Sponsoring Institution
Agricultural Research Service/USDA
Status
ACTIVE
Funding Source
USDA INHOUSE
Reporting Frequency
Annual
Project Director
ROSSKOPF E N
Accession Number
440129
Project Number
6034-21000-019-006R
Dates
2020-10-01 - 2022-01-15
Recipient Organization
AGRICULTURAL RESEARCH SERVICE
219 SOUTH ROCK ROAD
FT PIERCE,FL 34945
Keywords
ammendments
citrus
cultural
disease
huanglongbing
microbiome
pathology
phyisiology
practices
rootstocks
soil
Research Effort
Applied (30%)
Basic (70%)
Developmental (0%)
Classification Parameters
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|
| 203 - Plant Biological Efficiency and Abiotic Stresses Affecting Plants |
920 - Orange |
1000 - Biochemistry and biophysics |
50% |
| 204 - Plant Product Quality and Utility (Preharvest) |
999 - Citrus, general/other |
1080 - Genetics (excludes breeding) |
50% |
Goals / Objectives
The research objective of this proposal is to investigate the root collapse associated with Huanglongbing (HLB)-impacted trees and methods to mitigate it by promoting root health. Our previous work demonstrates that as HLB severity increases, the root microbiome becomes enriched in soil-borne pathogens.
Methods (unparsed)
We will conduct experiments to empirically determine if these pathogens exacerbate the Huanglongbing (HLB)-associated root (and canopy) decline. We will integrate field studies that test HLB resistant/tolerant rootstocks and use of soil amendments that promote root health to determine if they suppress pathogenic shifts in the microbiome and prolong tree longevity/productivity under HLB pressure. These field studies will include newly established and mature groves. To support our field trials and decipher the genes/gene pathways that dictate resistance or susceptibility to HLB, we will determine how rootstocks and scions respond to Candidatus Liberibacter asiaticus using a large collection of citrus genotypes that cover a spectrum of highly HLB-susceptible to HLB-resistant using a combination of global transcriptomics and expression quantitative loci mapping underpinned by a Citrus/Poncirus pan-genome analysis. We will use this data as a source of HLB resistance genes to functionally test sectors of the citrus immune system and to create HLB-resistant rootstocks and scions using CRISPR/Cas9 gene-editing with a new plant transformation strategy that increases the efficiency of citrus regeneration. We will integrate this research with a robust extension and outreach program in combination with an economic cost-benefit analysis structured around adoption of treatments that enhance root health in commercial citriculture.
Methods
We will conduct experiments to empirically determine if these pathogens exacerbate the Huanglongbing (HLB)-associated root (and canopy) decline. We will integrate field studies that test HLB resistant/tolerant rootstocks and use of soil amendments that promote root health to determine if they suppress pathogenic shifts in the microbiome and prolong tree longevity/productivity under HLB pressure. These field studies will include newly established and mature groves. To support our field trials and decipher the genes/gene pathways that dictate resistance or susceptibility to HLB, we will determine how rootstocks and scions respond to Candidatus Liberibacter asiaticus using a large collection of citrus genotypes that cover a spectrum of highly HLB-susceptible to HLB-resistant using a combination of global transcriptomics and expression quantitative loci mapping underpinned by a Citrus/Poncirus pan-genome analysis. We will use this data as a source of HLB resistance genes to functionally test sectors of the citrus immune system and to create HLB-resistant rootstocks and scions using CRISPR/Cas9 gene-editing with a new plant transformation strategy that increases the efficiency of citrus regeneration. We will integrate this research with a robust extension and outreach program in combination with an economic cost-benefit analysis structured around adoption of treatments that enhance root health in commercial citriculture.