Differences in meristem size and expression of branching genes are associated with variation in panicle phenotype in wild and domesticated African rice

Differences in meristem size and expression of branching genes are associated with variation in panicle phenotype in wild and domesticated African rice Ta K. N. auteur aut IRD Adam Hélène auteur aut IRD Staedler Y. M. auteur aut IRD Schonenberger J. auteur aut IRD Harrop T. auteur aut IRD Tregear James auteur aut IRD Do N. V. auteur aut IRD Gantet Pascal auteur aut IRD Ghesquière Alain auteur aut IRD Jouannic Stefan auteur aut IRD text journalArticle eng text/pdf reformatted digital access Background: The African rice Oryza glaberrima was domesticated from its wild relative Oryza barthii about 3000 years ago. During the domestication process, panicle complexity changed from a panicle with low complexity in O. barthii, to a highly branched panicle carrying more seeds in O. glaberrima. To understand the basis of this differential panicle development between the two species, we conducted morphological and molecular analyses of early panicle development. Results: Using X-ray tomography, we analyzed the morphological basis of early developmental stages of panicle development. We uncovered evidence for a wider rachis meristem in O. glaberrima than in O. barthii. At the molecular level, spatial and temporal expression profiles of orthologs of O. sativa genes related to meristem activity and meristem fate control were obtained using in situ hybridization and qRT-PCR. Despite highly conserved spatial expression patterns between O. glaberrima and O. barthii, differences in the expression levels of these early acting genes were detected. Conclusion: The higher complexity of the O. glaberrima panicle compared to that of its wild relative O. barthii is associated with a wider rachis meristem and a modification of expression of branching-related genes. Our study indicates that the expression of genes in the miR156/miR529/SPL and TAW1 pathways, along with that of their target genes, is altered from the unbranched stage of development. This suggests that differences in panicle complexity between the two African rice species result from early alterations to gene expression during reproductive development. specialized Panicle Tomography Branching Meristem fate African rice AFRIQUE 076 Evodevo 8 art. 2 [14 p.] 2017 2041-9139 https://www.documentation.ird.fr/hor/fdi:010069324 10.1186/s13227-017-0065-y 2041-9139 [F B010069324] https://www.documentation.ird.fr/hor/fdi:010069324 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-04/010069324.pdf IRD - Base Horizon / Pleins textes 2017-05-09 2023-07-11 fdi:010069324 fre