The Ultrastructural Development of the Dimorphic Plastids of Zea Mays L.

Kirchanski, Stefan J.

doi:10.1002/j.1537-2197.1975.tb14102.x

Cited by 39 publications

(32 citation statements)

References 24 publications

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“…Hence, the NADPH/NADP ratio affects the electron transport chain (Takabayashi et al, 2005). The input of NADPH via malate decarboxylation in BSC does not inhibit photosynthesis, because it merely compensates for insufficient NADPH synthesis in BSC, which lack PSII activity (Kirchanscki, 1975). In C3 plants, chloroplasts in MC have normal PSII activity, so the electron transport chain is inhibited by large amounts of malate entering the MC chloroplasts, leading to the generation of reactive oxygen species and photodamage to PSII complexes.…”

Section: Discussionmentioning

confidence: 99%

Exogenous Malate Application Inhibits the Photochemical Activity of Photosystem II in Rice Leaves

Cui¹,

Yue²,

Zhang³

et al. 2015

IJAB

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Malate is a carrier that transfers CO2 and NADPH from mesophyll cells (MC) to vascular bundle sheath cells (BSC) in C4 plant photosynthesis. It likely plays a key role in regulating photosystem II (PSII) photochemical activity. We used the C3 plant rice to study the effect of exogenous malate (200 μM) from roots on PSII activity. The malate treatment increased leaf malate content, NADPH/NADP ratio, and the initial fluorescence yield (F0) and decreased photosynthetic oxygen evolution, the maximum fluorescence (Fm), the maximal efficiency of PS II photochemistry (Fv/Fm), and the number of active PSII reaction centers per excited cross section (RC/CSm). Malate treatment also increased the initial fluorescence yield (F0′) and decreased the maximum fluorescence (Fm′) and maximal efficiency of PS II photochemistry (Fv′/Fm′) from light-adapted leaves. Based on these results, we concluded that higher concentrations of exogenous malate inhibit photosynthesis and PSII photochemical activity, perhaps in part because of the rise in NADPH/NADP ratio in chloroplasts in C3 rice plants.

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Section: Discussionmentioning

confidence: 99%

Exogenous Malate Application Inhibits the Photochemical Activity of Photosystem II in Rice Leaves

Cui¹,

Yue²,

Zhang³

et al. 2015

IJAB

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“…The altered ratio may also be due to the excess carbohydrates having a greater effect on mesophyll cells than bundle sheath cells. For example, mesophyll cells contain grana stacks that are the principal site of the chlorophyll a/b-binding protein LHCII, whereas bundle sheath cells contain mostly agranal thylakoids and lack LHCII (Kirchanksi, 1975;Schuster et al, 1985). In tdy2 chlorotic tissues, the relative increase in carbohydrate accumulation and disruption of grana stacks may be much greater in mesophyll cell chloroplasts than in bundle sheath cell plastids, which normally accumulate starch.…”

Section: Discussionmentioning

confidence: 99%

Tie-dyed2Functions withTie-dyed1to Promote Carbohydrate Export from Maize Leaves

Baker

Braun

2008

Plant Physiology

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Regulation of carbon partitioning is essential for plant growth and development. To gain insight into genes controlling carbon allocation in leaves, we identified mutants that hyperaccumulate carbohydrates. tie-dyed2 (tdy2) is a recessive mutant of maize (Zea mays) with variegated, nonclonal, chlorotic leaf sectors containing excess starch and soluble sugars. Consistent with a defect in carbon export, we found that a by-product of functional chloroplasts, likely a sugar, induces tdy2 phenotypic expression. Based on the phenotypic similarities between tdy2 and two other maize mutants with leaf carbon accumulation defects, tdy1 and sucrose export defective1 (sxd1), we investigated whether Tdy2 functioned in the same pathway as Tdy1 or Sxd1.Cytological and genetic studies demonstrate that Tdy2 and Sxd1 function independently. However, in tdy1/1; tdy2/1 F 1 plants, we observed a moderate chlorotic sectored phenotype, suggesting that the two genes are dosage sensitive and have a related function. This type of genetic interaction is referred to as second site noncomplementation and has often, though not exclusively, been found in cases where the two encoded proteins physically interact. Moreover, tdy1; tdy2 double mutants display a synergistic interaction supporting this hypothesis. Additionally, we determined that cell walls of chlorotic leaf tissues in tdy mutants contain increased cellulose; thus, tdy mutants potentially represent enhanced feedstocks for biofuels production. From our phenotypic and genetic characterizations, we propose a model whereby TDY1 and TDY2 function together in a single genetic pathway, possibly in homo-and heteromeric complexes, to promote carbon export from leaves.

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“…Thus, chloroplasts differentiate for distinct functions in the two cell types and exhibit characteristic dimorphism. Bundle sheath cells have agranal chloroplasts containing large starch granules, whereas mesophyll cells have granal chloroplasts without starch granules (Kirchanski, 1975). C 4 metabolism is effectively mediated by the close physical association of mesophyll and bundle sheath cells.…”

Section: Introductionmentioning

confidence: 99%

The Maize Golden2 Gene Defines a Novel Class of Transcriptional Regulators in Plants

et al. 2001

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In the C 4 plant maize, three photosynthetic cell types differentiate: C 4 bundle sheath, C 4 mesophyll, and C 3 mesophyll cells. C 3 mesophyll cells represent the ground state, whereas C 4 bundle sheath and C 4 mesophyll cells are specialized cells that differentiate in response to light-induced positional signals. The Golden2 ( G2 ) gene regulates plastid biogenesis in all photosynthetic cells during the C 3 stages of development. However, G2 function is specifically committed to the differentiation of bundle sheath cell chloroplasts in C 4 leaf blades. In this article, we report the isolation of G2-like ( Glk ) genes from maize and rice, providing evidence for a family of Glk genes in plants. The expression profiles of the rice Glk genes suggest that these genes may act redundantly to promote photosynthetic development in this C 3 species. In maize, G2 and ZmGlk1 transcripts accumulate primarily in C 4 bundle sheath and C 4 mesophyll cells, respectively, suggesting a specific role for each gene in C 4 differentiation. We show that G2 and ZmGLK1 both can transactivate reporter gene transcription and dimerize in yeast, which supports the idea that these proteins act as transcriptional regulators of cell-type differentiation processes.

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The Ultrastructural Development of the Dimorphic Plastids of Zea Mays L.

Cited by 39 publications

References 24 publications

Exogenous Malate Application Inhibits the Photochemical Activity of Photosystem II in Rice Leaves

Exogenous Malate Application Inhibits the Photochemical Activity of Photosystem II in Rice Leaves

Tie-dyed2Functions withTie-dyed1to Promote Carbohydrate Export from Maize Leaves

The Maize Golden2 Gene Defines a Novel Class of Transcriptional Regulators in Plants

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