Molecular Mechanism of Vegetative Growth Advantage in Allotriploid Populus

Abstract

Allotriploid poplar has a prominent vegetative growth advantage that impacts dramatically on lumber yield. The growth regulation is complex which involves abundant genes, metabolic and signaling pathways, while the information about the functional control process is very little. We used high-throughput sequencing and physiological index measurement to obtain a global overview of differences between allotriploid and diploid Populus. The genes related to plant growth advantage show a higher expression compared to diploid, and most of them are revolved around hormones, photosynthesis and product accumulation. Thus, allotriploid Populus showed more efficient photosynthesis, carbon fixation, sucrose and starch synthesis, and metabolism as well as augmented biosynthesis of auxin, cytokinin, and gibberellin. These data enable the connection of metabolic processes, signaling pathways, and specific gene activity, which will underpin the development of network models to elucidate the process of triploid Populus advantage growth.

Comparative Proteomic Analysis of Leaves at Different Ages in Allotriploid Populus

“…Senescence is the final developmental step of a leaf, which is usually characterized by a decrease in chlorophyll content and photosynthesis [39]. The DAPs involved in photosynthesis displayed lower accumulation in FDR25 as compared to FDR10 (Figure 3c), consistent with the decrease of photosynthesis and chlorophyll reported by our previous study [25]. Additionally, the numbers of DAPs and significantly altered biological functional categories between FDR10 and FDR25 were the smallest among all comparisons, implying that FDR25 leaves were entering the early stages of aging (Figure 3c).…”

“…In this study, we utilized a label-free shotgun proteomics approach to perform a comprehensive proteomic profiling of leaves of different leaf-ages in Populus allotriploids, which were obtained through first-division restitution (FDR) induced by high-temperature exposure. Previous phenotype analysis has implied that leaves from the 5th (FDR5), 10th (FDR10), and 25th (FDR25) from stem apices represented young, mature, and initially aged leaves, respectively [25]. These leaves from these three positions were investigated.…”

Study on Gene Differential Expression in Tetraploid Populus Leaves

“…Chlorophyll synthesis, light capture, photosynthesis, carbon fixation, and sugar and starch synthesis and decomposition raised the expressions of related genes, made the endogenous hormone synthesis and signal transduction process more robust, and the miRNA expression showed no significant difference between the triploid and diploid. Moreover, the changes in growth-related gene expression are the molecular basis of the triploid growth advantage of Populus [19][20][21]. The high expressions of the WRKY transcription factor, cyclin CYCD, and genes related to the synthesis of auxin, cytokinin, and brassinolide made the triploid leaves large [22].…”

Tetraploidy Confers Superior in vitro Water-Stress Tolerance to the Fig Tree (Ficus carica) by Reinforcing Hormonal, Physiological, and Biochemical Defensive Systems

“…The significantly low percentage of ion leakage in tetraploid explants than their diploid control plants in the present study might be related to their superior adaptive strategies such as robust osmotic adjustment and cell detoxification systems, which lead to maintaining the cell membrane integrity and preventing its destruction (Wei et al, 2019). These augmented critical strategies resulting from chromosome doubling could also play a key role in preventing the degradation of photosynthetic pigments and plant cytokinins, which are essential for photosynthetic pigments biosynthesis (Du et al, 2020). Due to that, tetraploid explants had significantly greater chlorophyll and carotenoid contents under all water stress treatments.…”