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The protein kinase genes MAP3K ɛ 1 and MAP3K ɛ 2 are required for pollen viability in Arabidopsis thaliana
Author(s) -
Chaiwongsar Suraphon,
Otegui Marisa S.,
Jester Peter J.,
Monson Sean S.,
Krysan Patrick J.
Publication year - 2006
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2006.02863.x
Subject(s) - arabidopsis , biology , arabidopsis thaliana , mutant , microbiology and biotechnology , pollen , map kinase kinase kinase , protein kinase a , kinase , genetics , gene , botany
Summary We have used reverse‐genetic analysis to investigate the function of MAP3K ɛ 1 and MAP3K ɛ 2 , a pair of closely related Arabidopsis thaliana genes that encode protein kinases. Plants homozygous for either map3k ɛ 1 or map3k ɛ 2 displayed no apparent mutant phenotype, whereas the double‐mutant combination caused pollen lethality. Transmission of the double‐mutant combination through the female gametophyte was normal. Tetrad analysis performed using the Arabidopsis quartet mutation demonstrated that the pollen‐lethal phenotype segregated at meiosis with the map3k ɛ 1;map3k ɛ 2 genotype. We used transmission electron microscopy to determine that double‐mutant pollen grains develop plasma membrane irregularities following pollen mitosis I. Analysis of the subcellular localization of a yellow fluorescent protein (YFP):MAP3K ɛ 1 fusion protein using confocal microscopy and biochemical fractionation indicated that a substantial portion of the MAP3K ɛ 1 present in Arabidopsis cells is localized to the plasma membrane. Taken together, our results suggest that MAP3K ɛ 1 is required for the normal functioning of the plasma membrane in developing Arabidopsis pollen.