Abstract Detail

Gene Structure and Function

Tian, Chang-en [1], Zhou, Yu-Ping [2], Duan, Jun [3], Fujibe, Takahiro  [4], Yamamoto, Kotaro [5].

AtIQM1, a Novel Calmodulin-Binding Protein, is Involved in Stomatal Movement.

We recently identified a novel IQ motif-containing protein family, IQM, which share sequence homology with a pea heavy metal-induced protein 6 and a ribosome inactivating protein, trichosanthin. Distinct expression patterns for each gene suggest that each IQM family member may play a different role in plant development and response to environmental cues. However functions of the IQM family members remain to be analyzed. IQM1 bound with CaM5 in yeast two-hybrid assay via its IQ-motif. The CaM binding was Ca²⁺-independent in vitro, and was also observed in bimolecular fluorescence complementation analyses in onion epidermal cells. IQM1 was found to express strongly in guard cells and the cortex of roots. The T-DNA insertion mutants of IQM1 displayed a smaller stomatal aperture, a decreased water loss rate and a shorter primary root. Moreover, iqm1 did not change its stomatal aperture when treated with light, dark, ABA and chitin obviously. Interestingly, 243 and 28 genes were up- and down-regulated by more than two fold in iqm1-1, respectively. Particularly, 34 of 117 and 7 of 30 chitin-responsive transcriptional factor and ubiquitin ligase genes were upregulated. iqm1-1 also showed enhanced expression of genes involved in production and signaling of reactive oxygen species (ROS) in guard cells. Consistently, increased ROS level was observed in guard cells.

Broader Impacts:

1 - Guangzhou University, Guangzhou Key Laboratory for Functional Study on Plant Stress-Resistant Genes, #230 Wai Huan Xi Road, GuangZhou Higher Education Mega Center, Guangzhou , 510006, P.R. China
2 - Guangzhou University, Guangzhou Key Laboratory for Functional Study on Plant Stress-Resistant Genes, #230 Wai Huan Xi Road, GuangZhou Higher Education Mega Center, Guangzhou, 510006, P.R. China
3 - Chinese Academy of Sciences, South China Botanical Garden , Guangzhou, 510650, P.R. China
4 - Hokkaido University, Department of Biological Sciences, Faculty of Science, Sapporo , 060-0810, Japan
5 - Hokkaido University, Faculty Of Science, Kita 10, Nishi 8, Sapporo, N/A, 060-0810, Japan

Keywords:
IQM1
Stomatal movement
Reactive oxygen species
Calmodulin-binding protein
Arabidopsis thaliana.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM
Number: PGS002
Abstract ID:134