1. The Magnesium Transporter MGT10 Is Essential for Chloroplast Development and Photosynthesis in Arabidopsis thaliana 
Yi Sun, Runan Yang, Legong Li, Jirong Huang 
Molecular Plant 
Volume 10, Issue 12, Pages (December 2017)
DOI: /j.molp
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2. Figure 1
Loss-of-Function Mutations in MGT10 Lead to Multiple Defects in Chloroplast Development, Photosynthesis, and Mg2+ Content, Which Are Partially Rescued by Low Light.
(A) Phenotypes of 28-day-old WT, mgt10, and two independent lines for genetic complementation and amiMGT10. Bars, 1 cm.
(B) Cell-specific expression patterns of MGT10 in a cross-section of leaves from 28-day-old plants expressing the GUS reporter gene driven by the native promoter. The square shows a vein. Bars, 100 μm. Ep, epidermis; Sp, spongy mesophyll; Pa, palisade mesophyll; Bs, bundle sheath; Ph, phloem; Xy, xylem.
(C) Ultrastructure of chloroplasts in mesophyll cells adjacent to the leaf vascular bundle from leaves of 28-day-old WT and mgt10 plants. In mgt10, two representative types of chloroplasts are shown with longer grana stacks and/or more layers of the thylakoid membrane. Bars, 1 μm.
(D–F) Photosynthetic parameters analyzed with mature leaves cut from 28-day-old WT and mgt10 plants grown under normal light (NL, 100 μmol m−2 s−1). For high light (HL) treatment, the plants were illuminated with 600 μmol m−2 s−1 for 3 h before the leaves were sampled. (D) Fv/Fm, values are means ± SE (n = 9). **P < 0.01, Student's t-test. (E) NPQ, values are means ± SE (n = 4). (F) ms-DLE. The peak of the ms-DLE curve was used to calculate the values, shown as means ± SE (n = 10). **P < 0.01, Student's t-test.
(G) The yellow cotyledon phenotype of mgt10 was not rescued by Mg2+. Seedlings were grown on sucrose-free half MS media, in which the MgSO4 concentration was altered as indicated, under normal light for 11 days. All pictures are shown in the same scale. Bars, 1 mm.
(H and I) ICP-MAS analysis of mineral content. (H) Content of Mg, Ca, and Fe in leaves of 40-day-old WT and mgt10 plants grown in the same pot. Values are means ± SE (n = 3). Each replicate contained 10 plants. *P < 0.05, **P < 0.01, Student's t-test. DW, dry weight. (I) Mg2+ content of intact chloroplasts isolated from 14-day-old seedlings grown on half MS medium supplemented with 1% sucrose. Values are means ± SE (n = 9). **P < 0.01, Student's t-test.
(J) Mg2+ concentrations in xylem saps, which were sampled from the stems of 40-day-old WT and mgt10 plants grown in the same pot treated with water, 10 or 40 mM MgSO4 for 6 h. Values are means ± SE (n = 3). Each replicate contained 10 plants.
(K and L) Sucrose and/or low light (K) but not Mg2+ (L) partially rescued the defect of mgt10 in chloroplast development, compared with (G). Representative seedlings were 11 days old. Bars, 1 mm.
Molecular Plant  , DOI: ( /j.molp )
Copyright © 2017 The Author Terms and Conditions