Improvement of Rice Agronomic Traits by Editing Type-B Response Regulators
Type-B response regulator proteins in rice contain a conserved receiver domain, followed by a GARP DNA binding domain and a longer C-terminus. Some type-B response regulators such as RR21, RR22 and RR23 are involved in the development of rice leaf, root, flower and trichome. In this study, to evalua...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-11-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/23/22/14165 |
| Summary: | Type-B response regulator proteins in rice contain a conserved receiver domain, followed by a GARP DNA binding domain and a longer C-terminus. Some type-B response regulators such as RR21, RR22 and RR23 are involved in the development of rice leaf, root, flower and trichome. In this study, to evaluate the application potential of type-B response regulators in rice genetic improvement, thirteen type-B response regulator genes in rice were respectively knocked out by using CRISPR/Cas9 genome editing technology. Two guide RNAs (gRNAs) were simultaneously expressed on a knockout vector to mutate one gene. T<sub>0</sub> transformed plants were used to screen the plants with deletion of large DNA fragments through PCR with specific primers. The mutants of CRISPR/Cas9 gene editing were detected by <i>Cas9</i> specific primer in the T<sub>1</sub> generation, and homozygous mutants without <i>Cas9</i> were screened, whose target regions were confirmed by sequencing. Mutant materials of 12 <i>OsRRs</i> were obtained, except for <i>RR24</i>. Preliminary phenotypic observation revealed variations of various important traits in different mutant materials, including plant height, tiller number, tillering angle, heading date, panicle length and yield. The <i>osrr30</i> mutant in the T<sub>2</sub> generation was then further examined. As a result, the heading date of the <i>osrr30</i> mutant was delayed by about 18 d, while the yield was increased by about 30%, and the chalkiness was significantly reduced compared with those of the wild-type under field high temperature stress. These results indicated that <i>osrr30</i> has great application value in rice breeding. Our findings suggest that it is feasible to perform genetic improvement of rice by editing the type-B response regulators. |
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| ISSN: | 1661-6596 1422-0067 |