Du Seok Choi1,2, Chae Woo Lim1,3, Byung Kook Hwang4. 1. Laboratory of Molecular Plant Pathology, College of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul, 02841, Republic of Korea. 2. Department of Plant Pathology and Microbiology, University of California Riverside, Riverside, CA, 92521, USA. 3. Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea. 4. Laboratory of Molecular Plant Pathology, College of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul, 02841, Republic of Korea. bkhwang@korea.ac.kr.
Abstract
MAIN CONCLUSION: Proteomics and functional analyses of the Arabidopsis - Pseudomonas syringae pv. tomato interactions reveal that Arabidopsis nitrilases are required for plant defense and R gene-mediated resistant responses to microbial pathogens. A high-throughput in planta proteome screen has identified Arabidopsis nitrilase 2 (AtNIT2), which was de novo-induced by Pseudomonas syringae pv. tomato (Pst) infection. The AtNIT2, AtNIT3, and AtNIT4 genes, but not AtNIT1, were distinctly induced in Arabidopsis leaves by Pst infection. Notably, avirulent Pst DC3000 (avrRpt2) infection led to significant induction of AtNIT2 and AtNIT4 in leaves. Pst DC3000 and Pst DC3000 (avrRpt2) significantly grew well in leaves of nitrilase transgenic (nit2i-2) and mutant (nit1-1 and nit3-1) lines compared to the wild-type leaves. In contrast, NIT2 overexpression in nit2 mutants led to significantly high growth of the two Pst strains in leaves. The nitrilase transgenic and mutant lines exhibited enhanced susceptibility to Hyaloperonospora arabidopsidis infection. The nit2 mutation enhanced Pst DC3000 (avrRpt2) growth in salicylic acid (SA)-deficient NahG transgenic and sid2 and npr1 mutant lines. Infection with Pst DC3000 or Pst DC3000 (avrRpt2) induced lower levels of indole-3-acetic acid (IAA) in nit2i and nit2i NahG plants than in wild-type plants, but did not alter the IAA level in NahG transgenic plants. This suggests that Arabidopsis nitrilase 2 is involved in IAA signaling of defense and R gene-mediated resistance responses to Pst infection. Quantification of SA in these transgenic and mutant plants demonstrates that Arabidopsis nitrilase 2 is not required for SA-mediated defense response to the virulent Pst DC3000 but regulates SA-mediated resistance to the avirulent Pst DC3000 (avrRpt2). These results collectively suggest that Arabidopsis nitrilase genes are involved in plant defense and R gene-mediated resistant responses to microbial pathogens.
MAIN CONCLUSION: Proteomics and functional analyses of the Arabidopsis - Pseudomonas syringae pv. tomato interactions reveal that Arabidopsis nitrilases are required for plant defense and R gene-mediated resistant responses to microbial pathogens. A high-throughput in planta proteome screen has identified Arabidopsis nitrilase 2 (AtNIT2), which was de novo-induced by Pseudomonas syringae pv. tomato (Pst) infection. The AtNIT2, AtNIT3, and AtNIT4 genes, but not AtNIT1, were distinctly induced in Arabidopsis leaves by Pst infection. Notably, avirulent Pst DC3000 (avrRpt2) infection led to significant induction of AtNIT2 and AtNIT4 in leaves. Pst DC3000 and Pst DC3000 (avrRpt2) significantly grew well in leaves of nitrilase transgenic (nit2i-2) and mutant (nit1-1 and nit3-1) lines compared to the wild-type leaves. In contrast, NIT2 overexpression in nit2 mutants led to significantly high growth of the two Pst strains in leaves. The nitrilase transgenic and mutant lines exhibited enhanced susceptibility to Hyaloperonospora arabidopsidis infection. The nit2 mutation enhanced Pst DC3000 (avrRpt2) growth in salicylic acid (SA)-deficient NahG transgenic and sid2 and npr1 mutant lines. Infection with Pst DC3000 or Pst DC3000 (avrRpt2) induced lower levels of indole-3-acetic acid (IAA) in nit2i and nit2i NahG plants than in wild-type plants, but did not alter the IAA level in NahG transgenic plants. This suggests that Arabidopsis nitrilase 2 is involved in IAA signaling of defense and R gene-mediated resistance responses to Pst infection. Quantification of SA in these transgenic and mutant plants demonstrates that Arabidopsis nitrilase 2 is not required for SA-mediated defense response to the virulent Pst DC3000 but regulates SA-mediated resistance to the avirulent Pst DC3000 (avrRpt2). These results collectively suggest that Arabidopsis nitrilase genes are involved in plant defense and R gene-mediated resistant responses to microbial pathogens.
Authors: Anna Doskočilová; Lucie Kohoutová; Jindřich Volc; Hana Kourová; Oldřich Benada; Jana Chumová; Ondřej Plíhal; Beáta Petrovská; Petr Halada; László Bögre; Pavla Binarová Journal: New Phytol Date: 2013-02-25 Impact factor: 10.151
Authors: José M Alonso; Anna N Stepanova; Thomas J Leisse; Christopher J Kim; Huaming Chen; Paul Shinn; Denise K Stevenson; Justin Zimmerman; Pascual Barajas; Rosa Cheuk; Carmelita Gadrinab; Collen Heller; Albert Jeske; Eric Koesema; Cristina C Meyers; Holly Parker; Lance Prednis; Yasser Ansari; Nathan Choy; Hashim Deen; Michael Geralt; Nisha Hazari; Emily Hom; Meagan Karnes; Celene Mulholland; Ral Ndubaku; Ian Schmidt; Plinio Guzman; Laura Aguilar-Henonin; Markus Schmid; Detlef Weigel; David E Carter; Trudy Marchand; Eddy Risseeuw; Debra Brogden; Albana Zeko; William L Crosby; Charles C Berry; Joseph R Ecker Journal: Science Date: 2003-08-01 Impact factor: 47.728