AUTHOR=Huang Mingkun , Hu Yilong , Liu Xu , Li Yuge , Hou Xingliang 

TITLE=Arabidopsis LEAFY COTYLEDON1 controls cell fate determination during post-embryonic development

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00955

DOI=10.3389/fpls.2015.00955

ISSN=1664-462X

ABSTRACT=<p><italic>Arabidopsis</italic> LEAFY COTYLEDON1 (LEC1) transcription factor is a master regulator that shapes plant embryo development and post-embryonic seedling establishment. Loss-of-function of <italic>LEC1</italic> alters the cotyledon identity, causing the formation of ectopic trichomes, which does not occur in wild-type seedlings, implying that LEC1 might regulate embryonic cell fate determination during post-embryonic development. To test this hypothesis, we compared the expression of trichome development-related genes between the wild-type and the <italic>lec1</italic> mutant. We observed that transcripts of GLABROUS1 (<italic>GL1</italic>), <italic>GL2</italic>, and <italic>GL3</italic>, genes encoding the positive regulators in trichome development, were significantly upregulated, while the TRICHOMELESS1 (<italic>TCL2</italic>), ENHANCER OF TRY AND CPC1 (<italic>ETC1</italic>), and <italic>ETC2</italic> genes, encoding the negative regulators in trichome development, were downregulated in the <italic>lec1</italic> mutant. Furthermore, overexpression of <italic>LEC1</italic> activated the expressions of <italic>TCL2</italic>, CAPPICE (<italic>CPC</italic>), and <italic>ETC1</italic>, resulting in production of cotyledonary leaves with no or fewer trichomes during vegetative development. In addition, we demonstrated that LEC1 interacts with TCL2 in yeast and <italic>in vitro</italic>. A genetic experiment showed that loss-of-function of <italic>GL2</italic> rescued the ectopic trichome formation in the <italic>lec1</italic> mutant. These findings strongly support that LEC1 regulates trichome development, providing direct evidence for the role of LEC1 in cell fate determination during post-embryonic development.</p>