Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

NAC Family Proteins NARS1/NAC2 and NARS2/NAM in the Outer Integument Regulate Embryogenesis in Arabidopsis

Tadashi Kunieda, Nobutaka Mitsuda, Masaru Ohme-Takagi, Seiji Takeda, Mitsuhiro Aida, Masao Tasaka, Maki Kondo, Mikio Nishimura and Ikuko Hara-Nishimura
The Plant Cell
Vol. 20, No. 10 (Oct., 2008), pp. 2631-2642
Stable URL: http://www.jstor.org/stable/25224371
Page Count: 12
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
NAC Family Proteins NARS1/NAC2 and NARS2/NAM in the Outer Integument Regulate Embryogenesis in Arabidopsis
Preview not available

Abstract

Seed morphogenesis consists of embryogenesis and the development of maternal tissues such as the inner and outer integuments, both of which give rise to seed coats. We show that expression of chimeric repressors derived from NAC-REGULATED SEED MORPHOLOGY1 and -2 (NARS1 and NARS2, also known as NAC2 and NAM, respectively) caused aberrant seed shapes in Arabidopsis thaliana. Double knockout mutant nars1 nars2 exhibited abnormally shaped seeds; moreover, neither nars1 nor nars2 produced abnormal seeds, indicating that NARS1 and NARS2 redundantly regulate seed morphogenesis. Degeneration of the integuments in nars1 nars2 was markedly delayed, while that of the wild type occurred around the torpedo-shaped embryo stage. Additionally, nars1 nars2 showed a defect in embryogenesis: some nars1 nars2 embryos were developmentally arrested at the torpedo-shaped embryo stage. Unexpectedly, however, neither NARS1 nor NARS2 was expressed in the embryo at this stage, although they were found to be expressed in the outer integument. Wild-type pistils pollinated with nars1 nars2 pollen generated normal seeds, while the reverse crossing generated abnormal seeds. Taken together, these results indicate that NARS1 and NARS2 regulate embryogenesis by regulating the development and degeneration of ovule integuments. Our findings suggest that there is an intertissue communication between the embryo and the maternal integument.

Page Thumbnails

  • Thumbnail: Page 
[2631]
    [2631]
  • Thumbnail: Page 
2632
    2632
  • Thumbnail: Page 
2633
    2633
  • Thumbnail: Page 
2634
    2634
  • Thumbnail: Page 
2635
    2635
  • Thumbnail: Page 
2636
    2636
  • Thumbnail: Page 
2637
    2637
  • Thumbnail: Page 
2638
    2638
  • Thumbnail: Page 
2639
    2639
  • Thumbnail: Page 
2640
    2640
  • Thumbnail: Page 
2641
    2641
  • Thumbnail: Page 
2642
    2642