Location: Plant, Soil and Nutrition ResearchTitle: Fertility of pedicellate spikelets in sorghum is controlled by a jasmonic acid regulatory module
|GLADMAN, NICHOLAS - Cold Spring Harbor Laboratory|
|JIAO, YINPING - Cold Spring Harbor Laboratory|
|LEE, YOUNG KOUNG - Cold Spring Harbor Laboratory|
|ZHANG, LIFANG - Cold Spring Harbor Laboratory|
|REGULSKI, MICHAEL - Cold Spring Harbor Laboratory|
|DAMPANABOINA, LAVANYA - Texas Tech University|
Submitted to: Nature Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2019
Publication Date: 10/8/2019
Citation: Gladman, N.P., Jiao, Y., Lee, Y., Zhang, L., Chopra, R., Regulski, M., Burow, G.B., Hayes, C.M., Christensen, S.A., Dampanaboina, L., Chen, J., Burke, J.J., Ware, D., Xin, Z. 2019. Fertility of pedicellate spikelets in sorghum is controlled by a jasmonic acid regulatory module. Nature Plants. 20(19). https://doi.org/10.3390/ijms20194951.
Interpretive Summary: We were able to determine that a gene involved in properly regulating enzyme function was disabled during a crucial stage of Sorghum seed head (panicle) development. This mutation lead to an increase in flower fertility compared to non-mutated sorghum, increasing grain number per panicle by ~200-300%. This particular gene product plays a role in hormone production during a narrow time and spatial area within the developing panicle, and as such does not seem to negatively influence other agronomic traits of the plant outside of panicle development. The implications of this work could lead to greater overall grain yield using the same nutrient inputs.
Technical Abstract: Traits that influence yield in crops have always been sought out by breeders and producers. In sorghum, increasing grain number per panicle (GNP) is a key avenue for such agricultural improvement. Via an EMS mutagenesis screen, we culled a series of multiseeded (msd) mutants that result in full spikelet fertility. Through next-generation sequencing, multiple msd lines were identified as having mutations within the lipoxygenase (LOX) domain-containing gene MSD2, which plays a role in the jasmonic acid (JA) biosynthetic pathway. The msd2 phenotype can be rescued by exogenous JA treatment. The transcriptomic profile of msd2 is similar to that of msd1 and reveals that it is in the post-floral transition stage of developing panicles where key gene regulation is required for the multiseeded trait to emerge. MSD2 can be directly regulated by the TCP transcription factor MSD1, mutants in which has been previously shown to developmental transcriptomic profiles and manifest the multiseeded phenotype. These results strengthen the association of JA pathway with sorghum panicle development and spikelet fertility that has implications for increasing GNP and grain yield as well as advancing understanding of inflorescence development.