State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China; College of Bioengineering and Biotechnology, Tianshui Normal University, Gansu 741000, China.
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
Gene. 2020 Oct 20;758:144942. doi: 10.1016/j.gene.2020.144942. Epub 2020 Jul 5.
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.
WOX4 在家系相关同源框 4 中发挥重要作用，参与血管形成和不定根（AR）发育。在这里，我们从日本落叶松的 AR 中克隆了 WOX4，其 cDNA 长 1452bp，编码 483 个氨基酸。LkWOX4 主要在切割后 10 天的茎层形成区表达，其在 AR 中部和末端的表达水平高于 AR 尖端。融合蛋白 LkWOX4-GFP 定位于细胞核中。在 84K 杨树中异源过表达 LkWOX4 显著增加了 AR 数量，降低了 AR 长度。在 LkWOX4 植株中，茎中的内源茉莉酸和脱落酸含量显著降低，而 AR 中的生长素、茉莉酸和脱落酸含量显著增加。这些 LkWOX4 过表达杨树植物的 RNA-Seq 显示，植物激素信号基因（ARF2、ARF3、ARF7 和 ARF18）、生根相关转录因子（WOX5、LBD29 和 SCR）和根发育相关基因（CYCD3、GRF1 和 TAA1）的表达受到影响。此外，我们发现 LkWOX4 通过酵母双杂交筛选与 LkPAT18、LkACBP6 和 LkCIP7 相互作用。因此，我们发现 LkWOX4 参与 AR 的起始和发育，可能通过 IAA、JA 和 ABA 信号通路进行调节。
