The membrane potential of Arabidopsis thaliana guard cells; depolarizations induced by apoplastic acidification

The role and the interrelationship of cytosolic alkalisation and nitric oxide (NO) in UVB-induced stomatal closure were investigated in Arabidopsis thaliana (L.) Heynh. by stomatal bioassay and laser-scanning confocal microscopy. In response to 0.5 W m–2 UVB radiation, the rise of NO levels in guard cells occurred after cytosolic alkalisation but preceded stomatal closure. UVB-induced NO production and stomatal closure were both inhibited by NO scavengers, nitrate reductase (NR) inhibitors and a Nia2–5/Nia1–2 mutation, and also by butyrate. Methylamine induced NO generation and stomatal closure in the wild-type but not in the Nia2–5/Nia1–2 mutant or wild-type plants pretreated with NO scavengers or NR inhibitors while enhancing the cytosolic pH in guard cells under light. NO generation in wild-type guard cells was largely induced after 60 min of UVB radiation. The defect in UVB-induced NO generation in Nia2–5/Nia1–2 guard cells did not affect the changes of guard cell pH before 60 min of UVB radiation, but prevented the UVB-induced cytosolic alkalisation after 60 min of radiation. Meanwhile, exogenous NO caused a marked rise of cytosolic pH in guard cells. Together, our results show that cytosolic alkalisation and NR-dependent NO production coordinately function in UVB signalling in A. thaliana guard cells.

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Promoters from kin1 and co6.6, two Arabidopsis thaliana low-temperature- and ABA-inducible genes, direct strong ?-glucuronidase expression in guard cells, pollen and young developing seeds

Plant Molecular Biology ◽

10.1007/bf00020472 ◽

1995 ◽

Vol 29 (6) ◽

pp. 1307-1307 ◽

Cited By ~ 1

Author(s):

Hong Wang ◽

Adrian J. Cutler

Keyword(s):

Arabidopsis Thaliana ◽

Low Temperature ◽

Guard Cells ◽

Developing Seeds ◽

Inducible Genes

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Chromatin of endoreduplicated pavement cells has greater range of movement than that of diploid guard cells in Arabidopsis thaliana

Journal of Cell Science ◽

10.1242/jcs.00437 ◽

2003 ◽

Vol 116 (11) ◽

pp. 2195-2201 ◽

Cited By ~ 49

Author(s):

N. Kato

Keyword(s):

Arabidopsis Thaliana ◽

Guard Cells ◽

Range Of Movement ◽

Pavement Cells

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Starch Granules in Arabidopsis thaliana Mesophyll and Guard Cells Show Similar Morphology but Differences in Size and Number

International Journal of Molecular Sciences ◽

10.3390/ijms22115666 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5666

Author(s):

Qingting Liu ◽

Xiaoping Li ◽

Joerg Fettke

Keyword(s):

Arabidopsis Thaliana ◽

Starch Synthesis ◽

Guard Cells ◽

Morphological Properties ◽

Fast Method ◽

Starch Granules ◽

Mesophyll Cells ◽

Laser Confocal Scanning Microscopy ◽

Transitory Starch ◽

Confocal Scanning

Transitory starch granules result from complex carbon turnover and display specific situations during starch synthesis and degradation. The fundamental mechanisms that specify starch granule characteristics, such as granule size, morphology, and the number per chloroplast, are largely unknown. However, transitory starch is found in the various cells of the leaves of Arabidopsis thaliana, but comparative analyses are lacking. Here, we adopted a fast method of laser confocal scanning microscopy to analyze the starch granules in a series of Arabidopsis mutants with altered starch metabolism. This allowed us to separately analyze the starch particles in the mesophyll and in guard cells. In all mutants, the guard cells were always found to contain more but smaller plastidial starch granules than mesophyll cells. The morphological properties of the starch granules, however, were indiscernible or identical in both types of leaf cells.

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