<i>PagGRF11</i> Overexpression Promotes Stem Development and Dwarfing in <i>Populus</i>
Poplar is not only an important woody plant, but also a model species for molecular plant studies. We identified <i>PagGRF11</i> (pAxG07Gg0005700), a homolog of the Arabidopsis <i>AtGRF1</i> (AT4G37740) and <i>A</i><i>tGRF2</i> (AT2G22840) gene. We tra...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-07-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/23/14/7858 |
| Summary: | Poplar is not only an important woody plant, but also a model species for molecular plant studies. We identified <i>PagGRF11</i> (pAxG07Gg0005700), a homolog of the Arabidopsis <i>AtGRF1</i> (AT4G37740) and <i>A</i><i>tGRF2</i> (AT2G22840) gene. We transformed the poplar clone “84K” with <i>PagGRF11</i>, and the transgenic overexpressed plants (<i>PagGRF11-OE</i>) showed plant height reduction (dwarfing), stem diameter increase, internode shortening, and larger leaf area. The <i>Arabidopsis</i> overexpression line <i>grf-oe</i> (Overexpression of <i>PagGRF11</i> in <i>Arabidopsis</i>), mutant line <i>atgrf</i> (<i>a loss-of-function mutant of the AtGRF1 gene of Arabidopsis thaliana</i>), and mutant trans-complementary line <i>atgrf+oe</i> (<i>overexpression of PagGRF11 in mutant plants</i> (<i>atgrf</i>)) also showed different leaf size phenotypes. Further, tissue sections revealed that increased xylem production was the main cause of stem thickening. Transcriptome differential expression analysis of <i>PagGRF11</i> overexpressed and control plants showed that <i>PagGRF11</i> promoted <i>CCCH39</i>(<i>C3H39</i>) expression. The expression profile of <i>CCCH39</i> in different tissues showed that it was highly expressed in xylem. Yeast single hybrid and instantaneous double luciferase assay results showed that <i>PagGRF11</i> directly transcribed and activated <i>CCCH39</i> expression through interaction with cis-acting element GARE (TCTGTTG), thus promoting xylem development. This is the first finding that GRF positively regulates xylem development through <i>CCCH39</i> expression activation and further suggests that <i>PagGRF11</i> is a potential target for increasing wood yield. |
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| ISSN: | 1661-6596 1422-0067 |