Molecular cloning and characterization of a brassinosteriod biosynthesis-related gene PtoDWF4 from Populus tomentosa
Molecular cloning and characterization of a brassinosteriod biosynthesis-related gene PtoDWF4 from Populus tomentosa
复制标题
毛白杨油菜素甾醇生物合成相关基因PtoDWF4的分子克隆及表征
DOI：
10.1093/treephys/tpy027
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发表时间：
2018-09-01
期刊：
影响因子：
4
通讯作者：
Luo, Keming
中科院分区：
文献类型：
--
作者：
Shen, Yun;Li, Yongli;Luo, Keming
油菜素类固醇(BRs)作为类固醇激素在植物的生长发育中起着重要的作用。然而，关于BRs如何影响木本植物次生壁的生物合成，人们知之甚少。在本研究中，我们从毛白杨中克隆并鉴定了拟南芥DWF4的同源基因PtoDWF4，该基因编码细胞色素P450蛋白。QRT-PCR分析表明，PtoDWF4在茎中高表达，尤其在木质部中表达较高。过表达PtoDWF4(PtoDWF4-OE)促进了杨树的生长速度和生物量，增加了木质部的面积和细胞层。与野生型相比，转基因植株的株高和茎粗显著增加。相反，由CRISPR/Cas9产生的PtoDWF4(PtoDWF4-KO)突变导致转基因植物的生物量显著下降。进一步的研究表明，PtoDWF4的结构性表达上调了次生细胞壁(SCW)生物合成相关基因的表达，而敲除PtoDWF4则下调了这些基因的表达。细胞壁成分的定量分析表明，与野生型植株相比，PtoDWF4-OE系的细胞壁成分显着增加，而PtoDWF4-KO系的细胞壁成分减少。综上所述，我们的结果表明，PtoDWF4在促进杨树生长和提高生物量方面具有积极的作用。
Brassinosteroids (BRs) as steroid hormones play an important role in plant growth and development. However, little is known about how BRs affect secondary wall biosynthesis in woody plants. In this study, we cloned and characterized PtoDWF4, a homologus gene of Arabidopsis DWF4 encoding a cytochrome P450 protein, from Populus tomentosa. qRT-PCR analysis showed that PtoDWF4 was highly expressed in stems, especially in xylem. Overexpression of PtoDWF4 (PtoDWF4-OE) in poplar promoted growth rate and biomass yield, increased area and cell layers of xylem. Transgenic plants showed a significant increase in plant height and stem diameter compared with the wild type. In contrast, the CRISPR/Cas9-generated mutation of PtoDWF4 (PtoDWF4-KO) resulted in significantly decreased biomass production in transgenic plants. Further studies revealed that constitutive expression of PtoDWF4 up-regulated the expression of secondary cell wall (SCW) biosynthesis-related genes, whereas knock-out of PtoDWF4 down-regulated their expression. Quantitative analysis of cell wall components showed a significant increase in PtoDWF4-OE lines but a reduction in PtoDWF4-KO lines compared with wild-type plants. Taken together, our results indicate that PtoDWF4 plays a positive role in improving growth rate and elevating biomass production in poplar.