scholarly journals C4 photosynthesis with Kranz anatomy evolved in the Oryza coarctata Roxb

2020 ◽  
Author(s):  
Soni Chowrasia ◽  
Tapan Kumar Mondal
Keyword(s):  
C4 Photosynthesis ◽  
Expression Patterns ◽  
Bundle Sheath ◽  
Ultrastructural Observation ◽  
Mesophyll Cells ◽  
Potential Donor ◽  
Kranz Anatomy ◽  
Vein Density ◽  
Bundle Sheath Cells ◽  
Sheath Cells

AbstractThe C4 cycle is a complex biochemical pathway that has been evolved in plants to deal with the adverse environmental conditions. Mostly C4 plants grow in arid, water-logged area or poor nutrient habitats. Wild species, Oryza coarctata (genome type KKLL; chromosome number (4x) =48, genome size 665 Mb) belongs to the genus of Oryza which thrives well under high saline as well as submerged conditions. Here, we report for the first time that O. coarctata is a C4 plant by observing the increased biomass growth, morphological features such as vein density, anatomical features including ultrastuctural characteristics as well as expression patterns of C4 related genes. Leaves of O. coarctata have higher vein density and possess Kranz anatomy. The ultrastructural observation showed chloroplast dimorphism i.e. presence of agranal chloroplasts in bundle sheath cells whereas, mesophyll cells contain granal chloroplasts. The cell walls of bundle sheath cells contain tangential suberin lamella. The transcript level of C4 specific genes such as phosphoenolpyruvate carboxylase, pyruvate orthophosphate dikinase, NADP-dependent malic enzyme and malate dehydrogenase was higher in leaves of O. coarctata compare to high yielding rice cultivar (IR-29). These anatomical, ultra structural as well as molecular changes in O. coarctata for C4 photosynthesis adaptation might be might be due to its survival in wide diverse condition from aquatic to saline submerged condition. Being in the genus of Oryza, this plant could be potential donor for production of C4 rice in future through conventional breeding, as successful cross with rice has already been reported.

Phenolic Deposits and Kranz Syndrome in Leaf Tissues of Spotted (Euphorbia maculata) and Prostrate (Euphorbia supina) Spurge

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 131-136 ◽  
Author(s):  
C. Dennis Elmore ◽  
Rex N. Paul
Keyword(s):  
Electron Microscopy ◽  
Phenolic Compounds ◽  
Light And Electron Microscopy ◽  
Bundle Sheath ◽  
Fixation Technique ◽  
Mesophyll Cells ◽  
Kranz Anatomy ◽  
Bundle Sheath Cells ◽  
Leaf Tissues ◽  
Sheath Cells

Spotted spurge (Euphorbia maculataL.) and prostrate spurge (E. supinaRaf.), both in subgenusChamesyce,were examined by light and electron microscopy using a caffeine - fixation technique to sequester the phenolic pools intercellularly. Both species have typical dicotyledon-type Kranz anatomy. Sequestered phenolic pools were located in vacuoles in epidermal and mesophyll cells. Only in spotted spurge, however, were additional phenolic pools formed in bundle - sheath cells. This study was undertaken because allelopathy has been demonstrated in prostrate spurge and because phenolic compounds have been implicated in allelopathy. These results would indicate that spotted spurge should also be allelopathic.

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.

Nitrate metabolism in relation to the aspartate-type C-4 pathway of photosynthesis in Eleusine coracana

1974 ◽  
Vol 52 (12) ◽  
pp. 2599-2605 ◽  
Author(s):  
C. K. M. Rathnam ◽  
V. S. R. Das
Keyword(s):  
Glutamate Dehydrogenase ◽  
Eleusine Coracana ◽  
Bundle Sheath ◽  
Chloroplast Envelope ◽  
Mesophyll Cells ◽  
Bundle Sheath Cells ◽  
Nitrate Metabolism ◽  
Type C ◽  
Envelope Membranes ◽  
Sheath Cells

The intercellular and intracellular distributions of nitrate assimilating enzymes were studied. Nitrate reductase was found to be localized on the chloroplast envelope membranes. The chloroplastic NADPH – glutamate dehydrogenase was concentrated in the mesophyll cells. The extrachloroplastic NADH – glutamate dehydrogenase was localized in the bundle sheath cells. Glutamate synthesized in the mesophyll chloroplasts was interpreted to be utilized exclusively in the synthesis of aspartate, while in the bundle sheath cells it was thought to be consumed in other cellular metabolic processes. Based on the results, a scheme is proposed to account for the nitrate metabolism in the leaves of Eleusine coracana Gaertn. in relation to its aspartate-type C-4 pathway of photosynthesis.

scholarly journals Measurement of the Leakage of CO2 from Bundle-Sheath Cells of Leaves during C4 Photosynthesis

1995 ◽  
Vol 108 (1) ◽  
pp. 173-181 ◽  
Author(s):  
M. D. Hatch ◽  
A. Agostino ◽  
CLD. Jenkins
Keyword(s):  
C4 Photosynthesis ◽  
Bundle Sheath ◽  
Bundle Sheath Cells ◽  
Sheath Cells

Photosynthesis in Gomphrena celosioides and Its Classification Amongst C4-pathway Plants

1976 ◽  
Vol 3 (6) ◽  
pp. 863 ◽  
Author(s):  
E Repo ◽  
MD Hatch
Keyword(s):  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Bundle Sheath ◽  
Mesophyll Cells ◽  
C4 Species ◽  
Bundle Sheath Cells ◽  
Major Route ◽  
Gomphrena Celosioides ◽  
A Minor ◽  
Sheath Cells

Monocotyledonous C4 species classified as NADP-ME-type transfer malate from mesophyll to bundle sheath cells where this acid is decarboxylated via NADP malic enzyme (EC 1.1.1.40) to yield pyruvate and CO2. The dicotyledon G. celosioides is most appropriately classified in thls group on the basis of high leaf activities of NADP malic enzyme and NADP malate dehydrogenase (EC 1.1.1.82). However, this species contains high aspartate aminotransferase (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2) activities and centripetally located bundle sheath chloroplasts, features more typical of other groups of C4 species that cycle aspartate and alanine between mesophyll and bundle sheath cells. During the present study, we found that these aminotransferases and NADP malate dehydrogenase were predominantly located in mesophyll cells, that malate was the major C4 acid labelled when leaves were exposed to 14CO2, and that label was initially lost most rapidly from the C-4 of malate during a chase in 12CO2. These results are consistent with the major route of photosynthetic metabolism being the same as that operative in other NADP-ME-type species, although this may be supplemented by a minor route utilizing aspartate. In contrast to monocotyledonous NADP-ME-type C4 species, isolated bundle sheath cells from G. celosioides were capable of rapid photoreduction of NADP as judged by products formed during assimilation of 14CO2 and their capacity for light-dependent oxygen evolution. This was related to a relatively high frequency of single unstacked granum in the chloroplasts of these cells.

scholarly journals Arabidopsis leaf hydraulic conductance is regulated by xylem-sap pH, controlled, in turn, by a P-type H+-ATPase of vascular bundle sheath cells

2017 ◽  
Author(s):  
Yael Grunwald ◽  
Noa Wigoda ◽  
Nir Sade ◽  
Adi Yaaran ◽  
Tanmayee Torne ◽  
...  
Keyword(s):  
Proton Pump ◽  
Vascular Bundle ◽  
Xylem Sap ◽  
Hydraulic Conductance ◽  
Bundle Sheath ◽  
List Type ◽  
Mesophyll Cells ◽  
Leaf Hydraulic Conductance ◽  
Bundle Sheath Cells ◽  
Sheath Cells

AbstractThe leaf vascular bundle sheath cells (BSCs) that tightly envelop the leaf veins, are a selective and dynamic barrier to xylem-sap water and solutes radially entering the mesophyll cells. Under normal conditions, xylem-sap pH of <6 is presumably important for driving and regulating the transmembranal solute transport. Having discovered recently a differentially high expression of a BSCs proton pump, AHA2, we now test the hypothesis that it regulates this pH and leaf radial water fluxes.We monitored the xylem-sap pH in the veins of detached leaves of WT Arabidopsis, AHA mutants, and aha2 mutants complemented with AHA2 gene solely in BSCs. We tested an AHA inhibitor and stimulator, and different pH buffers. We monitored their impact on the xylem-sap pH and the whole leaf hydraulic conductance (Kleaf), and the effect of pH on the water osmotic permeability (Pf) of isolated BSCs protoplasts.Our results demonstrated that AHA2 is necessary for xylem-sap acidification, and in turn, for elevating Kleaf. Conversely, knocking out AHA2 alkalinized the xylem-sap. Also, elevating xylem sap pH to 7.5 reduced Kleaf and elevating external pH to 7.5 decreased the BSCs Pf.All these demonstrate a causative link between AHA2 activity in BSCs and leaf radial water conductance.One-sentence summaryBundle-sheath cells can control the leaf hydraulic conductance by proton-pump-regulated xylem sap pH

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