Transcription factor bHLH121 regulates root cortical aerenchyma formation in maize
Issued Date
2023-03-21
Resource Type
ISSN
00278424
eISSN
10916490
Scopus ID
2-s2.0-85150314762
Pubmed ID
36927156
Journal Title
Proceedings of the National Academy of Sciences of the United States of America
Volume
120
Issue
12
Rights Holder(s)
SCOPUS
Bibliographic Citation
Proceedings of the National Academy of Sciences of the United States of America Vol.120 No.12 (2023)
Suggested Citation
Schneider H.M., Lor V.S., Zhang X., Saengwilai P., Hanlon M.T., Klein S.P., Davis J.L., Borkar A.N., Depew C.L., Bennett M.J., Kaeppler S.M., Brown K.M., Bhosale R., Lynch J.P. Transcription factor bHLH121 regulates root cortical aerenchyma formation in maize. Proceedings of the National Academy of Sciences of the United States of America Vol.120 No.12 (2023). doi:10.1073/pnas.2219668120 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/82140
Title
Transcription factor bHLH121 regulates root cortical aerenchyma formation in maize
Other Contributor(s)
Abstract
Root anatomical phenotypes present a promising yet underexploited avenue to deliver major improvements in yield and climate resilience of crops by improving water and nutrient uptake. For instance, the formation of root cortical aerenchyma (RCA) significantly increases soil exploration and resource capture by reducing the metabolic costs of root tissue. A key bottleneck in studying such phenotypes has been the lack of robust high-throughput anatomical phenotyping platforms. We exploited a phenotyping approach based on laser ablation tomography, termed Anatomics, to quantify variation in RCA formation of 436 diverse maize lines in the field. Results revealed a significant and heritable variation for RCA formation. Genome-wide association studies identified a single-nucleotide polymorphism mapping to a root cortex-expressed gene-encoding transcription factor bHLH121. Functional studies identified that the bHLH121 Mu transposon mutant line and CRISPR/Cas9 loss-of-function mutant line showed reduced RCA formation, whereas an overexpression line exhibited significantly greater RCA formation when compared to the wild-type line. Characterization of these lines under suboptimal water and nitrogen availability in multiple soil environments revealed that bHLH121 is required for RCA formation developmentally as well as under studied abiotic stress. Overall functional validation of the bHLH121 gene’s importance in RCA formation provides a functional marker to select varieties with improved soil exploration and thus yield under suboptimal conditions.