SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 2 controls floral organ development and plant fertility by activating ASYMMETRIC LEAVES 2 in Arabidopsis thaliana.
A network of genes is coordinately expressed to ensure proper development of floral organs and fruits, which are essential for generating new offspring in flowering plants. In Arabidopsis thaliana, microRNA156 (miR156) plays a role in regulating the development of flowers and siliques by targeting members of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) gene family. Despite the important roles of the miR156/SPL network, our understanding of its downstream genes that are involved in floral organ and silique growth is still incomplete. Here, we report that the miR156/SPL2 regulatory pathway regulates pollen production, fertility rate, and the elongation of floral organs, including petals, sepals, and siliques in Arabidopsis. Transgenic plants exhibiting both overexpression of miR156 and dominant-negative alleles of SPL2 had reduced ASYMMETRIC LEAVES 2 (AS2) transcript levels in their siliques. Furthermore, their fertility phenotype was similar to that of the AS2 loss-of-function mutant. We also demonstrate that the SPL2 protein binds to the 5'UTR of the AS2 gene in vivo, indicating that AS2 is directly regulated by SPL2. Our results suggest that the miR156/SPL2 pathway affects floral organs, silique development and plant fertility, as well as directly regulates AS2 expression.
Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.|Department of Biology, University of Western Ontario, 1511 Richmond Street, London, ON, N6A 5B7, Canada.
Zhishuo
Z
Wang
Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.|Department of Biology, University of Western Ontario, 1511 Richmond Street, London, ON, N6A 5B7, Canada.|Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada.
Ying
Y
Wang
Department of Biology, University of Western Ontario, 1511 Richmond Street, London, ON, N6A 5B7, Canada.
Susanne E
SE
Kohalmi
Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.
Lisa
L
Amyot
Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada. abdelali.hannoufa@agr.gc.ca.|Department of Biology, University of Western Ontario, 1511 Richmond Street, London, ON, N6A 5B7, Canada. abdelali.hannoufa@agr.gc.ca.
Abdelali
A
Hannoufa
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins
AS2; Fertility; Floral organs; SPL2; Siliques; miR156