PtrARF2.1 Is Involved in Regulation of Leaf Development and Lignin Biosynthesis in Poplar Trees
PtrARF2.1 Is Involved in Regulation of Leaf Development and Lignin Biosynthesis in Poplar Trees
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PtrARF2.1 参与杨树叶片发育和木质素生物合成的调控
DOI：
10.3390/ijms20174141
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发表时间：
2019-09-01
影响因子：
5.6
通讯作者：
Luo, Keming
中科院分区：
文献类型：
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作者：
Fu, Yongyao;Win, Papa;Luo, Keming
生长素反应因子（ARF）是植物生长素反应基因表达的重要调节因子。在杨树基因组中，共鉴定出39个ARF成员，但其详细功能尚不清楚。本研究从大果杨中分离到6个白杨生长素反应因子2（PtrARF 2）成员。表达模式分析表明，与其他PtrARF 2基因相比，PtrARF 2.1在叶组织中高表达，并被外源生长素处理显著抑制。PtrARF2.1是一种位于核内的蛋白质，没有转录激活活性。在杨树中通过RNA干扰（RNAi）敲低PtrARF2.1导致植株矮小、改变叶片形状和减小叶片大小，而与野生型相比，过表达PtrARF2.1导致植株高度轻微降低和相似的叶片表型。此外，组织学染色分析显示，异位沉积的木质素在叶脉和叶柄的PtrARF2.1-RNAi线。RNA-Seq分析结果表明，在PtrARF 2. 1-RNAi叶片中共鉴定出NAM、ATAF、CUC（NAC）、v-myb禽成髓细胞瘤病毒癌基因同源物（MYB）、乙烯反应因子（ERF）和碱性螺旋-环-螺旋（bHLH）等12个转录因子家族的74个差异表达基因（DEG），另外24个DEG与木质素生物合成途径相关。PtrARF2.1基因在杨树叶片发育中起着重要的调控作用，并影响着杨树木质素的生物合成。
Auxin response factors (ARFs) are important regulators modulating the expression of auxin-responsive genes in various biological processes in plants. In the Populus genome, a total of 39 ARF members have been identified, but their detailed functions are still unclear. In this study, six poplar auxin response factor 2 (PtrARF2) members were isolated from P. trichocarpa. Expression pattern analysis showed that PtrARF2.1 is highly expressed in leaf tissues compared with other PtrARF2 genes and significantly repressed by exogenous auxin treatment. PtrARF2.1 is a nuclear-localized protein without transcriptional activation activity. Knockdown of PtrARF2.1 by RNA interference (RNAi) in poplars led to the dwarf plant, altered leaf shape, and reduced size of the leaf blade, while overexpression of PtrARF2.1 resulted in a slight reduction in plant height and the similar leaf phenotype in contrast to the wildtype. Furthermore, histological staining analysis revealed an ectopic deposition of lignin in leaf veins and petioles of PtrARF2.1-RNAi lines. RNA-Seq analysis showed that 74 differential expression genes (DEGs) belonging to 12 transcription factor families, such as NAM, ATAF and CUC (NAC), v-myb avian myeloblastosis viral oncogene homolog (MYB), ethylene response factors (ERF) and basic helix–loop–helix (bHLH), were identified in PtrARF2.1-RNAi leaves and other 24 DEGs were associated with the lignin biosynthetic pathway. Altogether, the data indicate that PtrARF2.1 plays an important role in regulating leaf development and influences the lignin biosynthesis in poplars.