysporum f. sp. cubense to engineer resistance against this potentially devastating pathogen. This will pave way towards genetic enhancement of bananas for disease resistance and several other production constraints.
What we do
We have sequenced banana genotypes that are susceptible or exhibit race-specific resistance. Polymorphisms and differentially expressed genes associated with pathogenicity in Foc have been identified. In parallel, RNAseq (and specifically Ren-seq) will be carried out on virulent and avirulent interactions to identify Foc infection strategies (pathogen and host transcriptomes will be captured). These data will (i) illustrate pathogen virulence strategies and host defence response pathways, (ii) enhance genome assemblies.
Further, at Warwick, we have been generating assemblies for Foc isolates collected and sequenced by TNAU.
A potential "Bananageddon!"
Bananas (Musa spp.) are one of the world’s top agricultural commodities. Global banana production reached 114 million tonnes in 2017 after recording an annual production increase of 3.2% from 2000 (FAO, 2018). Yet, only around 15% of bananas produced are traded in international markets, the remaining 85% is consumed locally (FAO, 2018). Bananas are a staple food crop in many producing regions and can account for up to 25% of daily calorie intake. Moreover, bananas are often cultivated as a cash crop providing an important source of income in developing countries.
As a consequence of its clonal nature, banana production suffers significantly from pathogens. In the last banana apocalypse, the soil-borne vascular pathogen Fusarium oxysporum f. sp. cubense Race 1 (R1) devastated global production of “Gros Michel”. Approximately 40,000 hectares of ‘Gros Michel’ plantations were destroyed by Foc R1, which resulted in estimated economic losses of $400 million (USD) between 1940 and 1960.
The Cavendish banana subgroup was identified as resistant to Foc R1, and having a skin thick enough to facilitate global transportation, subsequently replaced ‘Gros Michel’. However, in the 1980s Cavendish banana plants in Taiwan were observed displaying symptoms of Foc infection. Identified in 1994 as Foc Race 4 (R4), this strain affecting Cavendish bananas has continued to spread; Foc R4 is now found in Africa and Asia (Ploetz, 2015a), was identified in India in 2017, and has recently been reported in Columbia (June 2019).
India, the biggest producer of bananas in the world (~30% global production), consumes nearly all its production. The recent arrival of highly virulent Foc Tropical Race 4 (TR4) (syn. Fusarium odoratissimum) in India has potentially catastrophic consequences, threatening food security, and with it India’s economy and social structure. Given the challenges of banana breeding (polyploidy, sterility), it may be feasible to use synthetic biology approaches to engineer TR4 resistance.
To do this we need to first unravel the genomic complexity of banana and F. oxysporum f. sp cubense to engineer resistance against TR4. This project seeks to screen the unique genetic diversity found in Indian banana cultivars for differential responses against Race 1 (still a major problem in India) and TR4 isolates using the extensive banana germplasm available at Tamil Nadu Agricultural University (TNAU). India grows about 20 commercial varieties of banana of which 10 are represented in Tamil Nadu state.
