Landscape Architecture, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China.
Industrial Crop Research Institute of Sichuan Academy of Agricultural Sciences, Qingbaijiang, 610300, Sichuan, China.
Sci Rep. 2017 Oct 31;7(1):14691. doi: 10.1038/s41598-017-14407-8.
To date, several species of Asteraceae have been considered as Cd-accumulators. However, little information on the Cd tolerance and associated mechanisms of Asteraceae species Cosmos bipinnatus, is known. Presently, several physiological indexes and transcriptome profiling under Cd stress were investigated. C. bipinnatus exhibited strong Cd tolerance and recommended as a Cd-accumulator, although the biomasses were reduced by Cd. Meanwhile, Cd stresses reduced Zn and Ca uptake, but increased Fe uptake. Subcellular distribution indicated that the vacuole sequestration in root mainly detoxified Cd under lower Cd stress. Whilst, cell wall binding and vacuole sequestration in root co-detoxified Cd under high Cd exposure. Meanwhile, 66,407 unigenes were assembled and 41,674 (62.75%) unigenes were annotated in at least one database. 2,658 DEGs including 1,292 up-regulated unigenes and 1,366 down-regulated unigenes were identified under 40 μmol/L Cd stress. Among of these DEGs, ZIPs, HMAs, NRAMPs and ABC transporters might participate in Cd uptake, translocation and accumulation. Many DEGs participating in several processes such as cell wall biosynthesis, GSH metabolism, TCA cycle and antioxidant system probably play critical roles in cell wall binding, vacuole sequestration and detoxification. These results provided a novel insight into the physiological and transcriptome response to Cd in C. bipinnatus seedlings.
迄今为止，已发现多种菊科植物被认为是 Cd 积累植物。然而，有关菊科植物天人菊（Cosmos bipinnatus）Cd 耐性及其相关机制的信息却知之甚少。目前，研究了 Cd 胁迫下几种生理指标和转录组谱。C. bipinnatus 表现出较强的 Cd 耐性，可作为 Cd 积累植物，尽管 Cd 会降低生物量。同时，Cd 胁迫会降低 Zn 和 Ca 的吸收，但会增加 Fe 的吸收。亚细胞分布表明，在较低 Cd 胁迫下，根中的液泡隔离主要起到 Cd 解毒作用。而在高 Cd 暴露下，根中的细胞壁结合和液泡隔离共同起到 Cd 解毒作用。同时，组装了 66407 条 unigenes，其中 41674 条（62.75%）unigenes在至少一个数据库中得到注释。在 40μmol/L Cd 胁迫下，鉴定到 2658 个 DEGs，包括 1292 个上调 unigenes和 1366 个下调 unigenes。这些 DEGs 中，ZIPs、HMAs、NRAMPs 和 ABC 转运蛋白可能参与 Cd 的摄取、转运和积累。许多参与细胞壁生物合成、GSH 代谢、三羧酸循环和抗氧化系统等多个过程的 DEGs 可能在细胞壁结合、液泡隔离和解毒中发挥关键作用。这些结果为 C. bipinnatus 幼苗对 Cd 的生理和转录组响应提供了新的见解。
