The Combined Action of ENHANCED DISEASE SUSCEPTIBILITY1, PHYTOALEXIN DEFICIENT4, and SENESCENCE-ASSOCIATED101 Promotes Salicylic Acid-Mediated Defenses to Limit Fusarium graminearum Infection in Arabidopsis thaliana.
Fusarium graminearum causes Fusarium head blight (FHB) disease in wheat and other cereals. F. graminearum also causes disease in Arabidopsis thaliana. In both Arabidopsis and wheat, F. graminearum infection is limited by salicylic acid (SA) signaling. Here, we show that, in Arabidopsis, the defense regulator EDS1 (ENHANCED DISEASE SUSCEPTIBILITY1) and its interacting partners, PAD4 (PHYTOALEXIN-DEFICIENT4) and SAG101 (SENESCENCE-ASSOCIATED GENE101), promote SA accumulation to curtail F. graminearum infection. Characterization of plants expressing the PAD4 noninteracting eds1(L262P) indicated that interaction between EDS1 and PAD4 is critical for limiting F. graminearum infection. A conserved serine in the predicted acyl hydrolase catalytic triad of PAD4, which is not required for defense against bacterial and oomycete pathogens, is necessary for limiting F. graminearum infection. These results suggest a molecular configuration of PAD4 in Arabidopsis defense against F. graminearum that is different from its defense contribution against other pathogens. We further show that constitutive expression of Arabidopsis PAD4 can enhance FHB resistance in Arabidopsis and wheat. Taken together with previous studies of wheat and Arabidopsis expressing salicylate hydroxylase or the SA-response regulator NPR1 (NON-EXPRESSER OF PR GENES1), our results show that exploring fundamental processes in a model plant provides important leads to manipulating crops for improved disease resistance.
1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A.;|2 Department of Plant Sciences, University of Hyderabad, Gachibowli, Hyderabad, India;
Ragiba
R
Makandar
1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A.;|3 Department of Biology, Indiana University-Purdue University, Fort Wayne, IN 46805, U.S.A.;
Vamsi J
VJ
Nalam
1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A.;
Zulkarnain
Z
Chowdhury
1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A.;
Sujon
S
Sarowar
1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A.;
Guy
G
Klossner
4 Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, U.S.A.;
Hyeonju
H
Lee
4 Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, U.S.A.;
Dehlia
D
Burdan
4 Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, U.S.A.;
Harold N
HN
Trick
5 Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions, Carl von Linné Weg 10, 50829 Cologne, Germany.
Enrico
E
Gobbato
5 Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions, Carl von Linné Weg 10, 50829 Cologne, Germany.
Jane E
JE
Parker
1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A.;
Jyoti
J
Shah
D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D060467:Disease Resistance; D005670:Fusarium / Q000472:pathogenicity*; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology; D020156:Salicylic Acid / Q000378:metabolism; D012694:Serine / Q000378:metabolism
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C118837:EDS1 protein, Arabidopsis; D012694:Serine; D002265:Carboxylic Ester Hydrolases; C400766:PAD4 protein, Arabidopsis; C460108:SAG101 protein, Arabidopsis; D020156:Salicylic Acid