Autophagy is one of the most common protective mechanisms during plant stress response. We studied the effect of exogenous Cd on autophagy in celery, by using transcriptome sequencing technique to analyze the differentially expressed genes under different Cd concentrations (0, 2, 4 and 8 mg/L). Eight differentially expressed autophagy-related genes were screened and identified by qRT-PCR. Cd had obvious toxic effect on celery, in a dose-dependent manner. Eight differentially expressed autophagy-related genes were screened, among which ATG8a, ATG8f, ATG13, AMPK-1 and AMPK-2 were up-regulated, whereas ATG12, VPS30 and VPS34 were first up-regulated and then decreased. The up-regulated expression of differential genes may resist Cd toxicity by increasing autophagosome structures; however, 8 mg/L Cd exceeded the autophagosome tolerance limit of celery, resulting in decreased expression of multiple autophagy-related genes. The above results can provide help for subsequent functional study of autophagy-related genes, and provide a reference for further exploring the tolerance mechanism of celery to Cd toxicity.
细胞自噬是植物逆境应答过程中最常见的保护机制之一。动物中，自噬相关基因抵御镉 (Cd) 毒害的功能研究较清楚，但植物却知之甚少。文中以芹菜品种‘皇后’为试材，采用外源Cd (终浓度为0、2、4、8 mg/L) 添加营养液水培处理，利用转录组测序 (RNA-seq) 技术筛选细胞自噬相关差异基因并进行qRT-PCR 验证。结果表明Cd 胁迫对芹菜植株产生了明显的毒害作用，并与浓度间产生了量效关系。在筛选的8 个差异表达的自噬相关基因中，ATG8a、ATG8f、ATG13、AMPK-1、AMPK-2 基因随Cd 浓度升高表达上调，ATG12、VPS30 和VPS34 则先上调后下降，说明自噬相关基因可能通过表达上调增加了自噬小体结构以抵御Cd 毒性作用；而高浓度Cd (8 mg/L)可能超出芹菜的耐受范围，导致多个自噬基因又出现表达下调趋势。以上结果有助于后期自噬相关基因的功能研究，为进一步探讨芹菜对Cd 胁迫的耐性机制提供参考依据。.
Keywords: Cd stress; autophagy-related gene; celery (Apiumgraveolens L.); screen; transcriptome.