Zhang Xiaoli, Xu Liang, Wang Yan, He Min, Xin Ruixian, Yang Zhihe, Chu Wenjing, Ma Yinbo, Chen Yinglong, Wang Lun, Liu Liwang
National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Sanya Institute, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, PR China.
College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, 225009, China.
Plant Physiol Biochem. 2025 Mar;220:109449. doi: 10.1016/j.plaphy.2024.109449. Epub 2024 Dec 24.
Radish is an important annual root vegetable crop, whose yield is largely dependent on taproot thickening and development. However, the regulatory network of WOXs-mediated taproot development remains poorly understood in radish. Herein, the RsWOX13 was classified in an ancient clade of the WOX gene family that harbors a conserved homeodomain. RT-qPCR analysis revealed that the RsWOX13 gene was highly expressed in radish roots, leaves and flowers. Interestingly, both the promoter activity and expression of the RsWOX13 gene were significantly induced by cytokinin treatment, particularly at 3h. RsWOX13 possessed a transcriptional activation property, that was localized in the nucleus in tobacco leaves. Moreover, overexpression of RsWOX13 resulted in increased plant weight and root width in Arabidopsis, while virus-induced silencing of RsWOX13 inhibited cell expansion and cambium cell activities in radish. Several genes involved in cell wall biogenesis, hormone signaling and sucrose metabolic pathways were differentially expressed in the pTY and RsWOX13-silenced radish plants. Further investigations demonstrated that RsWOX13 directly activated the transcription of RsARR9, RsSUS1a, RsEXPA9 and RsEXPA1 genes by binding to their promoters, indicating that it promoted taproot development by integrating cell division and expansion and sucrose metabolism pathways. These results would provide novel insight into the molecular mechanisms underlying taproot development and facilitate enhancing root yields through genetic engineering approaches in radish.
萝卜是一种重要的一年生根菜类作物，其产量在很大程度上依赖于主根的加粗和发育。然而，在萝卜中，WOXs介导的主根发育调控网络仍知之甚少。在此，RsWOX13被归类于WOX基因家族的一个古老分支，该分支含有一个保守的同源异型结构域。RT-qPCR分析表明，RsWOX13基因在萝卜的根、叶和花中高度表达。有趣的是，细胞分裂素处理显著诱导了RsWOX13基因的启动子活性和表达，尤其是在处理3小时时。RsWOX13具有转录激活特性，定位于烟草叶片的细胞核中。此外，RsWOX13在拟南芥中的过表达导致植株重量和根宽度增加，而RsWOX13的病毒诱导沉默抑制了萝卜中的细胞扩张和形成层细胞活性。参与细胞壁生物合成、激素信号传导和蔗糖代谢途径的几个基因在pTY和RsWOX13沉默的萝卜植株中差异表达。进一步的研究表明，RsWOX13通过与RsARR9、RsSUS1a、RsEXPA9和RsEXPA1基因的启动子结合直接激活它们的转录，表明它通过整合细胞分裂和扩张以及蔗糖代谢途径促进主根发育。这些结果将为深入了解主根发育的分子机制提供新的见解，并有助于通过基因工程方法提高萝卜的根产量。
