Format

Send to

Choose Destination
Plant Cell. 2018 Feb;30(2):324-346. doi: 10.1105/tpc.17.00705. Epub 2018 Jan 25.

AUXIN RESPONSE FACTOR3 Regulates Floral Meristem Determinacy by Repressing Cytokinin Biosynthesis and Signaling.

Zhang K1,2,3, Wang R4, Zi H3,5, Li Y1,2, Cao X3,6, Li D1,2, Guo L1,2, Tong J4, Pan Y7, Jiao Y6, Liu R5, Xiao L4, Liu X8,2.

Author information

1
State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050024, China.
2
Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang 050024, China.
3
University of Chinese Academy of Sciences, Beijing 100049, China.
4
Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, 410128 Changsha, China.
5
Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai 201602, China.
6
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China.
7
College of Life Sciences, Hebei Agricultural University, Baoding 071001, China.
8
State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050024, China xgliu@sjziam.ac.cn.

Abstract

Successful floral meristem (FM) determinacy is critical for subsequent reproductive development and the plant life cycle. Although the phytohormones cytokinin and auxin interact to coregulate many aspects of plant development, whether and how cytokinin and auxin function in FM determinacy remain unclear. Here, we show that in Arabidopsis thaliana, cytokinin homeostasis is critical for FM determinacy. In this developmental context, auxin promotes the expression of AUXIN RESPONSE FACTOR3 (ARF3) to repress cytokinin activity. ARF3 directly represses the expression of ISOPENTENYLTRANSFERASE (IPT) family genes and indirectly represses LONELY GUY (LOG) family genes, both of which encode enzymes required for cytokinin biosynthesis. ARF3 also directly inhibits the expression of ARABIDOPSIS HISTIDINE KINASE4, a cytokinin receptor gene, resulting in reduced cytokinin activity. Consequently, ARF3 controls cell division by regulating cell cycle gene expression through cytokinin. In flowers, we show that AGAMOUS (AG) dynamically regulates the expression of ARF3 and IPTs, resulting in coordinated regulation of FM maintenance and termination through cell division. Moreover, genome-wide transcriptional profiling revealed both repressive and active roles for ARF3 in early flower development. Our findings establish a molecular link between AG and auxin/cytokinin and shed light on the mechanisms of stem cell maintenance and termination in the FM.

PMID:
29371438
PMCID:
PMC5868698
DOI:
10.1105/tpc.17.00705
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center