Data from: Does stomatal patterning in amphistomatous leaves minimize the CO2 diffusion path length within leaves?
Data files
Mar 12, 2024 version files 165.58 KB
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README.md
1.34 KB
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stomata_position.csv
164.24 KB
Abstract
Photosynthesis is co-limited by multiple factors depending on the plant and its environment. These include biochemical rate limitations, internal and external water potentials, temperature, irradiance, and carbon dioxide (CO2). Amphistomatous leaves have stomata on both abaxial and adaxial leaf surfaces. This feature is considered an adaptation to alleviate CO2 diffusion limitations in productive environments as the diffusion path length from stomate to chloroplast is effectively halved in amphistomatous leaves. Plants may also reduce CO2 limitations through other aspects of optimal stomatal anatomy: stomatal density, distribution, patterning, and size. A number of studies have demonstrated that stomata are overdispersed compared to a random distribution on a single leaf surface; however, despite their prevelance in nature and near ubiquity among crop species, much less is known about stomatal anatomy in amphistomatous leaves, especially the coordination between leaf surfaces. Here we use novel spatial statistics based on simulations and photosynthesis modeling to test hypotheses about how amphistomatous plants may optimize CO2 diffusion in the model angiosperm Arabidopsis thaliana grown in different light environments. We find that 1) stomata are overdispersed, but not ideally dispersed, on both leaf surfaces across all light treatments; 2) the patterning of stomata on abaxial and adaxial leaf surfaces is independent; and 3) the theoretical improvements to photosynthesis from abaxial-adaxial stomatal coordination are miniscule (≪ 1%) across the range of feasible parameter space. However, we also find that 4) stomatal size is correlated with the mesophyll volume that it supplies with CO2, suggesting that plants may optimize CO2 diffusion limitations through alternative pathways other than ideal, uniform stomatal spacing. We discuss the developmental, physical, and evolutionary constraits which may prohibit plants from reaching this theoretical adaptive peak of uniform stomatal spacing and inter-surface stomatal coordination. These findings contribute to our understanding of variation in the anatomy of amphistomatous leaves.
https://doi.org/10.5061/dryad.44j0zpcn6
The dataset contains the x and y coordinates (in pixels), angle, and length (in pixels) of each stomate on each leaf surface from 66 Arabidopsis thaliana (Col-0 ecotype) plants grown under low, medium, and high light treatments.
Description of the data and file structure
| Variable | Type | Description |
|---|---|---|
light |
character | light treatment (low, medium, high) |
surface |
character | leaf surface (abaxial or adaxial) |
leaf_id |
character | integer leaf id within light treatment |
x |
numeric | x position of stomate in pixels |
y |
numeric | y position of stomate in pixels |
length |
numeric | guard cell length in pixels |
Each pixel is 0.824 um.
Sharing/Access information
The raw data and code to analyze it are also publicly accessible from these locations:
Plants from the Columbia (Col-0) ecotype of Arabidopsis thaliana (L.) Heynh. were grown in three different light environments: low light (PAR = 50 μmol m-2 s-1), medium light (100 μmol m-2 s-1), and high light (200 μmol m-2 s-1). PAR stands for photosynthetically active radiation. Seeds were surface-sterilized and stratified at 4 °C for 3–5 d in 0.15% agarose solution and then sown directly into Pro-Mix HP soil (Premier Horticulture; Quakerstown, PA, USA) and supplemented with Scott's Osmocote Classic 14-14-14 fertilizer (Scotts-Sierra, Marysville, OH, USA). At 10–14 d, seedlings were thinned so only one seedling per container remained. Plants were grown to maturity in growth chambers where the conditions were as follows: 16 : 8 h, 22 : 20°C, day : night cycle. Imaging of the epidermis and internal leaf structures was performed using a Leica SP5 confocal microscope (Leica Microsystems, Wetzlar, Germany) with the protocol developed by Wuyts et al. (2010) with additional modification described in Dow et al. (2017). We captured 132 images in total, making 66 abaxial-adaxial image pairs. Images were square with an area of 0.386 mm2. We measured stomatal position and length using ImageJ (Schneider et al. 2012).
References
G. J. Dow, J. A. Berry, and D. C. Bergmann. Disruption of stomatal lineage signaling or transcriptional regulators has differential effects on mesophyll development, but maintains coordination of gas exchange. New Phytologist, 216(1):69–75, Oct. 2017. ISSN 0028-646X, 1469-8137. doi: 10.1111/nph.14746. URL https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.14746.
C. A. Schneider, W. S. Rasband, and K. W. Eliceiri. NIH Image to ImageJ: 25 years of image analysis. Nature Methods, 9(7):671–675, July 2012. ISSN 1548-7091, 1548-7105. doi: 10.1038/nmeth.2089. URL http://www.nature.com/articles/nmeth.2089.
N. Wuyts, J.-C. Palauqui, G. Conejero, J.-L. Verdeil, C. Granier, and C. Massonnet. High-contrast three-dimensional imaging of the Arabidopsis leaf enables the analysis of cell dimensions in the epidermis and mesophyll. Plant Methods, 6(1):17, Dec. 2010. ISSN 1746-4811. doi: 10.1186/1746-4811-6-17. URL https://plantmethods.biomedcentral.com/articles/10.1186/1746-4811-6-17.