Method for treatment and control of plant disease

Patent metadata

Field	Value
Publication number	US-10212941-B2
Application number	US-201615174564-A
Country	US
Kind code	B2
Filing date	Jun 6, 2016
Priority date	Oct 19, 2012
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

The present invention provides methods for development of a virulent bacteriophage-based treatment for the control of plant diseases caused by Xylella fastidiosa . The invention further provides methods of isolating and propagating bacteriophage virulent to X. fastidiosa in a Xanthomonas bacterial host and for treating or reducing symptoms of X. fastidiosa infection in a plant. The invention further provides methods of isolating and propagating bacteriophage virulent to Xanthomonas axonopodis pv. citri and for treating or reducing symptoms of Xanthomonas axonopodis pv. citri infection in a plant.

First claim

What is claimed is:

1. A method of preventing or reducing symptoms or disease associated with Xanthomonas axonopodis pv. citri or Xylella fastidiosa in a plant, comprising contacting said plant with a population of virulent bacteriophage particles that includes Xylella fastidiosa in its host range, wherein the virulent bacteriophage is selected from the group consisting of: the Xfas100 phage type and the Xfas300 phage type;
wherein the Xfas100 type phage has the following characteristics:
(a) the bacteriophage is capable of lysing said Xylella fastidiosa and/or Xanthomonas bacteria;
(b) the bacteriophage infects a cell by binding to a Type IV pilus;
(c) the phage belongs to Siphoviridae family and has capsid size ranging from 55-77 nm in diameter;
(d) the genomic size of bacteriophage is about 55500 bp to 56200 bp; and
(e) the bacteriophage prevents or reduces symptoms associated with X. fastidiosa or Xanthomonas axonopodis pv. citri and subspecies thereof, in a plant or plants;

and wherein the Xfas300 type phage has the following characteristics:
(f) the bacteriophage is capable of lysing said Xylella fastidiosa and/or Xanthomonas bacteria;
(g) the bacteriophage infects a cell by binding to a Type IV pilus;
(h) the phage belongs to Podoviridae family and has capsid size ranging from 58-68 nm in diameter;
(i) the genomic size of bacteriophage is about 43300 bp to 44600 bp; and
(j) the bacteriophage prevents or reduces symptoms associated with X. fastidiosa or Xanthomonas axonopodis pv. citri and subspecies thereof, in a plant or plants.

2. The method of claim 1 , wherein contacting comprises introducing the bacteriophage particles into the plant.

3. The method of claim 1 , wherein the plant is selected from the group consisting of a Citrus spp., a Fortunella spp., a Poncirus spp., a lime, a lemon, an orange, a grapefruit, a pomelo, a grapevine plant, almond, coffee, alfalfa, oleander , oak, sweetgum, redbud, elm, peach, apricot, plum, blackberry, mulberry, Chitalpa tashkentensis , and hybrids of trifoliate orange used for rootstocks.

4. The method of claim 1 , wherein the bacteriophage particles are introduced into the plant by injection, by an insect vector, via the root system, by injection, by spray, by mist, or by dust on the plant.

5. The method of claim 4 , wherein the insect vector is a glassy winged sharpshooter.

6. The method of claim 1 , wherein the number of said bacteriophage to be introduced into said plant is from 1 to 10 12 PFU/ml.

7. The method of claim 1 , wherein the number of said bacteriophage to be introduced into said plant is from 10 4 to 10 11 PFU/ml.

8. The method of claim 1 , wherein the number of said bacteriophage to be introduced into said plant is from 10 7 to 10 10 PFU/ml.

9. The method of claim 1 , defined as comprising contacting a population of plants with the bacteriophage particles to prevent or reduce symptoms associated with Xanthomonas axonopodis and pathovars thereof in the population.

10. The method of claim 1 , wherein said virulent bacteriophage comprises at least one bacteriophage selected from the group consisting of: the Xfas100 phage type and the Xfas300 phage type, wherein the Xfas100 phage type is at least one bacteriophage selected from Xfas103, Xfas106; and the Xfas300 phage type is at least one bacteriophage selected from Xfas302, Xfas303, Xfas304, and Xfas306; wherein samples of said bacteriophage have been deposited under ATCC Accession Numbers PTA-13096, PTA-13095, PTA-13098, PTA-13099, PTA-13100, and PTA-13097, respectively, for phage Xfas103, Xfas106, Xfas302, Xfas303, Xfas304, and Xfas306.

11. The method of claim 1 , wherein said bacteriophage virulent to Xylella fastidiosa are introduced simultaneously or sequentially to the plant by a combination of two, three, four, five, or six virulent bacteriophage strains.

12. The method of claim 1 , defined as comprising contacting a population of plants with the bacteriophage particles to prevent or reduce symptoms associated with X. fastidiosa or Xanthomonas axonopodis pv. citri and subspecies thereof, in the population.

13. The method according to claim 1 , wherein the bacteriophage is propagated in a culture of Xanthomonas bacteria.

Assignees

• Texas A & M Univ Sys

Inventors

• Gonzalez Carlos F
• Ahern Stephen J
• Das Mayukh
• Young Iii Ryland F
• Bhowmick Tushar Suvra

Classifications

• C12N2795/10231

  Uses of virus other than therapeutic or vaccine, e.g. disinfectant · CPC title

• C12N2795/10251

  Methods of production or purification of viral material · CPC title

• C12N2795/10321

  Viruses as such, e.g. new isolates, mutants or their genomic sequences · CPC title

• C12N2795/10233

  Use of viral protein as therapeutic agent other than vaccine, e.g. apoptosis inducing or anti-inflammatory · CPC title

• C12N7/00

  Viruses; Bacteriophages; Compositions thereof; Preparation or purification thereof (preparing medicinal viral antigen or antibody compositions, e.g. virus vaccines, A61K39/00) · CPC title