title: Improvement of cerium on photosynthesis of maize seedlings under a combination of potassium deficiency and salt stress.
abstract: Added Ce(3+) can partly substitute for Ca(2+) or Mg(2+) and improve photosynthesis under the deficiency of these elements, but very few studies focused on photosynthetic improvement in maize seedlings caused by K(+) deficiency, salt stress, especially a combination of K(+) deficiency and salt stress. In the present study, the effects of Ce(3+) on the photosynthesis of maize seedlings under the three different stresses were investigated. The results showed that added Ce(3+) under various stresses increased the ratios of free water/bound water and of K(+)/Na(+), the pigment contents, the values of Fv/Fm, Y(II), ETR(II), Y(NPQ), Qp, qL, NPQ, and qN of photosystem II (PSII), the values of Y(I) and ETR(I) of photosystem I (PSI) and the expression levels of LhcII cab1 and rbcL, and decreased the values of Y(NO) and Y(NA). This implied that added Ce(3+) depressed ion toxicity, photodamage of PSII, and acceptor side constraints of PSI, and enhanced adjustable energy dissipation, the responses of photochemistry, and carbon assimilation caused by K(+) deficiency, salt stress, and the combination of K(+) deficiency and salt stress. However, Ce(3+) mitigation of photosynthetic inhibition in maize seedlings caused by the combined stresses was greater than that of salt stress, and Ce(3+) mitigation under salt stress was greater than that under K(+) deficiency. In addition, the results also showed that Ce(3+) cannot improve photosynthesis and growth of maize seedlings under K(+) deficiency by substituting for K(+).
authors.affiliation: Medical College, Soochow University, Suzhou, People's Republic of China.
authors.forename: Chunxiang
authors.initials: C
authors.lastname: Qu
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.forename: Fugen
authors.initials: F
authors.lastname: Guo
authors.forename: Chenliang
authors.initials: C
authors.lastname: Hu
authors.forename: Yuguan
authors.initials: Y
authors.lastname: Ze
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Li
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Zhou
authors.forename: Fashui
authors.initials: F
authors.lastname: Hong
mesh_terms: D002563:Cerium / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D045342:Light-Harvesting Protein Complexes / Q000235:genetics; D055668:Photochemical Processes / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects*; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics; D036226:Seedlings / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism*; D013312:Stress, Physiological; D003313:Zea mays / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D045342:Light-Harvesting Protein Complexes; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D002563:Cerium; D012965:Sodium Chloride; C101625:RbcL protein, plastid; D012273:Ribulose-Bisphosphate Carboxylase; D011188:Potassium