Li Meng, Hou Lu, Zhang Chenxing, Yang Weicong, Liu Xinru, Zhao Hanqing, Pang Xiaoming, Li Yingyue
National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
Front Plant Sci. 2022 Feb 4;13:829765. doi: 10.3389/fpls.2022.829765. eCollection 2022.
The effects of whole-genome duplication span multiple levels. Previous study reported that the autotetraploid sour jujube exhibited superior drought tolerance than diploid. However, the difference in water transport system between diploids and autotetraploids and its mechanism remain unclear. Here, we found the number of xylem vessels and parenchyma cells in autotetraploid sour jujube increased to nearly twice that of diploid sour jujube, which may be closely related to the differences in xylem vessel differentiation-related ZjVND7 targets between the two ploidy types. Although the five enriched binding motifs are different, the most reliable motif in both diploid and autotetraploid sour jujube was CTTNAAG. Additionally, ZjVND7 targeted 236 and 321 genes in diploids and autotetraploids, respectively. More identified targeted genes of ZjVND7 were annotated to xylem development, secondary wall synthesis, cell death, cell division, and DNA endoreplication in autotetraploids than in diploids. SMR1 plays distinct roles in both proliferating and differentiated cells. Under drought stress, the binding signal of ZjVND7 to was stronger in autotetraploids than in diploids, and the fold-changes in the expression of and were larger in the autotetraploids than in the diploids. These results suggested that the targeted regulation of ZjVND7 on may play valuable roles in autotetraploids in the response to drought stress. We hypothesized that the binding of ZjVND7 to might play a role in cell division and transdifferentiation from parenchyma cells to vessels in the xylem. This regulation could prolong the cell cycle and regulate endoreplication in response to drought stress and abscisic acid, which may be stronger in polyploids.
全基因组复制的影响涉及多个层面。先前的研究报道，同源四倍体酸枣比二倍体表现出更强的耐旱性。然而，二倍体和同源四倍体之间水分运输系统的差异及其机制仍不清楚。在此，我们发现同源四倍体酸枣木质部导管和薄壁细胞的数量增加到二倍体酸枣的近两倍，这可能与两种倍性类型之间木质部导管分化相关的ZjVND7靶标的差异密切相关。尽管五个富集的结合基序不同，但二倍体和同源四倍体酸枣中最可靠的基序都是CTTNAAG。此外，ZjVND7在二倍体和同源四倍体中分别靶向236个和321个基因。与二倍体相比，同源四倍体中更多已鉴定的ZjVND7靶向基因被注释到木质部发育、次生壁合成、细胞死亡、细胞分裂和DNA内复制。SMR1在增殖细胞和分化细胞中发挥不同作用。在干旱胁迫下，ZjVND7与……的结合信号在同源四倍体中比在二倍体中更强，并且……和……表达的倍数变化在同源四倍体中比在二倍体中更大。这些结果表明，ZjVND7对……的靶向调控可能在同源四倍体应对干旱胁迫中发挥重要作用。我们推测，ZjVND7与……的结合可能在细胞分裂以及木质部中薄壁细胞向导管的转分化中起作用。这种调控可以延长细胞周期并响应干旱胁迫和脱落酸调节内复制，这在多倍体中可能更强。
