中文 |

Research Progress

Study Reveals Roles of VQ Motif-containing Proteins in Abscisic Acid Signaling

May 22, 2018

Seed germination and subsequent seedling establishment are crucial developmental stages during the life cycle of higher plants. They are modulated by diverse endogenous hormones and the surrounding environment.  

Arabidopsis ABSCISIC ACIDINSENSITIVE5 (ABI5) is a central transcription factor of abscisic acid (ABA) signaling that represses those processes. ABI5 is precisely modulated at posttranslational level. However, whether it interacts with other crucial transcriptional regulators remains to be investigated. 

Prof. YU Diqiu and his team of Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences reported in the Plant Journal that VQ18 and VQ26 function antagonistically with ABI5 to maintain the appropriate ABA signaling level necessary to fine-tune seed germination and subsequent seedling establishment. 

The researchers used the yeast two-hybrid (Y2H) assay to identify VQ18 and VQ26 as interacting partners of the ABI5 transcription factor. They found that VQ18 and VQ26 genes are predominantly expressed in germinating seeds and induced by ABA. 

Further analysis showed that VQ18 and VQ26 formed a complex with ABI5 in the nucleus. Decreasing the expression of VQ18 and VQ26 simultaneously enhanced ABA responses during seed germination. The overexpression of VQ18 or VQ26 conferred germinating seeds being less ABA-sensitive 

Consistently, the expression levels of several regulons of ABI5 were modulated by VQ18 and VQ26 in response to ABA. The increased ABA signaling of plants in which VQ18 and VQ26 were simultaneously suppressed required ABI5. 

Additionally, VQ18 and VQ26 acted as negative interactors of the ABI5 transcription factor. The overexpression of VQ18 or VQ26 rendered germinating seeds less sensitive to ABA compared with wild-type. 

Contact Us
  • 86-10-68597521 (day)

    86-10-68597289 (night)

  • 86-10-68511095 (day)

    86-10-68512458 (night)

  • cas_en@cas.cn

  • 52 Sanlihe Rd., Xicheng District,

    Beijing, China (100864)

Copyright © 2002 - Chinese Academy of Sciences