Increased stomatal densities in sdd1-1 enabled low-light-adapted plants to have 30% higher CO(2) assimilation rates compared to the wild type

Photosynthetic performance of an Arabidopsis mutant with elevated stomatal density (sdd1–1) under different light regimes

Schlüter U., Muschak M., Berger D., Altmann T. (2003)

Urte Schlüter, Michael Muschak, Dieter Berger, Thomas Altmann,

Max-Planck-Institute of Molecular Plant Physiology, Am Muhlenberg 1, D-14424 Golm, Germany

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J. Exp. Bot. 54: 867–874 – PMID: 12554730 – DOI: 10.1093/jxb/erg087 –

https://pubmed.ncbi.nlm.nih.gov/12554730

Abstract

In the Arabidopsis mutant sdd1-1, a point mutation in a single gene (SDD1) causes specific alterations in stomatal density and distribution. In comparison to the wild type (C24), abaxial surfaces of sdd1-1 rosette leaves have about 2.5-fold higher stomatal densities. This mutant was used to study the consequence of stomatal density on photosynthesis under various light regimes. The increased stomatal density in the mutant had no significant influence on the leaf CO(2) assimilation rate (A) under constant light conditions. Mutant and wild-type plants contained similar amounts of carbohydrates under these conditions. However, exposure of plants to increasing photon flux densities resulted in differences in gas exchange and the carbohydrate metabolism of the wild type and mutant. Increased stomatal densities in sdd1-1 enabled low-light-adapted plants to have 30% higher CO(2) assimilation rates compared to the wild type when exposed to high light intensities. After 2 d under high light conditions leaves of sdd1-1 accumulated 30% higher levels of starch and hexoses than wild-type plants.

A point mutation in a single gene (SDD1) causes specific alterations in stomatal density and distribution

 

 

Photosynthetic performance of an Arabidopsis mutant with elevated stomatal density (sdd1-1) under different light regimes

by Schlüter U., Muschak M., Berger D., Altmann T. (2003)

Urte Schlüter, Heinrich-Heine-Universität Düsseldorf, Germany

Michael Muschak, Max Planck Institute of Molecular Plant Physiology (Potsdam, Germany)

Dieter Berger, Universität Potsdam (Potsdam, Germany)

Thomas Altmann, Julius Kühn-Institut (Quedlinburg, Germany)

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in J Exp Bot 54: 867–874 – https://doi.org/10.1093/jxb/erg087 – 

CrossRefPubMedGoogle Scholar – 

https://academic.oup.com/jxb/article/54/383/867/545860

Abstract

In the Arabidopsis mutant sdd1‐1, a point mutation in a single gene (SDD1) causes specific alterations in stomatal density and distribution.

In comparison to the wild type (C24), abaxial surfaces of sdd1‐1 rosette leaves have about 2.5‐fold higher stomatal densities. This mutant was used to study the consequence of stomatal density on photosynthesis under various light regimes.

The increased stomatal density in the mutant had no significant influence on the leaf CO₂ assimilation rate (A) under constant light conditions. Mutant and wild‐type plants contained similar amounts of carbohydrates under these conditions. However, exposure of plants to increasing photon flux densities resulted in differences in gas exchange and the carbohydrate metabolism of the wild type and mutant.

Increased stomatal densities in sdd1‐1 enabled low‐light‐adapted plants to have 30% higher CO₂ assimilation rates compared to the wild type when exposed to high light intensities.

After 2 d under high light conditions leaves of sdd1‐1 accumulated 30% higher levels of starch and hexoses than wild‐type plants.

The SDD1 gene and stomata

Habitus of wild-type and sdd1-1, increase of stomatal density, formation of paired stomata in leaves ofsdd1-1, and cross sections of rosette leaves of wild-type and mutant. Macroscopically, wild type (A) and sdd1-1(B) show no differences in morphology. Alteration in stomatal density is shown in images of the abaxial surfaces of rosette leaves of the transgenic wild-type control (C) and of thesdd1-1 mutant (D). Bars, 200 μm. Paired stomata in sdd1-1 are indicated in D by arrowheads and shown in higher magnification in F in comparison to single stomata in the wild type (E). Bars, 10 μm. For better visibility, guard cells expressing β-glucuronidase were histochemically stained with X-gluc. Cross sections of rosette leaves of wild type (G) and sdd1-1 (H) demonstrate that the structure or arrangement of internal leaf tissues is not affected by thesdd1-1 mutation. Large substomatal cavities are present at some but not all stomata present in sdd1-1 leaves. Bars, 25 μm.

A subtilisin-like serine protease involved in the regulation of stomatal density and distribution in Arabidopsis thaliana.

by Berger D., Altmann T. (2000)

1. Dieter Berger,
2. Thomas Altmann,

in Gene Dev 14:1119–1131. – doi:10.1101/gad.14.9.1119

Abstract/FREE Full Text

http://genesdev.cshlp.org/content/14/9/1119.abstract?ijkey=106f9f0a794e6039b374d8eb50698e4e1e0fed6d&keytype2=tf_ipsecsha

http://genesdev.cshlp.org/content/14/9/1119.full.html

Abstract

Stomata are specialized cellular structures in the epidermis of aerial plant organs that control gas exchange (H₂O release and CO₂ uptake) between leaves and the atmosphere by modulating the aperture of a pore flanked by two guard cells.

Stomata are nonrandomly distributed, and their density is controlled by endogenous and environmental factors.

To gain insight into the molecular mechanisms regulating stomatal distribution, Arabidopsis thaliana mutants with altered stomatal characteristics were isolated and examined.

The sdd1-1 mutant exhibits a two- to fourfold increase of stomatal density and formation of clustered stomata (i.e., stomata that are not separated by intervening pavement cells), whereas the internal leaf architecture is not altered.

The SDD1 gene was identified by map-based cloning. It encodes a subtilisin-like serine protease related to prokaryotic and eukaryotic proteins.

We propose that SDD1 acts as a processing protease involved in the mediation of a signal that controls the development of cell lineages that lead to guard cell formation.