Journal Article

Loss-of-Function Mutations in the Arabidopsis Heterotrimeric G-protein α Subunit Enhance the Developmental Defects of Brassinosteroid Signaling and Biosynthesis Mutants

Yajun Gao, Shucai Wang, Tadao Asami and Jin-Gui Chen

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 49, issue 7, pages 1013-1024
Published in print July 2008 | ISSN: 0032-0781
Published online May 2008 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pcn078
Loss-of-Function Mutations in the Arabidopsis Heterotrimeric G-protein α Subunit Enhance the Developmental Defects of Brassinosteroid Signaling and Biosynthesis Mutants

More Like This

Show all results sharing these subjects:

  • Biochemistry
  • Molecular and Cell Biology
  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Loss-of-function alleles of the sole heterotrimeric G-protein α subunit in Arabidopsis, GPA1, display defects in cell proliferation throughout plant development. Previous studies indicated that GPA1 is involved in brassinosteroid (BR) response. Here we provide genetic evidence that loss-of-function mutations in GPA1, gpa1-2 and gpa1-4, enhance the developmental defects of bri1-5, a weak allele of a BR receptor mutant, and det2-1, a BR-deficient mutant in Arabidopsis. gpa1-2 bri1-5 and gpa1-4 det2-1 double mutants had shorter hypocotyls, shorter roots and fewer lateral roots, and displayed more severe dwarfism than bri1-5 and det2-1 single mutants, respectively. By using the Arabidopsis hypocotyl as a model system where the parameters of cell division and cell elongation can be simultaneously measured, we found that gpa1 can specifically enhance the cell division defects of bri1-5 and det2-1 mutants. Similarly, gpa1 specifically enhances cell division defects in the primary roots of bri1-5 and det2-1 mutants. Furthermore, an additive effect on cell division between gpa1 and bri1-5 or det2-1 mutations was observed in the hypocotyls, whereas a synergistic effect was observed in the roots. Taken together, these results provided the first genetic evidence that G-protein- and BR-mediated pathways may be converged to modulate cell proliferation in a cell/tissue-specific manner.

Keywords: Arabidopsis; Brassinosteroid (BR); Cell proliferation; Heterotrimeric G-protein α subunit (GPA1); Hypocotyl; Root

Journal Article.  7272 words.  Illustrated.

Subjects: Biochemistry ; Molecular and Cell Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.