scholarly journals Cadmium adsorption in leaf cell walls prevents redistribution to silique in Arabidopsis thaliana ecotypes Jm-1 and Kyo-0

Author(s):  
Yan Xiao ◽  
Dong Liu ◽  
Li Li ◽  
Zhenhua Zhang ◽  
Jin-Song Luo
2021 ◽  
Author(s):  
Yan Xiao ◽  
Dong Liu ◽  
Li Li ◽  
Zhenhua Zhang ◽  
Jin-Song Luo

Abstract Background: Along with the rapid progress of industrialization and urbanization in the world, soil Cd pollution has become an increasingly serious problem. Phytoremediation has been widely used to mitigate heavy metal pollution in soils; however, it is difficult to reduce the Cd content in the grains of food crops using Cd pollution remediation techniques. Results: Here, we found that the Cd concentrations in the leaves, stems, and siliques of Arabidopsis thaliana (A. thaliana) ecotype Jm-1 were higher than in the ecotype Kyo-0. The Cd concentrations in the cell walls (CW) of the leaves were lower in Jm-1 than in Kyo-0, while the concentrations in the CW of the stem and silique were significantly higher in Jm-1 than in Kyo-0. The Cyclohexane Diamine Tetraacetic Acid (CDTA)-pectin and hemicellulose in Kyo-0 had higher Cd concentrations than those of Jm-1. The pectin methylesterase (PME) activity was higher in Kyo-0 than in Jm-1, and the expression levels of PME1, PME2, PME12, and PME25 were upregulated in Kyo-0 after Cd treatment. In addition, no significant differences in the Cd concentrations were found in the xylem of the two ecotypes, while the Cd concentration in the phloem was significantly higher in Jm-1 than in Kyo-0. The expression of iron transport-related genes showed that only YSL3 and ZIP11 had significant differences between the two ecotypes after Cd treatment, and the expression of the vacuolar Cd compartment-related genes that are responsible for transferring Cd from the cytoplasm to the vacuole showed that only CAX1 expression was significantly higher in Kyo-0 than in Jm-1. Conclusions: Kyo-0 accumulated less Cd than Jm-1 in the silique, which may be because (1) the activity of PME that is mainly regulated by PME1, PME2, PME12, and PME25 was higher in Kyo-0 leaves, leading to more Cd chelation in the pectin of the CWs, and (2) the expression of YSL3 was induced to regulate the transport of Cd in the phloem, thus reducing the transport of Cd to the silique. This study would benefit future research and agricultural practices.


Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 249
Author(s):  
Weimiao Liu ◽  
Liai Xu ◽  
Hui Lin ◽  
Jiashu Cao

The growth of plant cells is inseparable from relaxation and expansion of cell walls. Expansins are a class of cell wall binding proteins, which play important roles in the relaxation of cell walls. Although there are many members in expansin gene family, the functions of most expansin genes in plant growth and development are still poorly understood. In this study, the functions of two expansin genes, AtEXPA4 and AtEXPB5 were characterized in Arabidopsis thaliana. AtEXPA4 and AtEXPB5 displayed consistent expression patterns in mature pollen grains and pollen tubes, but AtEXPA4 also showed a high expression level in primary roots. Two single mutants, atexpa4 and atexpb5, showed normal reproductive development, whereas atexpa4atexpb5 double mutant was defective in pollen tube growth. Moreover, AtEXPA4 overexpression enhanced primary root elongation, on the contrary, knocking out AtEXPA4 made the growth of primary root slower. Our results indicated that AtEXPA4 and AtEXPB5 were redundantly involved in pollen tube growth and AtEXPA4 was required for primary root elongation.


Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1103-1106 ◽  
Author(s):  
Ruben Vanholme ◽  
Igor Cesarino ◽  
Katarzyna Rataj ◽  
Yuguo Xiao ◽  
Lisa Sundin ◽  
...  

Lignin is a major component of plant secondary cell walls. Here we describe caffeoyl shikimate esterase (CSE) as an enzyme central to the lignin biosynthetic pathway. Arabidopsis thaliana cse mutants deposit less lignin than do wild-type plants, and the remaining lignin is enriched in p-hydroxyphenyl units. Phenolic metabolite profiling identified accumulation of the lignin pathway intermediate caffeoyl shikimate in cse mutants as compared to caffeoyl shikimate levels in the wild type, suggesting caffeoyl shikimate as a substrate for CSE. Accordingly, recombinant CSE hydrolyzed caffeoyl shikimate into caffeate. Associated with the changes in lignin, the conversion of cellulose to glucose in cse mutants increased up to fourfold as compared to that in the wild type upon saccharification without pretreatment. Collectively, these data necessitate the revision of currently accepted models of the lignin biosynthetic pathway.


2010 ◽  
Vol 27 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Hitomi Ichinose ◽  
Nobuyuki Nishikubo ◽  
Taku Demura ◽  
Satoshi Kaneko

2014 ◽  
Vol 70 (3) ◽  
pp. 187-198
Author(s):  
Ewa Kupidłowska

The ultrastructure and morphology of roots treated with coumarin and umbelliferone as well as the reversibility of the coumarins effects caused by exogenous GA, were studied in <em>Arabidopsis thaliana</em>. Both coumarins suppressed root elongation and appreciably stimulated radial expansion of epidermal and cortical cells in the upper part of the meristem and in the elongation zone. The gibberellic acid applied simultaneously with coumarins decreased their inhibitory effect on root elongation and reduced cells swelling.Microscopic observation showed intensive vacuolization of cells and abnormalities in the structure of the Golgi stacks and the nuclear envelope. The detection of active acid phosphatase in the cytosol of swollen cells indicated increased membrane permeability. Significant abnormalities of newly formed cell walls, e.g. the discontinuity of cellulose layer, uncorrect position of walls and the lack of their bonds with the mother cell wall suggest that coumarins affected the cytoskeleton.


Planta ◽  
2000 ◽  
Vol 211 (6) ◽  
pp. 807-815 ◽  
Author(s):  
Emma Weston ◽  
Keira Thorogood ◽  
Giovanna Vinti ◽  
Enrique López-Juez

1964 ◽  
Vol 19 (12) ◽  
pp. 1146-1149 ◽  
Author(s):  
Wolfgang Franke ◽  
Ulrich Heber

Leaves, which had been killed in liquid air, were freeze dried and then fractionated by a nonaqueous method. Two fractions were obtained, one consisting of chloroplasts and the other of cytoplasm, vacuolar constituents, cell walls and residual chloroplasts. Calculation of the intracellular distribution of ascorbic acid based on the analysis of the two fractions revealed that 40 to 50% of the total ascorbic acid content of the cells is located within the chloroplasts. Since chloroplasts occupy less than 10% of the total volume of the cells, this high figure is direct evidence of an unequal distribution of ascorbic acid within the leaf cell.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1715
Author(s):  
Eleftheria Roumeli ◽  
Leah Ginsberg ◽  
Robin McDonald ◽  
Giada Spigolon ◽  
Rodinde Hendrickx ◽  
...  

Individual plant cells are the building blocks for all plantae and artificially constructed plant biomaterials, like biocomposites. Secondary cell walls (SCWs) are a key component for mediating mechanical strength and stiffness in both living vascular plants and biocomposite materials. In this paper, we study the structure and biomechanics of cultured plant cells during the cellular developmental stages associated with SCW formation. We use a model culture system that induces transdifferentiation of Arabidopsis thaliana cells to xylem vessel elements, upon treatment with dexamethasone (DEX). We group the transdifferentiation process into three distinct stages, based on morphological observations of the cell walls. The first stage includes cells with only a primary cell wall (PCW), the second covers cells that have formed a SCW, and the third stage includes cells with a ruptured tonoplast and partially or fully degraded PCW. We adopt a multi-scale approach to study the mechanical properties of cells in these three stages. We perform large-scale indentations with a micro-compression system in three different osmotic conditions. Atomic force microscopy (AFM) nanoscale indentations in water allow us to isolate the cell wall response. We propose a spring-based model to deconvolve the competing stiffness contributions from turgor pressure, PCW, SCW and cytoplasm in the stiffness of differentiating cells. Prior to triggering differentiation, cells in hypotonic pressure conditions are significantly stiffer than cells in isotonic or hypertonic conditions, highlighting the dominant role of turgor pressure. Plasmolyzed cells with a SCW reach similar levels of stiffness as cells with maximum turgor pressure. The stiffness of the PCW in all of these conditions is lower than the stiffness of the fully-formed SCW. Our results provide the first experimental characterization of the mechanics of SCW formation at single cell level.


2007 ◽  
Vol 64 (3) ◽  
pp. 295-301 ◽  
Author(s):  
J. Enroth ◽  
M. Ji

A new species of Neckeraceae, Neckera serrulatifolia Enroth & M.Ji, is described from Xizang (Tibet), China. It belongs in an Asian group of relatively robust, distinctly stipitate species with an obtuse leaf apex, relatively long costa and strongly incrassate-porose leaf cell walls, but differs from the other species by the combination of strongly complanate and undulate branch leaves, long leaf decurrencies, and serrulate margins at leaf base and at midleaf. The sporophytes remain unknown.


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