Efficacy of plant resistance inducers on cereal crops against a complex of pathogens

The article describes the benefits of using plant resistance inducers on cereal crops and the basic principles of their impact on pests development (Pyrenophora tritici-repentis, Puccinia triticina, Puccinia striiformis, Puccinia graminis, Puccinia hordei). The assessment results of the biological and economic effectiveness of L-479 and DL-59 preparations are presented in comparison with the chemical Kolosal,CE and biological Albit, which were used as standards for reducing the development of yellow leaf spot and rust diseases. L-479 product was found to be the most effective on wheat against brown, yellow and stem rust, and yellow leaf spot. Its biological efficacy ranged from 48.3 % to 57.0 % depending on the pathogen, and the increase in grain yield ranged from 3.7 % to 22.1 %. DL-59 product showed the best biological efficacy against dwarf leaf rust of barley – 89.8 %, the increase in grain yield was 3.5 %.

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Characterization of genetic loci conferring adult plant resistance to leaf rust and stripe rust in spring wheat

Genome ◽

10.1139/g06-052 ◽

2006 ◽

Vol 49 (8) ◽

pp. 977-990 ◽

Cited By ~ 110

Author(s):

H M William ◽

R P Singh ◽

J Huerta-Espino ◽

G Palacios ◽

K Suenaga

Keyword(s):

Leaf Rust ◽

Stripe Rust ◽

Plant Resistance ◽

Adult Plant Resistance ◽

Puccinia Striiformis ◽

Bulked Segregant Analysis ◽

Puccinia Triticina ◽

Adult Plant ◽

Single Chromosome ◽

Slow Rusting

Leaf (brown) and stripe (yellow) rusts, caused by Puccinia triticina and Puccinia striiformis, respectively, are fungal diseases of wheat (Triticum aestivum) that cause significant yield losses annually in many wheat-growing regions of the world. The objectives of our study were to characterize genetic loci associated with resistance to leaf and stripe rusts using molecular markers in a population derived from a cross between the rust-susceptible cultivar 'Avocet S' and the resistant cultivar 'Pavon76'. Using bulked segregant analysis and partial linkage mapping with AFLPs, SSRs and RFLPs, we identified 6 independent loci that contributed to slow rusting or adult plant resistance (APR) to the 2 rust diseases. Using marker information available from existing linkage maps, we have identified additional markers associated with resistance to these 2 diseases and established several linkage groups in the 'Avocet S' × 'Pavon76' population. The putative loci identified on chromosomes 1BL, 4BL, and 6AL influenced resistance to both stripe and leaf rust. The loci on chromosomes 3BS and 6BL had significant effects only on stripe rust, whereas another locus, characterized by AFLP markers, had minor effects on leaf rust only. Data derived from Interval mapping indicated that the loci identified explained 53% of the total phenotypic variation (R2) for stripe rust and 57% for leaf rust averaged across 3 sets of field data. A single chromosome recombinant line population segregating for chromosome 1B was used to map Lr46/Yr29 as a single Mendelian locus. Characterization of slow-rusting genes for leaf and stripe rust in improved wheat germplasm would enable wheat breeders to combine these additional loci with known slow-rusting loci to generate wheat cultivars with higher levels of slow-rusting resistance.Key words: Puccinia triticina, Puccinia striiformis, Triticum aestivum, bulked segregant analysis, single chromosome recombinant lines, linkage mapping, adult plant resistance.

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Laminarin Induces Defense Responses and Efficiently Controls Olive Leaf Spot Disease in Olive

Molecules ◽

10.3390/molecules26041043 ◽

2021 ◽

Vol 26 (4) ◽

pp. 1043

Author(s):

George T. Tziros ◽

Anastasios Samaras ◽

George S. Karaoglanidis

Keyword(s):

Leaf Spot ◽

Defense Responses ◽

Copper Accumulation ◽

Leaf Spot Disease ◽

Biological Control Agents ◽

Olive Leaf ◽

Control Efficacy ◽

Resistance Inducers ◽

Kinetics Of ◽

Potential Use

Olive leaf spot (OLS) caused by Fusicladiumoleagineum is mainly controlled using copper fungicides. However, the replacement of copper-based products with eco-friendly alternatives is a priority. The use of plant resistance-inducers (PRIs) or biological control agents (BCAs) could contribute in this direction. In this study we investigated the potential use of three PRIs (laminarin, acibenzolar-S-methyl, harpin) and a BCA (Bacillus amyloliquefaciens FZB24) for the management of OLS. The tested products provided control efficacy higher than 68%. In most cases, dual applications provided higher (p < 0.05) control efficacies compared to that achieved by single applications. The highest control efficacy of 100% was achieved by laminarin. Expression analysis of the selected genes by RT-qPCR revealed different kinetics of induction. In laminarin-treated plants, for most of the tested genes a higher induction rate (p < 0.05) was observed at 3 days post application. Pal, Lox, Cuao and Mpol were the genes with the higher inductions in laminarin-treated and artificially inoculated plants. The results of this study are expected to contribute towards a better understanding of PRIs in olive culture and the optimization of OLS control, while they provide evidence for potential contributions in the reduction of copper accumulation in the environment.

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Grass Hosts Harbor More Diverse Isolates of Puccinia striiformis Than Cereal Crops

Phytopathology ◽

10.1094/phyto-07-15-0155-r ◽

2016 ◽

Vol 106 (4) ◽

pp. 362-371 ◽

Cited By ~ 20

Author(s):

P. Cheng ◽

X. M. Chen ◽

D. R. See

Keyword(s):

Ssr Markers ◽

Stripe Rust ◽

Simple Sequence Repeat ◽

Puccinia Striiformis ◽

The United States ◽

Grass Species ◽

Cereal Crops ◽

Sequence Repeat ◽

Grass Hosts ◽

Simple Sequence

Puccinia striiformis causes stripe rust on cereal crops and many grass species. However, it is not clear whether the stripe rust populations on grasses are able to infect cereal crops and how closely they are related to each other. In this study, 103 isolates collected from wheat, barley, triticale, rye, and grasses in the United States were characterized by virulence tests and simple sequence repeat (SSR) markers. Of 69 pathotypes identified, 41 were virulent on some differentials of wheat only, 10 were virulent on some differentials of barley only, and 18 were virulent on some differentials of both wheat and barley. These pathotypes were clustered into three groups: group one containing isolates from wheat, triticale, rye, and grasses; group two isolates were from barley and grasses; and group three isolates were from grasses and wheat. SSR markers identified 44 multilocus genotypes (MLGs) and clustered them into three major molecular groups (MG) with MLGs in MG3 further classified into three subgroups. Isolates from cereal crops were present in one or more of the major or subgroups, but not all, whereas grass isolates were present in all of the major and subgroups. The results indicate that grasses harbor more diverse isolates of P. striiformis than the cereals.

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Forage and grain yield of grazed or defoliated spring and winter cereals in a winter-dominant, low-rainfall environment

Crop and Pasture Science ◽

10.1071/cp14273 ◽

2015 ◽

Vol 66 (4) ◽

pp. 308 ◽

Cited By ~ 10

Author(s):

Alison. J. Frischke ◽

James R. Hunt ◽

Dannielle K. McMillan ◽

Claire J. Browne

Keyword(s):

Grain Yield ◽

Dry Matter ◽

Cereal Crops ◽

Grain Production ◽

Forage Production ◽

Dual Purpose ◽

Winter Cereals ◽

Yield And Quality ◽

Eastern Australia ◽

Grain Yield And Quality

In the Mallee region of north-western Victoria, Australia, there is very little grazing of crops that are intended for grain production. The success of dual-purpose crops in other regions in south-eastern Australia with higher and more evenly distributed rainfall has driven interest in assessing the performance of dual-purpose cereals in the region. Five experiments were established in five consecutive years (2009–13) in the southern Mallee to measure the forage production and grain yield and quality response in wheat and barley to grazing by sheep or mechanical defoliation. The first three experiments focused on spring cultivars sown from late April to June, and the last two on winter cultivars planted from late February to early March. Cereal crops provided early and nutritious feed for livestock, with earlier sowing increasing the amount of dry matter available for winter grazing, and barley consistently produced more dry matter at the time of grazing or defoliation than wheat. However, the grain-production response of cereals to grazing or defoliation was variable and unpredictable. Effects on yield varied from –0.7 to +0.6 t/ha, with most site × year × cultivar combinations neutral (23) or negative (14), and few positive (2). Changes in grain protein were generally consistent with yield dilution effects. Defoliation increased the percentage of screenings (grains passing a 2-mm sieve) in three of five experiments. Given the risk of reduced grain yield and quality found in this study, and the importance of grain income in determining farm profitability in the region, it is unlikely that dual-purpose use of current cereal cultivars will become widespread under existing grazing management guidelines for dual-purpose crops (i.e. that cereal crops can be safely grazed once anchored, until Zadoks growth stage Z30, without grain yield penalty). It was demonstrated that early-sown winter wheat cultivars could produce more dry matter for grazing (0.4–0.5 t/ha) than later sown spring wheat and barley cultivars popular in the region (0.03–0.21 t/ha), and development of regionally adapted winter cultivars may facilitate adoption of dual-purpose cereals on mixed farms.

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The Effect of Hydrolysis and Protein Source on the Efficacy of Protein Hydrolysates as Plant Resistance Inducers against Powdery Mildew

Journal of Bioprocessing & Biotechniques ◽

10.4172/2155-9821.1000306 ◽

2017 ◽

Vol 07 (04) ◽

Cited By ~ 2

Author(s):

Martina Cappelletti ◽

Michele Perazzolli ◽

Andrea Nesler ◽

Oscar Giovannini ◽

Ilaria Pertot

Keyword(s):

Powdery Mildew ◽

Plant Resistance ◽

Protein Hydrolysates ◽

Protein Source ◽

Resistance Inducers

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Adult Plant Resistance in Maize to Northern Leaf Spot Is a Feature of Partial Loss-of-function Alleles ofHm1

10.1101/244491 ◽

2018 ◽

Author(s):

Sandeep R. Marla ◽

Kevin Chu ◽

Satya Chintamanani ◽

Dilbag Multani ◽

Antje Klempien ◽

...

Keyword(s):

Disease Resistance ◽

Resistance Genes ◽

Plant Resistance ◽

Leaf Spot ◽

Adult Plant Resistance ◽

Plant Diseases ◽

Adult Plant ◽

Hc Toxin ◽

Differential Transcription

ABSTRACTAdult plant resistance (APR) is an enigmatic phenomenon in which resistance genes are ineffective in protecting seedlings from disease but confer robust resistance at maturity. Maize has multiple cases in which genes confer APR to northern leaf spot, a lethal disease caused byCochliobolus carbonumrace 1 (CCR1). The first identified case of APR in maize is encoded by a hypomorphic allele,Hm1A, at thehm1locus. In contrast, wild type alleles ofhm1provide complete protection at all developmental stages and in every part of the maize plant.Hm1encodes an NADPH-dependent reductase, which inactivates HC-toxin, a key virulence effector of CCR1. Cloning and characterization ofHm1Aruled out differential transcription or translation for its APR phenotype and identified an amino acid substitution that reduced HC-toxin reductase (HCTR) activity. The possibility of a causal relationship between the weak nature ofHm1Aand its APR phenotype was confirmed by the generation of two new APR alleles ofHm1by mutagenesis. The HCTRs encoded by these new APR alleles had undergone relatively conservative missense changes that partially reduced their enzymatic activity similar to HM1A. No difference in accumulation of HCTR was observed between adult and juvenile plants, suggesting that the susceptibility of seedlings derives from a greater need for HCTR activity, not reduced accumulation of the gene product. Conditions and treatments that altered the photosynthetic output of the host had a dramatic effect on resistance imparted by the APR alleles, demonstrating a link between the energetic or metabolic status of the host and disease resistance affected by HC-toxin catabolism by the APR alleles of HCTR.AUTHOR SUMMARYAdult plant resistance (APR) is a phenomenon in which disease resistance genes are able to confer resistance at the adult stages of the plant but somehow fail to do so at the seedling stages. Despite the widespread occurrence of APR in various plant diseases, the mechanism underlying this trait remains obscure. It is not due to the differential transcription of these genes, and here we show that it is also not due to the differential translation or activity of the APR alleles of the maizehm1gene at different stages of development. Using a combination of molecular genetics, biochemistry and physiology, we present multiple lines of evidence that demonstrate that APR is a feature or symptom of weak forms of resistance. While the mature parts of the plant are metabolically robust enough to manifest resistance, seedling tissues are not, leaving them vulnerable to disease. Growth conditions that compromise the photosynthetic output of the plant further deteriorate the ability of the seedlings to protect themselves from pathogens.One sentence summaryCharacterization of adult plant resistance in the maize-CCR1 pathosystem reveals a causal link between weak resistance and APR.

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