Target-Site Mutations and Expression of <i>ALS</i> Gene Copies Vary According to <i>Echinochloa</i> Species
The sustainability of rice cropping systems is jeopardized by the large number and variety of populations of polyploid <i>Echinochloa</i> spp. resistant to ALS inhibitors. Better knowledge of the <i>Echinochloa</i> species present in Italian rice fields and the study of <i...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | article |
| Language: | EN |
| Published: |
MDPI AG
2021
|
| Subjects: | |
| Online Access: | https://doaj.org/article/3f384c4df5a647edb924b50b2581e8d9 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The sustainability of rice cropping systems is jeopardized by the large number and variety of populations of polyploid <i>Echinochloa</i> spp. resistant to ALS inhibitors. Better knowledge of the <i>Echinochloa</i> species present in Italian rice fields and the study of <i>ALS</i> genes involved in target-site resistance could significantly contribute to a better understanding of resistance evolution and management. Using a CAPS-<i>rbcL</i> molecular marker, two species, <i>E. crus-galli</i> (L.) P. Beauv. and <i>E. oryzicola</i> (Vasinger) Vasing., were identified as the most common species in rice in Italy. Mutations involved in ALS inhibitor resistance in the different species were identified and associated with the <i>ALS</i> homoeologs. The relative expression of the <i>ALS</i> gene copies was evaluated. Molecular characterization led to the identification of three <i>ALS</i> genes in <i>E. crus-galli</i> and two in <i>E. oryzicola</i>. The two species also carried different point mutations conferring resistance: Ala122Asn in <i>E. crus-galli</i> and Trp574Leu in <i>E. oryzicola</i>. Mutations were carried in the same gene copy (<i>ALS1</i>), which was significantly more expressed than the other copies (<i>ALS2</i> and <i>ALS3</i>) in both species. These results explain the high resistance level of these populations and why mutations in the other <i>ALS</i> copies are not involved in herbicide resistance. |
|---|