Polyploidy-related differential gene expression between diploid and synthesized allotriploid and allotetraploid hybrids of Populus.

Liqin, Guo; Jianguo, Zhang; Xiaoxia, Liu; Guodong, Rao

Polyploids generally show vegetative growth superiority, higher biological yield, and enhanced resistance compared with diploids, which is already an important strategy in plant breeding; however, the mechanism by which these polyploid characteristics are formed remains unclear. Here, we developed a poplar polyploidy system to compare the phenotype and gene expression differences among newly synthesized Populus allotriploids and allotetraploids and their full-sib diploids. Analysis of gene expression revealed 156 genes that were significantly differentially expressed between diploids and triploids, among which 87 and 69 were up- and downregulated, respectively. Meanwhile, 384 genes were differentially expressed between diploids and tetraploids, and there were 259 upregulated and 125 downregulated genes, respectively. Polyploids showed a bigger stomatal, and stomatal length and width increased with ploidy level, whereas relative stomatal density decreased, which may mainly attribute to the differently expression of mitogen-activated protein kinase gene, YODA, and five plant hormone-related genes (SAUR, MES17, IAR3, BAS1, ABCG25). Plant height, leaf area, and petiole length were also observed to be significantly superior in polyploids than diploids, and E3 ligase BIG BROTHER (BB) and growth-regulating factor (GRF10) were selected as candidate genes responsible for variations in organ size and leaf growth. These results provided a robust resource for investigating the function of genes associated with polyploid genotype differences. Meanwhile, our study suggests that the poplar polyploidy system with clear and complete genetic backgrounds may be used as a good model for studies in polyploidization advantage.

GENE expression; MITOGEN-activated protein kinases; PLANT genes; POPLARS; PLANT breeding; MITOGENS

Molecular Breeding, 2019, Vol 39, Issue 5, pN.PAG

1380-3743

Academic Journal

10.1007/s11032-019-0975-6