Cadmium-induced protein AS8: A protein to improve Cd accumulation and transport via Cd uptake in poplar

• Published in: Plant physiology and biochemistry 2024-11, Vol.216, p.109199, Article 109199
• Main Authors: Shan, Qinghua, Guan, Jing, Yang, Yahan, Chai, Tuanyao, Gong, Shufang, Wang, Jingang, Qiao, Kun
• Format: Article
• Language: English
• Subjects: Accumulation; Biodegradation, Environmental; Biological Transport; Cadmium; Cadmium - metabolism; CIPAS8; Gene Expression Regulation, Plant - drug effects; Plant extraction; Plant Leaves - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - metabolism; Plants, Genetically Modified - metabolism; Poplar; Populus - drug effects; Populus - genetics; Populus - metabolism; Soil Pollutants - metabolism; Translocation
• ISSN: 0981-9428; 1873-2690; 1873-2690
• DOI: 10.1016/j.plaphy.2024.109199

The pollution of soil with heavy metals (HMs) has become an environmental problem of global concern. Phytoremediation, whereby plants extract HMs from soil, can efficiently and substantially reduce HM pollution in soil in an environmentally friendly manner. Cadmium-induced protein AS8 (CIPAS8) is present in many plants and its expression is induced by HMs. In this study, PeCIPAS8 and SlCIPAS8 were transformed into 84K poplar to study their effects on tolerance to, and translocation of, cadmium (Cd) in woody plants. Localization analyses showed that two CIPAS8 proteins were localized at the plasma membrane when transiently expressed in tobacco leaf epidermal cells. Compared with wild-type 84K poplar seedlings, transgenic poplar lines overexpressing PeCIPAS8 or SlCIPAS8 showed increased Cd contents and decreased Cd tolerance. Transgenic poplar lines overexpressing PeCIPAS8 or SlCIPAS8 accumulated more Cd in the roots, stems, and leaves, but the plant height did not differ significantly, compared with wild-type 84K poplar under Cd stress during the vegetative stage. CIPAS8 increased the Cd influx rate of transgenic poplar roots compared with that of the wild type, and affected the transcription levels of other metal transporters. These findings show that CIPAS8 increases Cd flux into plant tissues and demonstrate moderate Cd sensitivity of the plant. Therefore, CIPAS8 is an influx transporter with the potential to increase the uptake of toxic HMs by woody plants growing in HM-contaminated soils. [Display omitted] •PeCIPAS8 and SlCIPAS8 are plasma membrane proteins.•CIPAS8-OE/X poplar showed increased Cd content and Cd hypersensitivity.•Compared with wild type, CIPAS8-OE/X accumulated more Cd in roots, stems, and leaves.•CIPAS8 may be Cd influx transporter for Cd removal in contaminated soil.