Global gene expression defines faded whorl specification of double flower domestication in Camellia

Abstract

Double flowers in cultivated camellias are divergent in floral patterns which present a rich resource for demonstrating molecular modifications influenced by the human demands. Despite the key principle of ABCE model in whorl specification, the underlying mechanism of fine-tuning double flower formation remains largely unclear. Here a comprehensive comparative transcriptomics interrogation of gene expression among floral organs of wild type and “formal double” and “anemone double” is presented. Through a combination of transcriptome, small RNA and “degradome” sequencing, we studied the regulatory gene expression network underlying the double flower formation. We obtained the differentially expressed genes between whorls in wild and cultivated Camellia. We showed that the formation of double flowers tends to demolish gene expression canalization of key functions; the faded whorl specification mechanism was fundamental under the diverse patterns of double flowers. Furthermore, we identified conserved miRNA-targets regulations in the control of double flowers, and we found that miR172-AP2, miR156-SPLs were critical regulatory nodes contributing to the diversity of double flower forms. This work highlights the hierarchical patterning of global gene expression in floral development, and supports the roles of “faded ABC model” mechanism and miRNA-targets regulations underlying the double flower domestication.

Analysis of microRNA reveals cleistogamous and chasmogamous floret divergence in dimorphic plant

“…songorica . In this study, the size of small RNAs is from 21 nt to 24 nt which is consistent with previous reports, such as Petunia axillaris flower buds study 24 , and Camellia floral organs study 35 , etc. Here, all the potential target genes were classified based on GO, KEGG and COG annotations which provided basal information for further studies on flowering-associated miRNAs in C .…”

Screening and identification of miRNAs related to sexual differentiation of strobili in Ginkgo biloba by integration analysis of small RNA, mRNA, and degradome sequencing

“…The complex mechanism of Ascochyta blight resistance in chickpea were analyzed by means of multi-group sequencing combination [37]. In Camellia, miR172-AP2 and miR156-SPLs regulatory pairs were identi ed as key regulatory nodes to promote the diversity of double ower forms by the multi-group analysis [38]. In this study, three high-throughput approaches, namely, transcriptomics, small RNA and degradome sequencings were used to elucidate the mechanisms of sexual differentiation in G. biloba.…”

Molecular Cloning and Expression Analysis of C Function Gene <i>CjPLE</i> in Double Flower Varieties of <i>Camellia japonica</i>

“…Through the local BLAST comparison, a full length of 1 019 bp gene numbered c56140.graph_c0, homologous with PLE\, was discovered in transcriptome data of Camellia japonica bud (Li et al, 2017), of which the open reading frame (ORF) was 738 bp and encoded a total of 245 amino acids. The 5' non-coding region was 107 bp and 3' non-coding region was 174 bp.…”