Shenglin Wang Yao Xiao ^* Zihao Li ^* Tao Liu ^* Jiarui Cui ^* Bicong Li ^* Qianglong Zhu Sha Luo Nan Shan ^* Jingyu Sun ^* Yingjin Huang ^* Qinghong Zhou ^*

• Jiangxi Agricultural University, Nanchang, China

Taro (Colocasia esculenta (L.) Schott) is the fifth largest rhizome crop widely distributed in tropical and subtropical areas in the world. However, perennial propagation with virus-carrying corms can lead to cultivar degradation, yield decline, and quality deterioration. In this study, shoot apical meristems (SAMs) cut from taro corms were cultured and further treated with exogenous abscisic acid (ABA) and high concentrations of sucrose to induce micro-corms, the related candidate genes involved in micro-corm expansion were screened by transcriptome sequencing analysis. The results revealed that the SAM could grow into adventitious shoots on the medium 1 mg/L 6-benzylaminopurine (6-BA) + 0.3 mg/L 1-naphthaleneacetic acid (NAA), and reverse transcription-polymerase chain reaction (RT-PCR) detection indicated that dasheen mosaic virus (DsMV) had been successfully eliminated from the test-tube plantlets. Moreover, 8% sucrose or 3% sucrose + 5 μM ABA likewise induced taro corm formation, and genes related to cell division and the cell cycle, starch and sucrose metabolism pathways were significantly enriched during taro corm expansion. Furthermore, the cyclin-dependent kinases (CDK), cell cycle protein kinase subunit (CKS), cyclin B2 (CYCB2) genes, which are related to cell division and the cell cycle, were upregulated with ABA treatment on the 3 rd day. The sucrose synthase gene (SUS), β-amylase (BAM), glycogen branching enzyme (GBE), soluble starch synthase (SSS) genes, which are related to starch and sucrose metabolism, were upregulated on the 15 th day, indicating that a large number of cells divide during taro corm formation, whereas carbohydrates are synthesized during taro corm expansion.