Grant Information

SCREENING AND CLONING OF RESISTANCE RELATED GENES BY RNA-SEQ IN HUANGLONGBING (HLB) RESISTANT AND SUSCEPTIBLE CITRUS BREEDING LINES

Sponsoring Institution Agricultural Research Service/USDA
Status ACTIVE
Funding Source USDA INHOUSE
Reporting Frequency Annual
Project Director DUAN Y
Accession Number 423348
Project Number 6034-22000-039-26R
Dates 2012-05-01 - 2015-04-30
Recipient Organization AGRICULTURAL RESEARCH SERVICE
219 SOUTH ROCK ROAD
FT PIERCE,FL 34945
Keywords bacteria
canker
citrus
ctv
epidemilogy
fungi
genomics
hlb
huanglongbing
molecular
pathogen
plum
pox
trsteza
virus
Research Effort Applied (30%)
Basic (60%)
Developmental (10%)
Classification Parameters
Knowledge AreaSubject of InvestigationField of SciencePercent
212 - Pathogens and Nematodes Affecting Plants 910 - Grapefruit 1040 - Molecular biology 25%
212 - Pathogens and Nematodes Affecting Plants 920 - Orange 1060 - Biology (whole systems) 25%
212 - Pathogens and Nematodes Affecting Plants 1114 - Peach 1040 - Molecular biology 10%
212 - Pathogens and Nematodes Affecting Plants 1122 - Strawberry 1060 - Biology (whole systems) 10%
212 - Pathogens and Nematodes Affecting Plants 1429 - Cucurbits, other (includes pumpkin, squash, gourd) 1040 - Molecular biology 10%
212 - Pathogens and Nematodes Affecting Plants 1460 - Tomato 1060 - Biology (whole systems) 10%
212 - Pathogens and Nematodes Affecting Plants 2110 - Ornamental trees and shrubs 1040 - Molecular biology 10%
Goals / Objectives
  1. Generate transcriptome profiles of both susceptible and resistant citrus responding to huanglongbing (HLB) infection.
  2. Identify key resistant genes from differentially expressed genes and gene clusters between the HLB-susceptible and HLB-resistant plants.
  3. Create transgenic citrus cultivars with new constructs containing the resistant gene(s).
Methods (unparsed)

Using RNA-Seq with next generation of sequencing technology, and intensive bioinformatics to identify key resistant genes from susceptible and resistant citrus plants in response to Candidatus Liberibacter asiaticus infections, and using routine transformation techniques to create transgenic citrus plant with the select resistant gene.

Methods
Using RNA-Seq with next generation of sequencing technology, and intensive bioinformatics to identify key resistant genes from susceptible and resistant citrus plants in response to Candidatus Liberibacter asiaticus infections, and using routine transformation techniques to create transgenic citrus plant with the select resistant gene.
Project Timeline Tracking

Outputs

This project is related to in-house project objective: 1. Characterize ecology, biology, epidemiology, molecular genetics, and vector and host (crop and weed) interactions of domestic, exotic, newly emerging, and re- emerging pathogens. First group of 5 samples for RNA-Seq (also called "Whole Transcriptome Shotgun Sequencing"), including resistant/tolerant vs. susceptible plants were nearly completed. Second group of 10 samples is in the sequencing process. We mapped the RNA-Seq data to reference genome, Citrus clementine using the computer program STAR. About 85% of the raw reads could be uniquely mapped. The transfrags of each library were assembled with cufflinks and merged with cuffmerg. 24275 genes of original predicted genes had been found with expressions. And a total of 10539 novel transfrags were identified with cufflinks, which were missing from the original reference genome annotation. Some of the Nucleotide Binding Site (NBS) genes were found to have an expression. For Citrus clementine and C. sinensis, there were 118,381 and 214,858 mRNAs or Expressed Sequence Tags (EST) s deposited in GenBank and 93 out of 607 and 221 out of 484 NBS related genes match one or more ESTs respectively. The number of EST varied from 1 to 25. We identified a few Leucine Rich Repeat Protein-Kinase (LRR-PK) genes for further comparative study based on the RNA-Seq data. The results indicated sequence variations of these genes in different varieties are indeed due to Single- Nucleotide Polymorphisms (SNP)/indels, and some of them were annotated as putative pseudogene because of a truncation. Further verifications is underway.