title: Physiological and biochemical responses of Ulva prolifera and Ulva linza to cadmium stress.
abstract: Responses of Ulva prolifera and Ulva linza to Cd(2+) stress were studied. We found that the relative growth rate (RGR), Fv/Fm, and actual photochemical efficiency of PSII (Yield) of two Ulvaspecies were decreased under Cd(2+) treatments, and these reductions were greater in U. prolifera than in U. linza. U. prolifera accumulated more cadmium than U. linza under Cd(2+) stress. While U. linza showed positive osmotic adjustment ability (OAA) at a wider Cd(2+) range than U. prolifera. U. linza had greater contents of N, P, Na(+), K(+), and amino acids than U. prolifera. A range of parameters (concentrations of cadmium, Ca(2+), N, P, K(+), Cl(-), free amino acids (FAAs), proline, organic acids and soluble protein, Fv/Fm, Yield, OAA, and K(+)/Na(+)) could be used to evaluate cadmium resistance in Ulva by correlation analysis. In accordance with the order of the absolute values of correlation coefficient, contents of Cd(2+) and K(+), Yield, proline content, Fv/Fm, FAA content, and OAA value of Ulva were more highly related to their adaptation to Cd(2+) than the other eight indices. Thus, U. linza has a better adaptation to Cd(2+) than U. prolifera, which was due mainly to higher nutrient content and stronger OAA and photosynthesis in U. linza.
authors.affiliation: College of Natural Resources and Environmental Science, Key Laboratory of Marine Biology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
authors.forename: He-ping
authors.initials: HP
authors.lastname: Jiang
authors.forename: Bing-bing
authors.initials: BB
authors.lastname: Gao
authors.forename: Wen-hui
authors.initials: WH
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Zhu
authors.forename: Chun-fang
authors.initials: CF
authors.lastname: Zheng
authors.forename: Qing-song
authors.initials: QS
authors.lastname: Zheng
authors.forename: Chang-hai
authors.initials: CH
authors.lastname: Wang
mesh_terms: D000222:Adaptation, Physiological; D000596:Amino Acids / Q000032:analysis; D002104:Cadmium / Q000737:chemistry; D019256:Cadmium Chloride / Q000494:pharmacology*; D002338:Carotenoids / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D009995:Osmosis; D010758:Phosphorus / Q000032:analysis; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000032:analysis* / Q000737:chemistry; D011188:Potassium / Q000032:analysis; D012964:Sodium / Q000032:analysis; D013045:Species Specificity; D013312:Stress, Physiological; D044445:Ulva / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*
chemical_list: D000596:Amino Acids; D045332:Photosystem II Protein Complex; D002104:Cadmium; D002734:Chlorophyll; D010758:Phosphorus; D002338:Carotenoids; D012964:Sodium; D019256:Cadmium Chloride; D009584:Nitrogen; D011188:Potassium