GWAS Provides Biological Insights into Mechanisms of the Parasitic Plant (Striga) Resistance in Sorghum
Background: Sorghum yields in sub-Saharan Africa (SSA) are greatly reduced by parasitic plants of the genus Striga (witchweed). Vast global sorghum genetic diversity collections, as well as the availability of modern sequencing technologies, can be potentially harnessed to effectively manage the parasite.
Results: We used laboratory assays – rhizotrons to screen a global sorghum diversity panel to identify new sources of resistance to Striga; determine mechanisms of resistance, and elucidate genetic loci underlying the resistance using genome-wide association studies (GWAS). New Striga resistant sorghum determined by the number, size and biomass of parasite attahements were identified. In total 13 sorghum genotypes had higher or comparable resistance levels as IS9830 and N13 used as resistance checks. Resistance was by; i) mechanical barriers that blocked parasite entry, ii) elicitation of a hypersensitive reaction that interfered with parasite development, and iii) the inability of the parasite to develop vascular connections with hosts. Resistance genes underpinning the resistance corresponded with the resistance mechanisms and included pleiotropic drug resistance proteins that transport resistance molecules; xylanase inhibitors involved in cell wall fortification and hormonal regulators of resistance response, Ethylene Response Factors.
Conclusions: Our findings are of fundamental importance to developing durable and broad-spectrum resistance against Striga and have far-reaching applications in many SSA countries where Striga threatens the livelihoods of millions of smallholder farmers that rely on sorghum as a food staple.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
This is a list of supplementary files associated with this preprint. Click to download.
Posted 17 Sep, 2020
Received 12 Oct, 2020
On 12 Oct, 2020
Received 09 Oct, 2020
On 01 Oct, 2020
On 30 Sep, 2020
On 29 Sep, 2020
Invitations sent on 16 Sep, 2020
On 31 Aug, 2020
On 30 Aug, 2020
On 30 Aug, 2020
Posted 05 Aug, 2020
GWAS Provides Biological Insights into Mechanisms of the Parasitic Plant (Striga) Resistance in Sorghum
Posted 17 Sep, 2020
Received 12 Oct, 2020
On 12 Oct, 2020
Received 09 Oct, 2020
On 01 Oct, 2020
On 30 Sep, 2020
On 29 Sep, 2020
Invitations sent on 16 Sep, 2020
On 31 Aug, 2020
On 30 Aug, 2020
On 30 Aug, 2020
Posted 05 Aug, 2020
Background: Sorghum yields in sub-Saharan Africa (SSA) are greatly reduced by parasitic plants of the genus Striga (witchweed). Vast global sorghum genetic diversity collections, as well as the availability of modern sequencing technologies, can be potentially harnessed to effectively manage the parasite.
Results: We used laboratory assays – rhizotrons to screen a global sorghum diversity panel to identify new sources of resistance to Striga; determine mechanisms of resistance, and elucidate genetic loci underlying the resistance using genome-wide association studies (GWAS). New Striga resistant sorghum determined by the number, size and biomass of parasite attahements were identified. In total 13 sorghum genotypes had higher or comparable resistance levels as IS9830 and N13 used as resistance checks. Resistance was by; i) mechanical barriers that blocked parasite entry, ii) elicitation of a hypersensitive reaction that interfered with parasite development, and iii) the inability of the parasite to develop vascular connections with hosts. Resistance genes underpinning the resistance corresponded with the resistance mechanisms and included pleiotropic drug resistance proteins that transport resistance molecules; xylanase inhibitors involved in cell wall fortification and hormonal regulators of resistance response, Ethylene Response Factors.
Conclusions: Our findings are of fundamental importance to developing durable and broad-spectrum resistance against Striga and have far-reaching applications in many SSA countries where Striga threatens the livelihoods of millions of smallholder farmers that rely on sorghum as a food staple.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5