What the study found
INDETERMINATE DOMAIN 5 (IDD5) in wheat and SEMI-DWARF 3 (SDW3) in barley were identified as positive regulators of stem and leaf expansion. The study found that both proteins physically interact with DELLA proteins and act downstream of them in gibberellin-mediated growth responses.
Why the authors say this matters
The authors say understanding how DELLA proteins regulate growth and development is important for refining breeding strategies. They also note that DELLA mutations have already been used to improve crop performance, but some widely used wheat alleles reduce early vigor and nitrogen use efficiency.
What the researchers tested
The researchers studied DELLA proteins, which are GRAS-domain transcriptional regulators, and their interactions with other factors in wheat and barley. They examined IDD5 and SDW3, including their physical interaction with DELLA proteins, their effects on growth, and the consequences of loss-of-function mutations. They also assessed altered expression of gibberellin biosynthesis genes and field performance of idd5 lines.
What worked and what didn't
IDD5 and SDW3 were associated with positive regulation of stem and leaf expansion. Loss-of-function mutations in IDD5 and SDW3 produced a gibberellin-insensitive semi-dwarf phenotype comparable in height to the Rht-D1b Green Revolution allele. In field trials, idd5 lines had improved grain weight per spike but lower overall yield because of reduced spike number.
What to keep in mind
The abstract does not describe all experimental details or specify the full set of field conditions. The field result reported for idd5 lines shows both a positive trait and a yield penalty, and the summary provided does not include broader testing across environments.
Key points
- IDD5 in wheat and SDW3 in barley were identified as positive regulators of stem and leaf expansion.
- Both proteins physically interact with DELLA proteins and act downstream of them in gibberellin-mediated growth responses.
- Loss-of-function mutations in IDD5 and SDW3 caused a gibberellin-insensitive semi-dwarf phenotype comparable to Rht-D1b.
- In field trials, idd5 lines had improved grain weight per spike but lower overall yield because of reduced spike number.
Disclosure
- Research title:
- IDD5 and SDW3 link DELLA proteins to stem growth in cereals
- Authors:
- Patrycja Sokolowska, Matthias Jöst, Wolfram Buss, Brett Ford, Peter Michael Chandler, Wolfgang Spielmeyer, Andrew L. Phillips, Alison K. Huttly, Danuše Tarkowská, Rocío Alarcón‐Reverte, Suzanne J. Clark, Stephen Pearce, Peter Hedden, Stephen G. Thomas
- Institutions:
- Rothamsted Research, Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Czech Academy of Sciences, Institute of Experimental Botany
- Publication date:
- 2026-01-30
- OpenAlex record:
- View
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