Control of cellular differentiation in maize leaves

1995 ◽  
Vol 350 (1331) ◽  
pp. 53-57 ◽  
Keyword(s):  
Cellular Differentiation ◽  
Functional Characterization ◽  
Cell Types ◽  
Bundle Sheath ◽  
Gene Products ◽  
Mesophyll Cells ◽  
Bundle Sheath Cells ◽  
Maize Leaves ◽  
Single Cell Type

Mature maize leaves exhibit a series of parallel veins that are surrounded by concentric rings of bundle sheath and mesophyll cells. To identify genes that control cellular differentiation patterns in the leaf, we have isolated a group of mutations that specifically disrupt the differentiation of a single cell-type. In bundle sheath defective ( bsd ) mutant plants, bundle sheath cells fail to differentiate yet mesophyll and all other leaf cell-types develop normally. Morphological and functional characterization of specific bsd mutants ( bsd1, bsd2, bsd3, pg14 and g2 ) reveals that they differ in the degree to which bundle sheath cell differentiation is perturbed. Mutant analysis predicts roles for BSD gene products in normal development.

bundle sheath defective, a mutation that disrupts cellular differentiation in maize leaves

Development ◽  
1994 ◽  
Vol 120 (3) ◽  
pp. 673-681 ◽  
Author(s):  
J. A. Langdale ◽  
C. A. Kidner
Keyword(s):  
Gene Action ◽  
Morphological Differentiation ◽  
Cell Types ◽  
Bundle Sheath ◽  
Sheath Cell ◽  
Mesophyll Cells ◽  
Bundle Sheath Cell ◽  
Bundle Sheath Cells ◽  
Maize Leaves ◽  
Sheath Cells

Post-primordial differentiation events in developing maize leaves produce two photosynthetic cell types (bundle sheath and mesophyll) that are morphologically and biochemically distinct. We have isolated a mutation that disrupts the differentiation of one of these cell types in light-grown leaves. bundle sheath defective 1-mutable 1 (bsd1-m1) is an unstable allele that was induced by transposon mutagenesis. In the bundle sheath cells of bsd1-m1 leaves, chloroplasts differentiate aberrantly and C4 photosynthetic enzymes are absent. The development of mesophyll cells is unaffected. In dark-grown bsd1-m1 seedlings, morphological differentiation of etioplasts is only disrupted in bundle sheath cells but photosynthetic enzyme accumulation patterns are altered in both cell types. These data suggest that, during normal development, the Bsd1 gene directs the morphological differentiation of chloroplasts in a light-independent and bundle sheath cell-specific fashion. In contrast, Bsd1 gene action on photosynthetic gene expression patterns is cell-type independent in the dark (C3 state) but bundle sheath cell-specific in the light (C4 state). Current models hypothesize that C4 photosynthetic differentiation is achieved through a light-induced interaction between bundle sheath and mesophyll cells (J. A. Langdale and T. Nelson (1991) Trends in Genetics 7, 191–196). Based on the data shown in this paper, we propose that induction of the C4 state restricts Bsd1 gene action to bundle sheath cells.

scholarly journals Complementary DNA Cloning and Characterization of Ferredoxin Localized in Bundle-Sheath Cells of Maize Leaves

1999 ◽  
Vol 119 (2) ◽  
pp. 481-488 ◽  
Author(s):  
Tomohiro Matsumura ◽  
Yoko Kimata-Ariga ◽  
Hitoshi Sakakibara ◽  
Tatsuo Sugiyama ◽  
Hiroshi Murata ◽  
...  
Keyword(s):  
Bundle Sheath ◽  
Dna Cloning ◽  
Complementary Dna ◽  
Bundle Sheath Cells ◽  
Maize Leaves ◽  
Complementary Dna Cloning ◽  
Sheath Cells

scholarly journals Electron Probe Microanalysis of Potassium and Chloride in Freeze-Substituted Leaf Sections of Zea Mays

1973 ◽  
Vol 26 (5) ◽  
pp. 1015 ◽  
Author(s):  
CK Pallaghy
Keyword(s):  
Potassium Concentration ◽  
Cell Types ◽  
Bundle Sheath ◽  
Concentration Gradients ◽  
Mesophyll Cells ◽  
Transmission Electron ◽  
Bundle Sheath Cells ◽  
Scanning Transmission ◽  
Diamond Knife ◽  
Sheath Cells

Small sections of leaves were floated on distilled water under either light or dark conditions, and were freeze-substituted in a 1 % solution of osmium tetroxide in acetone at -78�C followed by embedding in an epoxy resin. Approximately I-11m-thick sections were cut using a dry diamond knife and examined by scanning transmission electron microscopy. The relative concentrations of potassium and chloride in subcellular compartments were determined using an energy dispersive X-ray analyser. The concentration of sodium in the leaf (1�7 m-equivjkg of wet tissue) was too low to be detected by this method. The spatial resolution of this technique was sufficient to distinguish between concentrations in the chloroplasts, cytoplasm, vacuole, and nuclei. The concentration of chloride in stomata and some other epidermal cells was very much higher than in either mesophyll or bundle sheath cells. The potassium concentration in some vascular cells was at least two- to threefold higher than that in mesophyll or bundle sheath cells. The Cl : K ratio in mesophyll and bundle sheath cells resembled that in the solution (0 �10) used for growing the plants. The concentration of chloride in the "free" cytoplasm of mesophyll cells was always very low. Significant differences were found in the "ion" relations of mesophyll and bundle sheath cells. Whereas the ratio of potassium concentration between the vacuole and chloroplasts of mesophyll cells was high (1 �19) in the light and low (0�65) in the dark, the opposite was true for bundle sheath cells-O� 65 and 0�86 respectively. The ratio of potassium concentration between the vacuo les of mesophyll and those of bundle sheath cells was 1 �48 in the light, but only 0�76 in the dark. These concentration gradients are discussed in relation to a possible transfer of organic acid salts of potassium between these two cell types.

scholarly journals Detection of phosphoenolpyruvate and ribulose 1,5-bisphosphate carboxylase transcripts in maize leaves by in situ hybridization with sulfonated cDNA probes.

1989 ◽  
Vol 37 (4) ◽  
pp. 423-428 ◽  
Author(s):  
C Perrot-Rechenmann ◽  
M Joannes ◽  
D Squalli ◽  
P Lebacq
Keyword(s):  
In Situ Hybridization ◽  
Cell Types ◽  
Small Subunit ◽  
Bundle Sheath ◽  
Differential Distribution ◽  
Mesophyll Cells ◽  
Bisphosphate Carboxylase ◽  
Maize Leaves ◽  
Specific Mrnas

This report outlines an efficient in situ hybridization method for locating specific mRNAs in tissue cryosections using sulfonated cDNA probes. The method involves chemical modification of DNA probes by insertion of a sulfone radical on cytosine residues, which generates a specific epitope. Sulfonated DNA is then detected by using indirect immunochemical procedure. Alternatively, antibodies conjugated to fluorescein or to alkaline phosphatase were used for mRNA detection. In situ hybridization was developed to study aspects of mesophyll and bundle sheath cell differentiation in maize leaves. Our results indicate that phosphoenolpyruvate carboxylase (PEP C) mRNA is restricted to mesophyll cells, and the nucleus-encoded mRNA of the small subunit (SSU) ribulose 1,5-bisphosphate carboxylase (RuBP C) is limited to the cytosol of bundle sheath cells. Thus, using in situ hybridization, we have demonstrated that the differential distribution of PEP C and RuBP C proteins in the two cell types also reflects the location of their mRNAs. These data imply either a tissue-specific transcriptional regulation or a selective mRNA degradation.

Ion distribution in cereal leaves: pathways and mechanisms

1993 ◽  
Vol 341 (1295) ◽  
pp. 75-86 ◽  
Keyword(s):  
Cell Types ◽  
Bundle Sheath ◽  
Transport Systems ◽  
Testable Hypothesis ◽  
Ion Distribution ◽  
Mesophyll Cells ◽  
Bundle Sheath Cells ◽  
Different Cell Types ◽  
Symplastic Pathway ◽  
Leaf Apoplast

Measurement of ion concentrations in the vacuoles of different cell types in cereal leaves using a variety of techniques indicates that ions are differentially distributed between different cell types. Thus mesophyll cells are enriched in P but contain relatively little Ca 2+ or Cl - , whereas the reverse is true for epidermal cells. Solutes reach the leaf via the transpiration stream and we consider three possible pathways which they could follow from the xylem to leaf cells. The first is a fully apoplastic mesophyll pathway in which both water and solutes move together through the leaf apoplast passing bundle sheath, mesophyll and epidermis in turn. The second is a partly symplastic mesophyll pathway in which ions and water pass into the symplast at the mestome/bundle sheath cells. Water continues to sites of evaporation via either a transcellular or symplastic pathway, but ions may be secreted back to the mesophyll apoplast and move to the epidermis along an extracellular route. The third is a vein extension pathway which provides a diffusional pathway for ions to the epidermis. A testable hypothesis for the roles of the pathways in supplying solutes to the mesophyll and epidermis is proposed and the implications of each of these pathways for transport systems in individual cell types is discussed.

Functional compartmentation of C4 photosynthesis in the triple layered chlorenchyma of Aristida (Poaceae)

2005 ◽  
Vol 32 (1) ◽  
pp. 67 ◽  
Author(s):  
Elena V. Voznesenskaya ◽  
Simon D. X. Chuong ◽  
Nuria K. Koteyeva ◽  
Gerald E. Edwards ◽  
Vincent R. Franceschi
Keyword(s):  
Vascular Tissue ◽  
C4 Photosynthesis ◽  
Cell Types ◽  
Bundle Sheath ◽  
Mesophyll Cells ◽  
Western Blots ◽  
Kranz Anatomy ◽  
Bundle Sheath Cells ◽  
Low Levels ◽  
And Function

The genus Aristida (Poaceae), is composed of species that have Kranz anatomy and C4 photosynthesis. Kranz anatomy typically consists of two photosynthetic cell types: a layer of mesophyll cells where atmospheric CO2 is fixed into C4 acids, and an internal, chlorenchymatous vascular bundle sheath to which C4 acids are transferred and then decarboxylated to donate CO2 to the C3 cycle. The anatomy of Aristida species is unusual as it has three distinct layers of chlorenchyma cells surrounding the vascular tissue: an inner bundle sheath, an outer bundle sheath and the mesophyll cells. In this study of Aristida purpurea Nutt. var. longiseta, the functions of the three layers of chlorenchyma cells relative to the C4 photosynthetic mechanism were determined using ultrastructural analysis, western blots, immunolocalisation of photosynthetic enzymes and starch histochemistry. The results indicate that mesophyll cells contain high levels of phosphoenolpyruvate carboxylase (PEPC) and pyruvate Pi dikinase (PPDK), and function to capture CO2 in the C4 cycle. The inner bundle sheath, which is high in Rubisco and contains NADP-malic enzyme and glycine decarboxylase, functions to transfer CO2 to the C3 cycle through decarboxylation of C4 acids and by decarboxylation of glycine in the glycolate pathway. The outer chlorenchymatous sheath is where ADPG pyrophosphorylase is mainly located, and this cell layer functions as the primary site of starch storage. The outer sheath, which has low levels of Rubisco and PEPC, may also have a role in refixation of any CO2 that leaks from the inner bundle sheath cells.

scholarly journals Four Mutant Alleles Elucidate the Role of the G2 Protein in the Development of C4 and C3 Photosynthesizing Maize Tissues

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 787-797
Author(s):  
Lizzie Cribb ◽  
Lisa N Hall ◽  
Jane A Langdale
Keyword(s):  
Cell Types ◽  
Bundle Sheath ◽  
Primary Role ◽  
Ribulose Bisphosphate Carboxylase ◽  
Sheath Cell ◽  
Mesophyll Cells ◽  
Phenotypic Data ◽  
Bisphosphate Carboxylase ◽  
Bundle Sheath Cell

Abstract Maize leaf blades differentiate dimorphic photosynthetic cell types, the bundle sheath and mesophyll, between which the reactions of C4 photosynthesis are partitioned. Leaf-like organs of maize such as husk leaves, however, develop a C3 pattern of differentiation whereby ribulose bisphosphate carboxylase (RuBPCase) accumulates in all photosynthetic cell types. The Golden2 (G2) gene has previously been shown to play a role in bundle sheath cell differentiation in C4 leaf blades and to play a less well-defined role in C3 maize tissues. To further analyze G2 gene function in maize, four g2 mutations have been characterized. Three of these mutations were induced by the transposable element Spm. In g2-bsd1-m1 and g2-bsd1-s1, the element is inserted in the second intron and in g2-pg14 the element is inserted in the promoter. In the fourth case, g2-R, four amino acid changes and premature polyadenylation of the G2 transcript are observed. The phenotypes conditioned by these four mutations demonstrate that the primary role of G2 in C4 leaf blades is to promote bundle sheath cell chloroplast development. C4 photosynthetic enzymes can accumulate in both bundle sheath and mesophyll cells in the absence of G2. In C3 tissue, however, G2 influences both chloroplast differentiation and photosynthetic enzyme accumulation patterns. On the basis of the phenotypic data obtained, a model that postulates how G2 acts to facilitate C4 and C3 patterns of tissue development is proposed.

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