NIMA-related kinases regulate directional cell growth and organ development through microtubule function in Arabidopsis thaliana.
NIMA-related kinase 6 (NEK6) regulates cellular expansion and morphogenesis through microtubule organizaiton in Arabidopsis thaliana. Loss-of-function mutations in NEK6 (nek6/ibo1) cause ectopic outgrowth and microtubule disorganization in epidermal cells. We recently found that NEK6 forms homodimers and heterodimers with NEK4 and NEK5 to destabilize cortical microtubules possibly by direct binding to microtubules and the β-tubulin phosphorylation. Here, we identified a new allele of NEK6 and further analyzed the morphological phenotypes of nek6/ibo1 mutants, along with alleles of nek4 and nek5 mutants. Phenotypic analysis demonstrated that NEK6 is required for the directional growth of roots and hypocotyls, petiole elongation, cell file formation, and trichome morphogenesis. In addition, nek4, nek5, and nek6/ibo1 mutants were hypersensitive to microtubule inhibitors such as propyzamide and taxol. These results suggest that plant NEKs function in directional cell growth and organ development through the regulation of microtubule organization.
Division of Biological Sciences, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan. motose@bio.c.okayama-u.ac.jp
Hiroyasu
H
Motose
Shogo
S
Takatani
Tatsuya
T
Ikeda
Taku
T
Takahashi
D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001549:Benzamides / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018546:Hypocotyl / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D000072379:NIMA-Related Kinases; D017239:Paclitaxel / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; D001549:Benzamides; C001059:pronamide; D011494:Protein Kinases; D000072379:NIMA-Related Kinases; C570509:Nek4 protein, Arabidopsis; C570510:Nek5 protein, Arabidopsis; C570508:Nek6 protein, Arabidopsis; D017239:Paclitaxel