Du Xuemei, Fang Ting, Liu Yan, Huang Liying, Zang Maosen, Wang Guoying, Liu Yunjun, Fu Junjie
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
Front Plant Sci. 2019 Dec 20;10:1633. doi: 10.3389/fpls.2019.01633. eCollection 2019.
Maize transformation is highly based on the formation of embryonic callus, which is mainly derived from scutellum cells of the immature maize embryo. However, only a few genes involved in callus induction have been identified in maize. To reveal the potential genes involved in the callus induction of maize, we carried out a high-throughput RNA sequencing on embryos that were cultured for 0, 1, 2, 4, 6, and 8 days, respectively, on a medium containing or lacking 2,4-dichlorophenoxyacetic acid. In total, 7,525 genes were found to be induced by 2,4-dichlorophenoxyacetic acid and categorized into eight clusters, with clusters 2 and 3 showing an increasing trend related to signal transmission, signal transduction, iron ion binding, and heme binding. Among the induced genes, 659 transcription factors belong to 51 families. An AP2 transcription factors, , was dramatically and rapidly induced by auxin and further characterization showed that overexpression of can promote callus induction and proliferation in three inbred maize lines. Therefore, our comprehensive analyses provide some insight into the early molecular regulations during callus induction and are useful for further identification of the regulators governing callus formation.
玉米转化高度依赖于胚性愈伤组织的形成，胚性愈伤组织主要来源于未成熟玉米胚的盾片细胞。然而，在玉米中仅鉴定出少数几个参与愈伤组织诱导的基因。为了揭示参与玉米愈伤组织诱导的潜在基因，我们对分别在含有或缺乏2,4-二氯苯氧乙酸的培养基上培养0、1、2、4、6和8天的胚进行了高通量RNA测序。总共发现7525个基因被2,4-二氯苯氧乙酸诱导，并被分为八个簇，其中簇2和簇3显示出与信号传递、信号转导、铁离子结合和血红素结合相关的增加趋势。在诱导基因中，659个转录因子属于51个家族。一个AP2转录因子被生长素显著且快速地诱导，进一步的表征表明该转录因子的过表达能够促进三个玉米自交系中愈伤组织的诱导和增殖。因此，我们的综合分析为愈伤组织诱导过程中的早期分子调控提供了一些见解，有助于进一步鉴定调控愈伤组织形成的调节因子。
