Speedy grass stomata

 

Speedy grass stomata: Emerging molecular and evolutionary features

by Cai S., Papanatsiou M., Blatt M. R., Chen Z.-H. ( 2017)

Shengguan Cai

media_203443_en
Michael R. Blatt, University of Glasgow

in Molecular Plant xxxx –

https://www.researchgate.net/publication/317508978_Speedy_Grass_Stomata_Emerging_Molecular_and_Evolutionary_Features

(No abstract available)

Oxygen, light, CO2 and stomata

 

Oxygen-dependent stomatal opening in Zea mays leaves—effect of light and carbon-dioxide.

by Vavasseur A.Lasceve G.Couchat P. (1988)

Alain Vavasseur, Centre d’Etudes Nucléaires, F-13108 Saint-Paul-lez-Durance, Cedex, France.

Gérard Lascève, Centre d’Etudes Nucléaires, F-13108 Saint-Paul-lez-Durance, Cedex, France.

Philippe Couchat, Centre d’Etudes Nucléaires, F-13108 Saint-Paul-lez-Durance, Cedex, France.

in Physiologia Plantarum 1988;73:547552. – DOI: 10.1111/j.1399-3054.1988.tb05439.x

Google Scholar – 

http://onlinelibrary.wiley.com/doi/10.1111/j.1399-3054.1988.tb05439.x/full

Abstract

The oxygen requirement for stomatal opening in maize plants (Zea mays L. hybrid INRA 508) was studied at different CO2 concentrations and light intensities. In the absence of CO2, stomatal opening always required O2, but this requirement decreased with increasing light intensity. In darkness, the lowest O2 partial pressure needed to obtain a weak stomatal movement was about 50 Pa. This value was lowered to ca 10 Pa in light (320 μmol m−2 s−1).

On the other hand. in the absence of O2, CO2enabled stomatal opening to occur in the light, presumably due to the evolved photosynthetic O2. Thus, CO2, which generally reduced stomatal aperture, could induce stomatal movement in anoxia and light.

The effect of CO2 on stomatal opening was closely dependent on O2 concentration and light intensity. Stomatal aperture appeared CO2-independent at an O2 partial pressure which was dependent on light intensity and was about 25 Pa at 320 umol m−2 s−1.

The presence of a plasmalemma oxidase, in addition to mitochondrial oxidase, might explain the differences in the O2 requirement at various light intensities. The possible involvement of such a system in relation to the effect of CO2 is discussed.

Mg-chelatase complex as a whole affects the ABA-signaling pathway for stomatal movements.

 

Mg-chelatase H subunit affects ABA signaling in stomatal guard cells, but is not an ABA receptor in Arabidopsis thaliana.

by Tsuzuki T., Takahashi K., Inoue S. I., Okigaki Y., Tomiyama M., Hossain M. A., Shimazaki K. I., Murata Y., Kinoshita T. (2011)

  • Tomo Tsuzuki
  • Koji Takahashi
  • Shin-ichiro Inoue
  • Yukiko Okigaki
  • Masakazu Tomiyama
  • Mohammad Anowar Hossain
  • Ken-ichiro Shimazaki
  • Yoshiyuki Murata
  • Toshinori Kinoshita

in J Plant Res. 2011 Jul 124(4):527-38. Epub 2011 May 12. – doi:10.1007/s10265-011-0426-x pmid:21562844

Abstract

Mg-chelatase H subunit (CHLH) is a multifunctional protein involved in chlorophyll synthesis, plastid-to-nucleus retrograde signaling, and ABA perception. However, whether CHLH acts as an actual ABA receptor remains controversial.

Here we present evidence that CHLH affects ABA signaling in stomatal guard cells but is not itself an ABA receptor. We screened ethyl methanesulfonate-treated Arabidopsis thaliana plants with a focus on stomatal aperture-dependent water loss in detached leaves and isolated a rapid transpiration in detached leaves 1 (rtl1) mutant that we identified as a novel missense mutant of CHLH.

The rtl1 and CHLH RNAi plants showed phenotypes in which stomatal movements were insensitive to ABA, while the rtl1 phenotype showed normal sensitivity to ABA with respect to seed germination and root growth.

ABA-binding analyses using 3H-labeled ABA revealed that recombinant CHLH did not bind ABA, but recombinant pyrabactin resistance 1, a reliable ABA receptor used as a control, showed specific binding. Moreover, we found that the rtl1 mutant showed ABA-induced stomatal closure when a high concentration of extracellular Ca2+ was present and that a knockout mutant of Mg-chelatase I subunit (chli1) showed the same ABA-insensitive phenotype as rtl1.

These results suggest that the Mg-chelatase complex as a whole affects the ABA-signaling pathway for stomatal movements.

Stomatal and non-stomatal limitations to photosynthesis in four tree species

 

Stomatal and non-stomatal limitations to photosynthesis in four tree species in a temperate rainforest dominated by Dacrydium cupressinum in New Zealand.

by Tissue D. T.Griffin K. L.Turnbull M.H.Whitehead D. (2005)

 

in Tree Physiology2005;25:447456. – DOI: https://doi.org/10.1093/treephys/25.4.447

(Abstract/FREE Full Text) – 

https://academic.oup.com/treephys/article/25/4/447/1659563/Stomatal-and-non-stomatal-limitations-to

Abstract

We assessed the relative limitations to photosynthesis imposed by stomatal and non-stomatal processes in Dacrydium cupressinum Lamb. (Podocarpaceae), which is the dominant species in a native, mixed conifer—broad-leaved rainforest in New Zealand.

For comparison, we included three cooccurring broad-leaved tree species (Meterosideros umbellata Cav. (Myrtaceae), Weinmannia racemosa L.f. (Cunoniaceae) and Quintinia acutifolia Kirk (Escalloniaceae)) that differ in phylogeny and in leaf morphology from D. cupressinum.

We found that low foliage phosphorus content on an area basis (Pa) limited light-saturated photosynthesis on an area basis (Asat) in Q. acutifolia. Depth in the canopy did not generally affect Asat or the relative limitations to Asat because of stomatal and non-stomatal constraints, despite reductions in the ratio of foliage mass to area, foliar nitrogen on an area basis (Na) and Pa with depth in the canopy.

In the canopy-dominant conifer D. cupressinum, Asat was low, consistent with low values of the maximum rate of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (Vcmax).

In comparison, the Asat response of the three broad-leaved tree species was quite variable. Although Asat was high in the canopy-dominant M. umbellata, it was low in the sub-canopy trees W. racemosa and Q. acutifolia. Relative stomatal limitation to photosynthesis was more pronounced in W. racemosa (40%) than in the other three species (28–33%). Despite differences in degree, non-stomatal limitation to Asat predominated in all tree species.