Abstract Detail

Cell biology

Guo, Hongyan [1], Zhang, Wei [1], Liu, Bao [1], Wang, Shucai [1].

OsCLE48, an auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis.

Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance and tropisms. It is very likely that Auxin regulated plant growth and development is initiated by the activation of auxin response genes by local increased auxin concentration. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin. The relationship between auxin and peptide hormones remains largely unknown. CLE peptides are encoded by a big gene family in both Arabidopsis and rice. However, no CLE genes have been identified as auxin response gene. Here we report the identification of OsCLE48, a rice (Oryza sativa) CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION) gene, as an auxin response gene, and the functional characterization of OsCLE48 in Arabidopsis and rice. OsCLE48 encodes a CLE peptide hormone that is similar to Arabidopsis CLEs. RT-PCR analysis showed that OsCLE48 was induced by exogenously application of IAA (indole-3-acetic acid), a naturally occurred auxin. Expression of integrated OsCLE48p:GUS reporter gene in transgenic Arabidopsis plants was also induced by exogenously IAA treatment. These results indicate that OsCLE48 is an auxin responsive gene. Histochemical staining showed that GUS activity was detected in all the tissue and organs of the OsCLE48p:GUS transgenic Arabidopsis plants. Expression of OsCLE48 under the control of the 35S promoter in Arabidopsis inhibited shoot apical meristem development. Expression of OsCLE48 under the control of the CLV3 native regulatory elements almost completely complemented clv3-2 mutant phenotypes, suggesting that OsCLE48 is functionally similar to CLV3. On the other hand, expression of OsCLE48 under the control of the 35S promoter in Arabidopsis has little, if any effects on root apical meristem development, and transgenic rice plants overexpressing OsCLE48 are morphologically indistinguishable from wild type plants, suggesting that the functions of some CLE peptides may not be fully conserved in Arabidopsis and rice. Taken together, our results showed that OsCLE48 is an auxin responsive peptide hormone gene, and it regulates shoot apical meristem development when expressed in Arabidopsis.

1 - Northeast Normal University, School of Life Sciences, 5628 Renmin St., Changchun, Jinlin, 130024, China

Keywords:
CLE pepteide
auxin
Apical meristem development
Arabidopsis
rice.

Presentation Type: Oral Paper:Papers for Topics
Session: 58
Location: Salon 17/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 9:30 AM
Number: 58007
Abstract ID:352
Candidate for Awards:None