scholarly journals Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function

2008 ◽  
Vol 21 (1) ◽  
pp. 30-39 ◽  
Author(s):  
Yuling Bai ◽  
Stefano Pavan ◽  
Zheng Zheng ◽  
Nana F. Zappel ◽  
Anja Reinstädler ◽  
...  

The resistant cherry tomato (Solanum lycopersicum var. cerasiforme) line LC-95, derived from an accession collected in Ecuador, harbors a natural allele (ol-2) that confers broad-spectrum and recessively inherited resistance to powdery mildew (Oidium neolycopersici). As both the genetic and phytopathological characteristics of ol-2–mediated resistance are reminiscent of powdery mildew immunity conferred by loss-of-function mlo alleles in barley and Arabidopsis, we initiated a candidate-gene approach to clone Ol-2. A tomato Mlo gene (SlMlo1) with high sequence-relatedness to barley Mlo and Arabidopsis AtMLO2 mapped to the chromosomal region harboring the Ol-2 locus. Complementation experiments using transgenic tomato lines as well as virus-induced gene silencing assays suggested that loss of SlMlo1 function is responsible for powdery mildew resistance conferred by ol-2. In progeny of a cross between a resistant line bearing ol-2 and the susceptible tomato cultivar Moneymaker, a 19-bp deletion disrupting the SlMlo1 coding region cosegregated with resistance. This polymorphism results in a frameshift and, thus, a truncated nonfunctional SlMlo1 protein. Our findings reveal the second example of a natural mlo mutant that possibly arose post-domestication, suggesting that natural mlo alleles might be evolutionarily short-lived due to fitness costs related to loss of mlo function.

2011 ◽  
Vol 12 (9) ◽  
pp. 866-878 ◽  
Author(s):  
MATT HUMPHRY ◽  
ANJA REINSTÄDLER ◽  
SERGEY IVANOV ◽  
TON BISSELING ◽  
RALPH PANSTRUGA

2005 ◽  
Vol 138 (4) ◽  
pp. 2155-2164 ◽  
Author(s):  
Ingo Hein ◽  
Maria Barciszewska-Pacak ◽  
Katarina Hrubikova ◽  
Sandie Williamson ◽  
Malene Dinesen ◽  
...  

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuli Jin ◽  
Hongxing Xu ◽  
Pengtao Ma ◽  
Xiaoyi Fu ◽  
Liping Song ◽  
...  

2018 ◽  
Vol 70 (3) ◽  
pp. 513-520
Author(s):  
Ibrahim Ozturk ◽  
Figen Ersoy ◽  
Mahinur Akkaya

Powdery mildew disease, caused by Blumeria graminis f. sp. hordei (Bgh), which belongs to the order Erysiphales, is a major crop disease. The general control nondepressible-2 (GCN2) gene of barley was previously found to be overexpressed during the powdery mildew resistance response. Recently, Arabidopsis thaliana GCN2 (AtGCN2) was shown to be involved in disease resistance against biotrophic and necrotrophic pathogens. In order to understand the function of Hordeum vulgare GCN2 (HvGCN2) in the barley powdery mildew resistance response, this gene was silenced by barley stripe mosaic virus (BSMV), mediated by virus-induced gene silencing (VIGS). This is the first study showing the potential importance of HvGCN2 in powdery mildew disease of barley. Based on our observations, when HvGCN2 was silenced on average by 53.5%, Bgh development was increased by 18.7 to 32.1%, which was determined by primary, secondary and longest hyphae measurements. The number of germinated spores also increased 2.8-fold in HvGCN2 silenced plants compared to control plants (BSMV:00). On the other hand, under the resistant condition, no difference was observed in HvGCN2- silenced plants compared to non-silenced lines although the gene was found to be overexpressed in incompatible interaction.


Genome ◽  
2018 ◽  
Vol 61 (10) ◽  
pp. 703-712 ◽  
Author(s):  
Daeun Kim ◽  
Bingkui Jin ◽  
Byoung Il Je ◽  
Youngmi Choi ◽  
Byung Sup Kim ◽  
...  

Reductions in growth and quality due to powdery mildew (PM) disease cause significant economic losses in tomato production. Oidium neolycopersici was identified as the fungal species responsible for tomato PM disease in South Korea in the present study, based on morphological and internal transcribed spacer DNA sequence analyses of PM samples collected from two remote regions (Muju and Miryang). The genes involved in resistance to this pathogen in the tomato accession ‘KNU-12’ (Solanum lycopersicum var. cerasiforme) were evaluated, and the inheritance of PM resistance in ‘KNU-12’ was found to be conferred via simple Mendelian inheritance of a mutant allele of the PM susceptibility locus Ol-2 (SlMlo1). Full-length cDNA analysis of this newly identified mutant allele (Slmlo1.1) showed that a 1-bp deletion in its coding region led to a frameshift mutation possibly resulting in SlMlo1 loss-of-function. An alternatively spliced transcript of Slmlo1.1 was observed in the cDNA sequences of ‘KNU-12’, but its direct influence on PM resistance is unclear. A derived cleaved amplified polymorphic sequence (dCAPS) and a high-resolution melting (HRM) marker were developed based on the 1-bp deletion in Slmlo1.1, and could be used for efficient marker-assisted selection (MAS) using ‘KNU-12’ as the source for durable and broad-spectrum resistance to PM.


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