Duplication and Diversification of REPLUMLESS – A Case Study in the Papaveraceae

Abstract

There is a vast amount of fruit morphological diversity in terms of their texture, the number of carpels, if those carpels are fused or not and how fruits open to disperse the seeds. Arabidopsis thaliana, a model eudicot, has a dry bicarpellate silique, when the fruit matures, the two valves fall apart through the dehiscence zone leaving the seeds attached to the remaining medial tissue, called the replum. Proper replum development in A. thaliana is mediated by REPLUMLESS (RPL), a TALE Homeodomain protein. RPL represses the valve margin genetic program and the downstream dehiscence zone formation in the medial tissue of the siliques and RPL orthologs have conserved roles across the Brassicaceae eudicots. A RPL homolog, qSH1, has been studied in rice, a monocot, and plays a role in fruit shedding making it difficult to predict functional evolution of this gene lineage across angiosperms. Although RPL orthologs have been identified across all angiosperms, expression and functional analyses are scarce. In order to fill the phylogenetic gap between the Brassicaceae and monocots we have characterized the expression patterns of RPL homologs in two poppies with different fruit types, Bocconia frutescens with operculate valvate dehiscence and a persistent medial tissue, similar to a replum, and Papaver somniferum, a poppy with persistent medial tissue in between the multicarpellate gynoecia. We found that RPL homologs in Papaveraceae have broad expression patterns during plant development; in the shoot apical meristem, during flowering transition and in many floral organs, especially the carpels. These patterns are similar to those of RPL in A. thaliana. However, our results suggest that RPL does not have conserved roles in the maintenance of medial persistent tissues of fruits but may be involved with establishing the putative dehiscence zone in dry poppy fruits.

The Evolution of euAPETALA2 Genes in Vascular Plants: From Plesiomorphic Roles in Sporangia to Acquired Functions in Ovules and Fruits

“…It is remarkable that AP2-like copies in both A. fimbriata and B. frutescens are broadly expressed in the fruit walls (or the commissural ring), but always remain absent from the dehiscence zones, which are the regions through which the pericarp will break to release the seeds. Previous studies of RPL homologues in B. frutescens show mutually exclusive expression patterns with BofrAP2 copies, as BofrRPL is restricted to the dehiscence zone ( Zumajo-Cardona et al. 2018 ).…”

“…All flower and fruit developmental stages described here are based on previous descriptions for Bocconia frutescens ( Zumajo-Cardona et al. 2017 ; Zumajo-Cardona et al. 2018 ) and A. fimbriata ( Pabón-Mora et al.…”

An angiospermNLRatlas reveals thatNLRgene reduction is associated with ecological specialization and signal transduction component deletion

“…These sequences were used as BLASTp queries against the genomic protein sequences of all 63 species that had simultaneously lost TNL, NRG1, and SAG101 (E-value = 1e-10). Mint-Evolutionary-Genomics-Consortium, 2018; Song et al, 2017;Xue et al, 2021;Zumajo-Cardona et al, 2018). E) Numbers of species lacking TNL and/or various .…”

“…for its linguistic assistance and scientific consultation during the preparation of this manuscript. Mint-Evolutionary-Genomics-Consortium, 2018; Song et al, 2017;Xue et al, 2021;Zumajo-Cardona et al, 2018). E) Numbers of species lacking TNL and/or various lifestyles.…”

Insights into opium poppy (Papaver spp.) genetic diversity from genotyping-by-sequencing analysis

“…The loss of dispersal mechanisms, increases in seed or organ size, changes in plant stature and reduced seed dormancy are among traits associated with domestication in plants (Ross-Ibarra et al ., 2007; Chen et al ., 2015). The capsules of many Papaver species and related genera dehisce primarily by small apical pores near the top of the capsule, facilitating seed dispersal by wind (Carolan et al ., 2006; Zumajo-Cardona et al ., 2018). Consequently, it is assumed that poricidal capsules are associated with wild forms and genotypes that produce indehiscent capsules, which retain seed in the capsules to full maturity and harvest, were selected for during poppy domestication (Zohary et al ., 2012).…”