Coil-dependent signaling pathway is not required for Mi-1-mediated potato aphid resistance.
Tomato (Solanum lycopersicum) has a unique resistance gene, Mi-1, that confers resistance to animals from distinct taxa, nematodes, and piercing and sucking insects. Mi-1 encodes a protein with a nucleotide-binding site and leucine-rich repeat motifs. Early in the potato aphid (Macrosiphum euphorbiae)--tomato interactions, aphid feeding induces the expression of the jasmonic acid (JA)-regulated proteinase inhibitor genes, Pin1 and Pin2. The jail-1 (jasmonic acid insensitive 1) tomato mutant, which is impaired in JA perception, was used to gain additional insight into the JA signaling pathway and its role in the Mi-1-mediated aphid resistance. The jail-1 mutant has a deletion in the Coil gene that encodes a putative F-box protein. In this study, aphid colonization, survival, and fecundity were compared on wild-type tomato and jail-1 mutant. In choice assays, the jail-1 mutant showed higher colonization by potato aphids compared with wild-type tomato. In contrast, no-choice assays showed no difference in potato aphid survival or fecundity between jail-1 and the wild-type parent. Plants homozygous for Mi-1 and for the jail mutation were not compromised in resistance to potato aphids, using either choice or no-choice assays. In addition, the accumulation of JA-regulated Pin1 transcripts after aphid feeding was Coil dependent. Taken together, these data indicate that, although potato aphids activate Coil-dependent defense response in tomato, this response is not required for Mi-1-mediated resistance to aphids.
Bhattarai
Kishor K
KK
Department of Nematology, University of California, Riverside, CA 92521, USA.
Xie
Qi-Guang
QG
Pourshalimi
Daniel
D
Younglove
Ted
T
Kaloshian
Isgouhi
I
D000818:Animals; D001042:Aphids / Q000254:growth & development*; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005838:Genotype; D007113:Immunity, Innate / Q000235:genetics; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism / Q000469:parasitology; D054883:Oxylipins; D010935:Plant Diseases / Q000235:genetics* / Q000469:parasitology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D030821:Plants, Genetically Modified; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism / Q000469:parasitology
D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid