College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, PR China.
College of Life Science, University of the Chinese Academy of Sciences, Beijing, 100049, PR China.
Plant Physiol Biochem. 2024 Nov;216:109199. doi: 10.1016/j.plaphy.2024.109199. Epub 2024 Oct 15.
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.
土壤重金属（HMs）污染已成为全球性的环境问题。植物修复通过植物从土壤中提取重金属，可以以环保的方式有效地大量减少土壤中的重金属污染。镉诱导蛋白 AS8（CIPAS8）存在于许多植物中，其表达受 HMs 诱导。在这项研究中，PeCIPAS8 和 SlCIPAS8 被转入 84K 杨树中，以研究它们对木本植物耐受和转运镉的影响。定位分析表明，两种 CIPAS8 蛋白在瞬时表达于烟草叶片表皮细胞时定位于质膜。与野生型 84K 杨树幼苗相比，过表达 PeCIPAS8 或 SlCIPAS8 的转基因杨树系表现出更高的 Cd 含量和更低的 Cd 耐受性。与 Cd 胁迫下的野生型 84K 杨树相比，过表达 PeCIPAS8 或 SlCIPAS8 的转基因杨树系在营养阶段积累了更多的 Cd 在根、茎和叶中，但株高差异不显著。与野生型相比，CIPAS8 增加了转基因杨树根系的 Cd 流入率，并影响了其他金属转运蛋白的转录水平。这些发现表明 CIPAS8 增加了 Cd 流入植物组织的通量，并证明了植物对 Cd 的中度敏感性。因此，CIPAS8 是一种流入转运体，有可能增加在 HM 污染土壤中生长的木本植物对有毒 HMs 的吸收。
