Maghrebi Moez, Baldoni Elena, Lucchini Giorgio, Vigani Gianpiero, Valè Giampiero, Sacchi Gian Attilio, Nocito Fabio Francesco
Dipartimento di Scienze Agrarie e Ambientali-Produzione, Territorio, Agroenergia (DISAA), Università degli Studi di Milano, 20133 Milano, Italy.
Istituto di Biologia e Biotecnologia Agraria (IBBA), Consiglio Nazionale delle Ricerche (CNR), 20133 Milano, Italy.
Plants (Basel). 2021 Apr 20;10(4):806. doi: 10.3390/plants10040806.
Two rice accessions, Capataz and Beirao, contrasting for cadmium (Cd) tolerance and root retention, were exposed to a broad range of Cd concentrations (0.01, 0.1, and 1 μM) and analyzed for their potential capacity to chelate, compartmentalize, and translocate Cd to gain information about the relative contribution of these processes in determining the different pathways of Cd distribution along the plants. In Capataz, Cd root retention increased with the external Cd concentration, while in Beirao it resulted independent of Cd availability and significantly higher than in Capataz at the lowest Cd concentrations analyzed. Analysis of thiol accumulation in the roots revealed that the different amounts of these compounds in Capataz and Beirao, as well as the expression levels of genes involved in phytochelatin biosynthesis and direct Cd sequestration into the vacuoles of the root cells, were not related to the capacity of the accessions to trap the metal into the roots. Interestingly, the relative transcript abundance of , a gene controlling root-to-shoot Cd/Zn translocation, was not influenced by Cd exposure in Capataz and progressively increased in Beirao with the external Cd concentration, suggesting that activity of the OsHMA2 transporter may differentially limit root-to-shoot Cd/Zn translocation in Capataz and Beirao.
两个水稻品种Capataz和Beirao在镉（Cd）耐受性和根部滞留方面存在差异，将它们暴露于广泛的Cd浓度（0.01、0.1和1μM）下，并分析它们螯合、区室化和转运Cd的潜在能力，以获取有关这些过程在确定Cd沿植物分布的不同途径中的相对贡献的信息。在Capataz中，Cd根部滞留量随外部Cd浓度增加而增加，而在Beirao中，其结果与Cd有效性无关，并且在分析的最低Cd浓度下显著高于Capataz。对根部硫醇积累的分析表明，Capataz和Beirao中这些化合物的不同含量，以及参与植物螯合肽生物合成和将Cd直接隔离到根细胞液泡中的基因的表达水平，与品种将金属捕获到根部的能力无关。有趣的是，控制根到地上部Cd/Zn转运的基因的相对转录丰度在Capataz中不受Cd暴露的影响，而在Beirao中随着外部Cd浓度的增加而逐渐增加，这表明OsHMA2转运蛋白的活性可能在Capataz和Beirao中对根到地上部Cd/Zn转运产生不同的限制。
