Overexpression of <i>OsCASP1</i> Improves Calcium Tolerance in Rice
The Casparian strip domain protein 1 (<i>OsCASP1</i>) is necessary for the formation of the Casparian strip (CS) in the rice endodermis. It also controls Ca<sup>2+</sup> transport to the stele. Here, we demonstrated that <i>OsCASP1</i> overexpression enhanced Ca t...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-06-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/11/6002 |
| Summary: | The Casparian strip domain protein 1 (<i>OsCASP1</i>) is necessary for the formation of the Casparian strip (CS) in the rice endodermis. It also controls Ca<sup>2+</sup> transport to the stele. Here, we demonstrated that <i>OsCASP1</i> overexpression enhanced Ca tolerance in rice. Under normal conditions, <i>OsCASP1</i>-overexpressed lines showed similar concentrations of essential metals in the roots and shoots compared to the wild type, while under high Ca conditions, Ca in the roots, shoots, and xylem sap of the <i>OsCASP1</i>-overexpressed lines was significantly decreased. This did not apply to other essential metals. Ca-inhibited growth was significantly alleviated in the <i>OsCASP1</i>-overexpressed lines. Furthermore, <i>OsCASP1</i> overexpression resulted in earlier formation of both the CS and functional apoplastic barrier in the endodermis but did not induce ectopic CS formation in non-endodermal cell layers and affect suberin accumulation in the endodermis. These results indicate that the overexpression of <i>OsCASP1</i> promotes CS formation in endodermal cells and inhibits Ca<sup>2+</sup> transport by the apoplastic pathway, restricting Ca accumulation in the roots and shoots under high Ca conditions. Taken together, the results suggest that <i>OsCASP1</i> overexpression is an effective way to improve rice adaptation to high Ca environments. |
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| ISSN: | 1661-6596 1422-0067 |