Candidate genes from Gwas and Rnaseq for Beech Bark Disease resistance in American Beech
|Authors:||John E. Carlson, Irina Ćalić, Jennifer Koch, David Carey, Charles Addo-Quaye, Donghwan Shim, David B. Neale|
|Type:||Proceedings - Paper|
|Station:||Southern Research Station|
|Source:||In: Publication: Gen. Tech. Rep. SRS-252. Asheville, NC: U.S. Department of Agriculture Forest Service. Southern Research Station|
AbstractAmerican beech (Fagus grandifolia Ehrh.) is an aesthetically, ecologically, and economically important native component of the North American eastern hardwood forest. American beech is susceptible to beech bark disease (BBD), however, and has suffered high rates of mortality as the disease complex spreads. The invasive sap-feeding woolly beech scale insect (Cryptococcus fagisuga) is the pre-disposing factor for infection by introducing either Neonectria faginata or N. ditissima fungus species that result in extensive cankering of American Beech trees. A small percentage of trees survive BBD attack, and many of these show signs of natural resistance to the insect vector in the egg-inoculation tests used to assay for resistance. We have developed and applied genomics resources to learn more about the molecular genetic basis of gene expression and gene sequence variation associated with cases of natural resistance to the insect. Initially, transcriptome resources were developed, and differential gene expression analyses conducted from which candidate genes were selected. From the transcriptome, an SNP chip assay was developed to genotype an association population of 506 individuals from across the American beech range, 249 of which were resistant and 257 susceptible to BBD. We also constructed a genetic linkage map based on SNPs with a full-sib family of 115 individuals to locate BBD-resistance QTL. The GWAS project revealed four highly significant SNPs on Linkage Group 5 for a single gene encoding a metallothioneinlike protein. Metallothioneins are cysteine-rich metal chelator proteins that can moderate oxidative stress by coordinating metal atoms, which may provide a resistance mechanism against the woolly beech scale insect.
- Proceedings of the Sixth International Workshop on the Genetics of Host-Parasite Interactions in Forestry—Tree Resistance to Insects and Diseases: Putting Promise into Practice