AUTHOR=Kuang Xueshao , Wang Wumin , Hu Jiayao , Liu Wensheng , Zeng Wenbin 

TITLE=Subcellular distribution and chemical forms of manganese in Daucus carota in relation to its tolerance

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.947882

DOI=10.3389/fpls.2022.947882

ISSN=1664-462X

ABSTRACT=<p><italic>Daucus carota</italic> is a biennial herb of the Umbelliferae family, which is a candidate plant for the phytoremediation of Mn pollution. To reveal the mechanism of this plant to adapt to Mn stress, plant growth, anatomical structure, Mn accumulation characteristic, Mn subcellular distribution, and chemical forms of <italic>D. carota</italic> under six Mn<sup>2+</sup> concentrations by pot culture experiments were studied. The results showed that with the rising Mn concentrations, the total dry weight and leaf area of <italic>D. carota</italic> increased firstly and then decreased, while the specific leaf area increased. The thickness of the main vein, upper epidermis, and lower epidermis; the thickness of the palisade tissue; and the thickness of the spongy tissue of the leaves increased firstly and then decreased. The Mn content in the aboveground and underground parts of <italic>D. carota</italic> increased, and the values of the bioconcentration factor (BCF) and translocation factor (TF) were higher than 1. The Mn existing in the cell wall and soluble components accounted for the largest proportion, and the proportion of Mn in the cell wall increased with increasing concentrations of Mn. In addition, Mn mainly existed in ethanol extraction state, deionized water extraction state, and sodium chloride extraction state. The results showed that <italic>D. carota</italic> could alleviate the damage caused by high manganese concentration by storing most of manganese in the cell wall and vacuole and existing in the form of low-activity state.</p>