Project Number: 3096-21000-022-06-N
Project Type: Non-Funded Cooperative Agreement
Start Date: Jun 30, 2018
End Date: Sep 30, 2020
1. Investigate the molecular mechanism underlying FOV pathogenicity - colonization process in Upland and Pima susceptible and resistant/tolerant cotton lines. 2. Identify FOV resistance genes through candidate gene approach.
The purpose of this project is to strengthen cooperation among the parties to decipher and understand the complex disease resistance mechanisms of Fusarium oxysporum f. sp. vasinfectum (FOV) for cotton improvement in the post-genome era. Research at Texas A&M AgriLife, molecular plant-microbe interaction laboratory involves the elucidation of novel plant immune signaling pathways and mainly focuses on the mechanisms of plant disease resistance. The laboratory has established a series of platforms, including high throughput viral vector-based transient loss-of-function and gain-of-function assays, stable transformation and various molecular and biochemical assays in cotton. Research by the USDA-ARS and Texas A&M AgriLife cooperators involves disease resistance evaluations for FOV and root knot nematode (RKN) of germplasm and mapping populations. Breeding material or cotton entries have been selected/developed with resistant to FOV race 4 (FOV4). These and additional entries of interest identified from ongoing screening and selection efforts at the USDA-ARS, CSRL, Plant Stress and Germplasm Development Research, Lubbock, TX and/or other germplasm sources will be used as appropriate for this project. In addition, several recombined inbred lines (RILs) mapping populations have be genotyped using the CottonSNP63K Illumina Infinium array, and using the next generation sequencing technology, information from expressed genes have been generated from infected and uninfected roots of susceptible and resistant/tolerant entries, including PS6 and PS7. To understand the molecular mechanism underlying FOV pathogenicity, Texas A&M AgriLife laboratory aims to monitor the fungal attachment, penetration, colonization and establishment in the cotton vascular bundles by live-cell imaging through the course of infection period using green fluorescent protein (GFP)-tagged FOV strains on susceptible and resistant entries. And to determine the importance of candidate immune receptor genes (plant resistance genes) in FOV resistance, the laboratory has performed large-scale virus-induced gene silencing (VIGS) assays. To identify FOV resistance genes through candidate gene approach. Recent development in targeted sequencing has facilitated the identification of resistance genes in wheat and potato. By developing targeted probes to examine the genetic diversity of immune receptor genes in diverse cotton species/cultivars, by capture sequencing, and monitoring their spatio-temporal expression pattern in response to fungal wilt pathogens by massive parallel targeted RNA-Seq, information of candidate genes will be generated, and then this information can be used to develop markers and identify resistance genes associated with FOV diseases. In addition, from the ongoing genetic and QTL mapping research approach at the USDA-ARS, candidate genes will be identified, and then used to clone FOV genes. Identified genes with SNP-biomarkers will eventually be used in marker-assisted breeding for developing stress-tolerant (biotic) cotton genotypes. These efforts advance the capacity to reveal the complex disease resistance mechanisms for cotton improvement in the post-genome era.