Study on Gene Differential Expression in Tetraploid Populus Leaves

Abstract

Polyploids exhibit different phenotypes compared to those of diploids in plants, and the important role of polyploids in tree breeding has been widely recognized. The transcriptomes detected by RNA-seq in the Populus triploid by doubling the chromosomes of the female gamete, in the triploid by doubling the chromosomes of somatic cells and the diploid with the parent were compared to reveal the patterns of gene expression of tetraploid leaves and their influence on growth. The results showed that the high expression of GATA and PORA in tetraploid leaves was the reason for the higher chlorophyll content in the leaves than in diploid and triploid leaves. The 11-day-old tetraploid leaves began to enter the aging stage. Compared with that in the diploid, GRF was significantly upregulated, while the amylase genes were downregulated. Compared with those in the triploid, 3 STN7 genes that regulate photosynthetic genes and PGSIP genes which are related to starch synthesis, were significantly downregulated in the tetraploid, and the auxin receptor protein TIR1 was also significantly downregulated. In the tetraploid, auxin-regulating genes such as GH3 and AUX/IAA as well as genes involved in the regulation of leaf senescence, SAG genes and SRG genes were significantly up-regulated, resulting in a decrease in the auxin content. In senescent leaves, CHLD, CHLI1, and CHLM in the early stage of chlorophyll synthesis all began to downregulate their expressions, leading to the downregulation of LHC genes and a decrease in their photosynthetic efficiency, which led to the downregulation of carbon fixation-related genes such as SS genes, thus affecting carbon synthesis and fixation. This finally led to the slow growth of tetraploid plants. These data represent the transcriptome characteristics of tetraploid, and they can be used as a resource for further research on polyploids and provide a reference for further understanding of the function of polyploid vegetative growth-related genes.

Induced polyploidy deeply influences reproductive life cycles, related phytochemical features, and phytohormonal activities in blackberry species

“…Polyploid plants had higher levels of growth-stimulating phytohormones. In accordance with the results of this research, Zhang et al (2020) ascribed the growth advantages of polyploid Populus plants to enhanced biosynthesis rates of cytokinin, auxin, gibberellin, and photosynthetic capacity, which lead to greater carbon fixation and higher sugar/starch contents. Plant growth regulators and their related ratios varied dramatically during the blooming process in this study, revealing intricate hormonal connections.…”

Ploidy variation on gene differential expression in cowpea

“…Through gene ontology annotation analysis, it was found that differential genes were mainly enriched in metabolism and cell composition, and metabolism and cell composition mainly affected plant growth and metabolism, which was consistent with the results of morphological and physiological differences between diploid and tetraploid cowpea. It confirmed the results of previous studies on populus tetraploid that differential genes were mainly enriched in cell process and metabolic process (ZHANG et al, 2020). KEGG pathway analysis showed that the DEGs were significantly enriched in six pathways: flavonoid biosynthesis, degradation of other glycans, phenylpropane biosynthesis, starch sucrose metabolism, cutin, amber and wax biosynthesis, circadian rhythm plant pathway.…”

Modulation of defense genes and phenolic compounds in wild blueberry in response to Botrytis cinerea under field conditions

“…Although Vm and Va phenotypes had similar expression values, it is worth noting the difference in ploidy between the two groups. Polyploid species tend to have higher expression of genes during genome analysis [ 66 , 67 ]. Hence, coupled with its unique morphological features and late flower bud development, theoretically doubling the expression levels in the Vm phenotypes could show strong up-regulation of the various genes to possibly explain why Vm is less susceptible to pathogens.…”