Details

Autor(en) / Beteiligte

• Kim, Dachan
• Cho, Young‐hyun
• Ryu, Hojin
• Kim, Yoonhee
• Kim, Tae‐Houn
• Hwang, Ildoo

Titel

BLH 1 and KNAT 3 modulate ABA responses during germination and early seedling development in Arabidopsis

Ist Teil von

• The Plant journal : for cell and molecular biology, 2013-09, Vol.75 (5), p.755-766

Erscheinungsjahr

2013

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Summary The signal transduction pathway governed by the phytohormone abscisic acid ( ABA ) regulates not only abiotic stress responses but also early developmental programs such as seed dormancy, germination and seedling growth in response to environmental signals. Optimal plant growth and development depend on the integration of environmental stimuli and intrinsic developmental programs. Here, we show that the homeodomain transcription factors BLH 1 and KNAT 3, previously implicated in embryo sac development, have additional functions in ABA ‐mediated seed dormancy and early seedling development. The ABA ‐dependent induction of BLH 1 and KNAT 3 expression required the presence of functional PYR / PYL / RCAR receptors. The blh1 and knat3 mutants were less sensitive than the wild‐type to ABA or salinity exposure during seed germination and early seedling development. In contrast, BLH 1 over‐expressing lines were hypersensitive to ABA and salinity, and exhibited increased expression of ABA ‐responsive genes, such as ABI 3 and ABI 5 . BLH 1 interacted with KNAT 3 and enhanced the retention of KNAT 3 in the nucleus. BLH 1 and KNAT 3 synergistically increased the ABA responses by binding to and subsequently activating the ABI 3 promoter. Taken together, we propose that BLH 1 and KNAT 3 together modulate seed germination and early seedling development by directly regulating ABI 3 expression.