WUSCHEL-related homeobox4 (WOX4) plays important roles in vascular formation and adventitious root (AR) development. Here, we cloned the WOX4 from the AR of Larix kaempferi, whose cDNA is 1452 bp in length and encodes 483 amino acids. LkWOX4 is mainly expressed in the layer formation area of the stem at 10 days after cutting and its expression levels in the middles and ends of the ARs were higher than that in the AR tips. The fused protein LkWOX4-GFP localized in the nucleus. The heterologous overexpression of LkWOX4 in 84 K poplar significantly increased AR numbers and decreased AR lengths. In LkWOX4 plants, the endogenous jasmonic acid and abscisic acid contents significantly decreased in stems, while the auxin, jasmonic acid and abscisic acid contents significantly increased in ARs. RNA-Seq of those LkWOX4 overexpression poplar plants showed that the expression of plant hormone signaling genes (ARF2, ARF3, ARF7 and ARF18), rooting-related transcription factors (WOX5, LBD29 and SCR) and root development-related genes (CYCD3, GRF1 and TAA1) were affected. Moreover, we found that LkWOX4 interacts with LkPAT18, LkACBP6, and LkCIP7 using yeast two hybrid screening. Thus, we found LkWOX4 involves in the AR initiation and development, which might be regulated through the IAA, JA and ABA signaling pathways.

与WUSCHEL相关的homeobox4（WOX4）在血管形成和不定根（AR）发育中起重要作用。在这里，我们从落叶松落叶松的AR中克隆了WOX4，其cDNA的长度为1452 bp，编码483个氨基酸。LkWOX4主要表达于切割后第10天的茎的层形成区域，其在AR的中，末端的表达水平高于AR尖端。融合蛋白LkWOX4-GFP位于细胞核中。LKWOX4在84 K杨树中的异源过表达显着增加了AR数量并减少了AR长度。在LkWOX4中在植物中，茎中的内源性茉莉酸和脱落酸含量明显降低，而ARs中的生长素，茉莉酸和脱落酸含量显着增加。那些LkWOX4过表达的杨树植物的RNA-Seq显示植物激素信号基因（ARF2，ARF3，ARF7和ARF18），与生根相关的转录因子（WOX5，LBD29和SCR）和与根发育相关的基因（CYCD3，GRF1）的表达和TAA1）受到影响。此外，我们发现使用酵母两个杂交筛选，LkWOX4与LkPAT18，LkACBP6和LkCIP7相互作用。因此，我们发现LkWOX4参与了AR的启动和发育，这可能是通过IAA，JA和ABA信号通路调节的。