National Engineering Research Center of Tree Breeding and Ecological Remediation, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing 100083, China.
Int J Mol Sci. 2022 Aug 28;23(17):9762. doi: 10.3390/ijms23179762.
Breeding for dwarfism is an important approach to improve lodging resistance. Here, we performed comparative analysis of the phenotype, transcriptome, and hormone contents between diploids and tetraploids of poplar 84K ( × ). Compared with diploids, the indole-3-acetic acid (IAA) and gibberellin (GA) contents were increased, whereas the jasmonic acid (JA) and abscisic acid (ABA) contents were decreased in tetraploids. RNA-sequencing revealed that differentially expressed genes (DEGs) in leaves of tetraploids were mainly involved in plant hormone pathways. Most DEGs associated with IAA and GA promotion of plant growth and development were downregulated, whereas most DEGs associated with ABA and JA promotion of plant senescence were upregulated. Weighted gene co-expression network analysis indicated that certain transcription factors may be involved in the regulation of genes involved in plant hormone pathways. Thus, the altered expression of some genes in the plant hormone pathways may lead to a reduction in IAA and GA contents, as well as an elevation in ABA and JA contents, resulting in the dwarfing of tetraploids. The results show that polyploidization is a complex biological process affected by multiple plant hormone signals, and it provides a foundation for further exploration of the mechanism of tetraploids dwarfing in forest trees.
培育矮化品种是提高抗倒伏性的重要途径。在这里，我们对杨树 84K（ × ）的二倍体和四倍体进行了表型、转录组和激素含量的比较分析。与二倍体相比，四倍体中的吲哚-3-乙酸（IAA）和赤霉素（GA）含量增加，而茉莉酸（JA）和脱落酸（ABA）含量降低。RNA-seq 分析表明，四倍体叶片中的差异表达基因（DEGs）主要参与植物激素途径。与 IAA 和 GA 促进植物生长和发育相关的大多数 DEGs 下调，而与 ABA 和 JA 促进植物衰老相关的大多数 DEGs 上调。加权基因共表达网络分析表明，某些转录因子可能参与了参与植物激素途径的基因的调控。因此，植物激素途径中某些基因的表达改变可能导致 IAA 和 GA 含量降低，ABA 和 JA 含量升高，从而导致四倍体矮化。研究结果表明，多倍化是一个受多种植物激素信号影响的复杂生物学过程，为进一步探索树木四倍体矮化的机制提供了基础。
