The effect of two QTLs for resistance to in cotton on nematode egression from roots.

Cotton is widely grown in the southern US and is its most significant pathogen. The germplasm line M-120 RNR is highly resistant to due to two resistance QTLs (quantitative trait loci), and . Both QTLs reduce total egg production, but the QTLs affect development at different life stages.

Small RNA and degradome deep sequencing reveals important roles of microRNAs in cotton (Gossypium hirsutum L.) response to root-knot nematode Meloidogyne incognita infection.

Investigation of cotton response to nematode infection will allow us to better understand the cotton immune defense mechanism and design a better biotechnological approach for efficiently managing pest nematodes in cotton. In this study, we firstly treated cotton by root knot nematode (RKN, Meloidogyne incognita) infections, then we employed the high throughput deep sequencing technology to sequence and genome-widely identify all miRNAs in cotton; finally, we analyzed the functions of these miRNAs in cotton response to RKN infections. A total of 266 miRNAs, including 193 known and 73 novel miRNAs, were identified by deep sequencing technology, which belong to 67 conserved and 66 novel miRNA families, respectively.

Sequence Composition of Bacterial Chromosome Clones in a Transgressive Root-Knot Nematode Resistance Chromosome Region in Tetraploid Cotton.

Plants evolve innate immunity including resistance genes to defend against pest and pathogen attack. Our previous studies in cotton ( spp.) revealed that one telomeric segment on chromosome (Chr) 11 in cv.

Characterization of Current f. sp. Isolates from Cotton in the San Joaquin Valley of California and Lower Valley El Paso, Texas.

f. sp. race 4 is a causal agent of Fusarium wilt of cotton ( spp.

Functional PPO2 mutations: co-occurrence in one plant or the same ppo2 allele of herbicide-resistant Amaranthus palmeri in the US mid-south.

Background: Protoporphyrinogen IX oxidase 2 (PPO2) inhibitors are important for the management of glyphosate- and acetolactate synthase-resistant Palmer amaranth [Amaranthus palmeri (S.) Wats.].

Characterization of the Complete Genome and P0 Protein for a Previously Unreported Genotype of Cotton Leafroll Dwarf Virus, an Introduced Polerovirus in the United States.

Virus-like disease symptoms consisting of leaf cupping, shortened internodes, and overall stunting were observed in commercial cotton fields in Alabama in 2017 to 2018. To determine the complete genome sequence of the suspected causal polerovirus, symptomatic leaf samples were collected in Macon County, Alabama, and subjected to Illumina RNA sequencing. Based on BLASTn analysis, the Illumina contig of 5,771 nt shared the highest nucleotide identity (approximately 95%) with members of the species (CLRDV) (genus ; family ) from Argentina and Brazil.

Small RNA Sequencing Reveals Regulatory Roles of MicroRNAs in the Development of .

MicroRNAs (miRNAs) are an extensive class of small regulatory RNAs. Knowing the specific expression and functions of miRNAs during root-knot nematode (RKN) () development could provide fundamental information about RKN development as well as a means to design new strategies to control RKN infection, a major problem of many important crops. Employing high throughput deep sequencing, we identified a total of 45 conserved and novel miRNAs from two developmental stages of RKN, eggs and J2 juveniles, during their infection of cotton ().

Transcriptome analysis of a nematode resistant and susceptible upland cotton line at two critical stages of Meloidogyne incognita infection and development.

Host plant resistance is the most practical approach to control the Southern root-knot nematode (Meloidogyne incognita; RKN), which has emerged as one of the most serious economic pests of Upland cotton (Gossypium hirsutum L.). Previous QTL analyses have identified a resistance locus on chromosome 11 (qMi-C11) affecting galling and another locus on chromosome-14 (qMi-C14) affecting egg production.

Detection and Characterization of f. sp. VCG0114 (Race 4) Isolates of Diverse Geographic Origins.

A highly virulent cotton wilt pathogen, f. sp. VCG0114 (race 4) was found in West Texas in 2017, after being known in California since 2001.

Fusarium wilt of cotton may commonly result from the interaction of f. sp. with .

The interaction between f. sp. (Fov) and (root-knot nematode) resulting in Fusarium wilt (FW) of cotton is well-known.

Resistance Quantitative Trait Loci and in Cotton Have Different Effects on the Development of , the Southern Root-Knot Nematode.

Quantitative trait loci (QTLs) and impart a high level of resistance to in cotton. Breeders had previously backcrossed both QTLs into the susceptible Coker 201 to create the highly resistant M-120 RNR, and we crossed Coker 201 and M-120 RNR to create near-isogenic lines with either or . Previous work suggests different modes of action for and .

Development of a qPCR Protocol to Detect the Cotton Bacterial Blight Pathogen, Xanthomonas citri pv. malvacearum, from Cotton Leaves and Seeds.

Bacterial blight, historically a seed-borne disease of cotton (Gossypium hirsutum) is caused by Xanthomonas citri pv. malvacearum, resulted in significant economic losses prior to development of resistant varieties and implementation of acid-delinting of planting seed. Periodic outbreaks have been associated with seed since the early twentieth century; of note, the disease has experienced a resurgence since 2011.

RNA-Seq transcriptome analysis of Amaranthus palmeri with differential tolerance to glufosinate herbicide.

Amaranthus palmeri (Amaranthaceae) is a noxious weed in several agroecosystems and in some cases seriously threatens the sustainability of crop production in North America. Glyphosate-resistant Amaranthus species are widespread, prompting the use of alternatives to glyphosate such as glufosinate, in conjunction with glufosinate-resistant crop cultivars, to help control glyphosate-resistant weeds. An experiment was conducted to analyze the transcriptome of A.

MicroRNA-target gene responses to root knot nematode (Meloidogyne incognita) infection in cotton (Gossypium hirsutum L.).

MicroRNAs (miRNAs) are a large class of small regulatory RNA molecules, however no study has been performed to elucidate the role of miRNAs in cotton (Gossypium hirsutum) response to the root knot nematode (RKN, Meloidogyne incognita) infection. We selected 28 miRNAs and 8 miRNA target genes to investigate the miRNA-target gene response to M. incognita infection.

Microbial Resistance Mechanisms to the Antibiotic and Phytotoxin Fusaric Acid.

Fusaric acid (FA) produced by Fusarium oxysporum plays an important role in disease development in plants, including cotton. This non-specific toxin also has antibiotic effects on microorganisms. Thus, one expects a potential pool of diverse detoxification mechanisms of FA in nature.

The genome of the cotton bacterial blight pathogen pv. strain MSCT1.

pv. is a major pathogen of cotton, L..

Genetic Diversity, Virulence, and Meloidogyne incognita Interactions of Fusarium oxysporum Isolates Causing Cotton Wilt in Georgia.

Locally severe outbreaks of Fusarium wilt of cotton (Gossypium spp.) in South Georgia raised concerns about the genotypes of the causal pathogen, Fusarium oxysporum f. sp.

Detoxification of Fusaric Acid by the Soil Microbe Mucor rouxii.

Fusarium oxysporum f. sp. vasinfectum race 4 (VCG0114), which causes root rot and wilt of cotton (Gossypium hirsutum and G.

Fine mapping and identification of candidate genes for a QTL affecting Meloidogyne incognita reproduction in Upland cotton.

Background: The southern root-knot nematode (Meloidogyne incognita; RKN) is one of the most important economic pests of Upland cotton (Gossypium hirsutum L.). Host plant resistance, the ability of a plant to suppress nematode reproduction, is the most economical, practical, and environmentally sound method to provide protection against this subterranean pest.

Resistance to PPO-inhibiting herbicide in Palmer amaranth from Arkansas.

Background: The widespread occurrence of ALS inhibitor- and glyphosate-resistant Amaranthus palmeri has led to increasing use of protoporphyrinogen oxidase (PPO)-inhibiting herbicides in cotton and soybean. Studies were conducted to confirm resistance to fomesafen (a PPO inhibitor), determine the resistance frequency, examine the resistance profile to other foliar-applied herbicides and investigate the resistance mechanism of resistant plants in a population collected in 2011 (AR11-LAW B) and its progenies from two cycles of fomesafen selection (C1 and C2).

Results: The frequency of fomesafen-resistant plants increased from 5% in the original AR11-LAW-B to 17% in the C2 population.

Identification and characterization of microRNAs in the plant parasitic root-knot nematode Meloidogyne incognita using deep sequencing.

The root-knot nematode Meloidogyne incognita is among the most damaging plant-parasitic pests of several crops including cotton (Gossypium hirsutum) and tomato (Lycopersicon escultentum). Recently, a genome has become available for M. incognita, which greatly facilitates investigation of the interactions between M.

Relationship Between Piercing-Sucking Insect Control and Internal Lint and Seed Rot in Southeastern Cotton (Gossypium hirsutum L.).

In 1999, crop consultants scouting for stink bugs (Hemiptera spp.) in South Carolina discovered a formerly unobserved seed rot of cotton that caused yield losses ranging from 10 to 15% in certain fields. The disease has subsequently been reported in fields throughout the southeastern Cotton Belt.

FUBT, a putative MFS transporter, promotes secretion of fusaric acid in the cotton pathogen Fusarium oxysporum f. sp. vasinfectum.

Fusaric acid (FA) is a key component in virulence and symptom development in cotton during infection by Fusarium oxysporum. A putative major facilitator superfamily (MFS) transporter gene was identified downstream of the polyketide synthase gene responsible for the biosynthesis of FA in a region previously believed to be unrelated to the known FA gene cluster. Disruption of the transporter gene, designated FUBT, resulted in loss of FA secretion, decrease in FA production and a decrease in resistance to high concentrations of FA.

Re-evaluation of the inheritance for root-knot nematode resistance in the Upland cotton germplasm line M-120 RNR revealed two epistatic QTLs conferring resistance.

We report a second major QTL for root-knot nematode resistance in the highly resistant Upland cotton line M-120RNR and show epistasis between two resistant QTLs with different mechanisms conferring resistance. In an earlier study, we identified a major QTL on Chromosome 11 associated with resistance to root-knot nematode in the M-120 RNR Upland cotton line (Gossypium hirsutum L.) of the Auburn 623 RNR source.