title: Cell wall polysaccharides are involved in P-deficiency-induced Cd exclusion in Arabidopsis thaliana.
abstract: The physiological and molecular mechanisms leading to the competitive interactions between phosphorus (P) and metal elements are a matter of debate. In this study, we found that P deficiency can alleviate cadmium (Cd) toxicity in Arabidopsis thaliana (Col-0). Under P deficiency (-P), less Cd was accumulated in the plants and the root cell walls, indicating the operation of a P-deficiency-induced Cd exclusion mechanism. However, organic acid efflux was similar under -P+Cd and +Cd treatments, suggesting that organic acid efflux is not responsible for the Cd exclusion. Interestingly, P deficiency significantly decreased cell wall polysaccharides (pectin and hemicellulose) contents and pectin methylesterase activity, and decreased the Cd retained by the extracted root cell wall. Therefore, we conclude that the modification of cell wall composition is responsible for the Cd exclusion of the root under P deficiency.
authors.affiliation: Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, Zhejiang University, Hangzhou 310058, China.
authors.forename: Xiao Fang
authors.initials: XF
authors.lastname: Zhu
authors.forename: Gui Jie
authors.initials: GJ
authors.lastname: Lei
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Gui Xin
authors.initials: GX
authors.lastname: Li
authors.forename: Shao Jian
authors.initials: SJ
authors.lastname: Zheng
mesh_terms: D017360:Arabidopsis / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D002104:Cadmium / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D002265:Carboxylic Ester Hydrolases / Q000187:drug effects / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D019343:Citric Acid / Q000032:analysis / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D010368:Pectins / Q000032:analysis / Q000378:metabolism; D010758:Phosphorus / Q000172:deficiency*; D053147:Plant Exudates / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis / Q000378:metabolism*; D036226:Seedlings / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D014574:Uronic Acids / Q000032:analysis / Q000378:metabolism
chemical_list: D053147:Plant Exudates; D011134:Polysaccharides; D014574:Uronic Acids; D002104:Cadmium; D002734:Chlorophyll; D010758:Phosphorus; D019343:Citric Acid; C007916:hemicellulose; D010368:Pectins; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase