Premium
Genetic interaction and phenotypic analysis of the Arabidopsis MAP kinase pathway mutations mekk1 and mpk4 suggests signaling pathway complexity
Author(s) -
Su Shih-Heng,
Suarez-Rodriguez Maria Cristina,
Krysan Patrick
Publication year - 2007
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2007.05.083
Subject(s) - arabidopsis , phenotype , biology , genetics , functional analysis , arabidopsis thaliana , kinase , signal transduction , microbiology and biotechnology , computational biology , gene , mutant
It has been shown that the Arabidopsis MEK kinase MEKK1 acts upstream of the MAP kinase MPK4 to negatively regulate salicylic acid‐dependent defense‐response pathways. Here, we report that the mekk1 ; mpk4 double‐mutant combination causes seedling lethality. In addition, we demonstrate that mekk1 and mpk4 single‐mutant plants have significantly different phenotypes. mekk1 plants are defective for lateral root formation, while mpk4 plants are not. In addition, treatment with elevated levels of sodium chloride improves the growth of mekk1 plants, while it inhibits the growth of mpk4 plants. Our results suggest that MEKK1 and MPK4 functions are not limited to a single, linear signaling pathway. Instead there appears to be more complexity to the signaling pathways in which these two proteins function.