Genotype-Dependent Effect of Silencing of <i>TaCKX1</i> and <i>TaCKX2</i> on Phytohormone Crosstalk and Yield-Related Traits in Wheat
The influence of silenced <i>TaCKX1</i> and <i>TaCKX2</i> on coexpression of other <i>TaCKX</i> gene family members (GFMs), phytohormone regulation and yield-related traits was tested in awned-spike cultivar. We documented a strong feedback mechanism of regulation...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-10-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/21/11494 |
| Summary: | The influence of silenced <i>TaCKX1</i> and <i>TaCKX2</i> on coexpression of other <i>TaCKX</i> gene family members (GFMs), phytohormone regulation and yield-related traits was tested in awned-spike cultivar. We documented a strong feedback mechanism of regulation of <i>TaCKX</i> GFM expression in which silencing of <i>TaCKX1</i> upregulated expression of <i>TaCKX2</i> genes and vice versa. Additionally, downregulation of <i>TaCKX2</i> highly upregulated the expression of <i>TaCKX5</i> and <i>TaNAC2-5A</i>. In contrast, expression of these genes in silenced <i>TaCKX1</i> was downregulated. Silenced <i>TaCKX1</i> T<sub>2</sub> lines with expression decreased by 47% had significantly higher thousand grain weight (TGW) and seedling root mass. Silenced <i>TaCKX2</i> T<sub>2</sub> lines with expression of <i>TaCKX2.2.1</i> and <i>TaCKX2.2.2</i> decreased by 33% and 30%, respectively, had significantly higher chlorophyll content in flag leaves. <i>TaCKX</i> GFM expression, phytohormone metabolism and phenotype were additionally modified by <i>Agrobacterium</i>-mediated transformation. Two novel phytohormones, phenylacetic acid (PAA) and topolins, lack of gibberellic acid (GA) and changed phytohormone contents in the 7 days after pollination (DAP) spikes of the awned-spike cultivar compared to a previously tested, awnless one, were detected. We documented that major mechanisms of coregulation of the expression of <i>TaCKX</i> GFMs were similar in different spring wheat cultivars, but, depending on content and composition of phytohormones, regulation of yield-related traits was variously impacted. |
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| ISSN: | 1661-6596 1422-0067 |