Mo Zhenghai, Feng Gang, Su Wenchuan, Liu Zhuangzhuang, Peng Fangren
College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.
Genes (Basel). 2018 Feb 5;9(2):71. doi: 10.3390/genes9020071.
Pecan (), as a popular nut tree, has been widely planted in China in recent years. Grafting is an important technique for its cultivation. For a successful grafting, graft union development generally involves the formation of callus and vascular bundles at the graft union. To explore the molecular mechanism of graft union development, we applied high throughput RNA sequencing to investigate the transcriptomic profiles of graft union at four timepoints (0 days, 8 days, 15 days, and 30 days) during the pecan grafting process. After de novo assembly, 83,693 unigenes were obtained, and 40,069 of them were annotated. A total of 12,180 differentially expressed genes were identified between by grafting. Genes involved in hormone signaling, cell proliferation, xylem differentiation, cell elongation, secondary cell wall deposition, programmed cell death, and reactive oxygen species (ROS) scavenging showed significant differential expression during the graft union developmental process. In addition, we found that the content of auxin, cytokinin, and gibberellin were accumulated at the graft unions during the grafting process. These results will aid in our understanding of successful grafting in the future.
山核桃（）作为一种广受欢迎的坚果类树木，近年来在中国已被广泛种植。嫁接是其栽培的一项重要技术。为实现成功嫁接，嫁接愈合发育通常涉及在嫁接处形成愈伤组织和维管束。为探究嫁接愈合发育的分子机制，我们应用高通量RNA测序技术来研究山核桃嫁接过程中四个时间点（0天、8天、15天和30天）嫁接处的转录组图谱。经过从头组装，获得了83,693个单基因，其中40,069个得到注释。通过嫁接共鉴定出12,180个差异表达基因。参与激素信号传导、细胞增殖、木质部分化、细胞伸长、次生细胞壁沉积、程序性细胞死亡和活性氧（ROS）清除的基因在嫁接愈合发育过程中表现出显著差异表达。此外，我们发现生长素、细胞分裂素和赤霉素的含量在嫁接过程中在嫁接处积累。这些结果将有助于我们未来对成功嫁接的理解。
