Abstract
The spikelet is a unique structure of inflorescence in grasses that generates one to many flowers depending on its determinate or indeterminate meristem activity. The growth patterns and number of spikelets, furthermore, define inflorescence architecture and yield. Therefore, understanding the molecular mechanisms underlying spikelet development and evolution are attractive to both biologists and breeders. Based on the progress in rice and maize, along with increasing numbers of genetic mutants and genome sequences from other grass families, the regulatory networks underpinning spikelet development are becoming clearer. This is particularly evident for domesticated traits in agriculture. This review focuses on recent progress on spikelet initiation, and spikelet and floret fertility, by comparing results from Arabidopsis with that of rice, sorghum, maize, barley, wheat, Brachypodium distachyon, and Setaria viridis. This progress may benefit genetic engineering and molecular breeding to enhance grain yield.
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Abbreviations
- AM:
-
Axillary meristem
- AP2/ERF:
-
APETALA2/ETHYLENE RESPONSE FACTOR
- bHLH:
-
Basic helix–loop–helix
- BM:
-
Branch meristem
- BR:
-
Brassinosteroid
- CK:
-
Cytokinin
- FAC:
-
Florigen activation complex
- FM:
-
Flower meristem
- GA:
-
Gibberellic acid
- HD-Zip:
-
Homeodomain leucine zipper
- IM:
-
Inflorescence meristem
- LD:
-
Long day
- PS:
-
Pedicellate spikelet
- SAM:
-
Shoot apical meristem
- SD:
-
Short day
- SpM:
-
Spikelet meristem
- SS:
-
Sessile spikelet
- TCP:
-
Teosinte branched/Cycloidea/PCF
- TF:
-
Transcription factor
- SL:
-
Strigolactone
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Acknowledgements
The authors would like to thank supporting by the funds from National Natural Science Foundation of China (31671260, 31470397 and 91417311); and China Innovative Research Team, Ministry of Education and the Programme of Introducing Talents of Discipline to Universities (111 Project, B14016), and SMC Morningstar Young Scholarship of Shanghai Jiao Tong University to Z. Y. S. P. is funded by ARC FT and DP Grants (DP190101941; FT160100218), and by a Villum Investigator Grant (Project ID: 25915) and Novo Nordisk Laureate Grant (NNF19OC0056076).
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Yuan, Z., Persson, S. & Zhang, D. Molecular and genetic pathways for optimizing spikelet development and grain yield. aBIOTECH 1, 276–292 (2020). https://doi.org/10.1007/s42994-020-00026-x
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DOI: https://doi.org/10.1007/s42994-020-00026-x