Genome-scale transcriptional study of hybrid effects and regulatory divergence in an F1 hybrid Ruellia (Wild Petunias: Acanthaceae) and its parents

BMC Plant Biology

Research Article

Yongbin Zhuang¹  Erin A. Tripp¹ 

[1] Department of Ecology and Evolutionary Biology, University of Colorado, UCB 334, 80309, Boulder, CO, USA;Museum of Natural History, University of Colorado, UCB 350, 80309, Boulder, CO, USA;

关键词: Anthocyanin;    Complementation;    Transgressive;    Ruellia;    Hybrid effects;    RNA-Seq;    Flower color;    MYB transcript factors;   

DOI  :  10.1186/s12870-016-0962-6

 received in 2016-07-27, accepted in 2016-12-22,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundNew combinations of divergent genomes can give rise to novel genetic functions in resulting hybrid progeny. Such functions may yield opportunities for ecological divergence, contributing ultimately to reproductive isolation and evolutionary longevity of nascent hybrid lineages. In plants, the degree to which transgressive genotypes contribute to floral novelty remains a question of key interest. Here, we generated an F1 hybrid plant between the red-flowered Ruellia elegans and yellow flowered R. speciosa. RNA-seq technology was used to explore differential gene expression between the hybrid and its two parents, with emphasis on genetic elements involved in the production of floral anthocyanin pigments.ResultsThe hybrid was purple flowered and produced novel floral delphinidin pigments not manufactured by either parent. We found that nearly a fifth of all 86,475 unigenes expressed were unique to the hybrid. The majority of hybrid unigenes (80.97%) showed a pattern of complete dominance to one parent or the other although this ratio was uneven, suggesting asymmetrical influence of parental genomes on the progeny transcriptome. However, 8.87% of all transcripts within the hybrid were expressed at significantly higher or lower mean levels than observed for either parent. A total of 28 unigenes coding putatively for eight core enzymes in the anthocyanin pathway were recovered, along with three candidate MYBs involved in anthocyanin regulation.ConclusionOur results suggest that models of gene evolution that explain phenotypic novelty and hybrid establishment in plants may need to include transgressive effects. Additionally, our results lend insight into the potential for floral novelty that derives from unions of divergent genomes. These findings serve as a starting point to further investigate molecular mechanisms involved in flower color transitions in Ruellia.

【 授权许可】

CC BY   
© The Author(s). 2017