Poisson distribution fitness (δ) of leaf wounding and dark count data.

<p>Aerobic wound data surpassed PMT dark counts (2/3 samples). (Δ) Indicates the difference in photocounts from basal—wounding peak and correlates with the degree of divergence from Poisson. Aerobic pre-wound, post-wound end, and anoxic (δ) values show close agreement with a Poisson distribution. (Letters = leaves where indicated).</p

Aerobic wound decay trends.

<p>Typical hyperbolic and dual post wound exponential decays (in air). (A) Complete fluorescent decay/dark adapt—wounding profile. (B) Enlarged view of wounding data. Note primary and secondary post wound decays. Red curve is 25-point data smoothing for trend visibility.</p

Aerobic post wound secondary decay photocount distributions.

<p>Photon count statistics of leaves (A-C) approach a Poissonian distribution upon exponential decay relaxation (last 800 s before closing shutter). (μ_A = 34.32; μ_B = 44.06 and μ_C = 18.90).</p

Experiment layout and test equipment.

<p>(A) Overview of lab and dark room. (B) Photon counting experiment set up.</p

<i>Spathiphyllum</i> dark-adaptation decay plots.

<p>Nine sample decay plots of dark-adapting <i>Spathiphyllum</i>. Purple curve (and inset) depicts the sample average. Enlarged scale of basal count (1.5–2.0 hrs.) reveals 32 cps after two hours. Average dark count is 5 cps.</p

Aerobic post wound secondary exponential decay.

<p>Leaves A, B, & C photocounts with double exponential decay fit line (red) (A-C). Leaf B (B) did not display a secondary decay peak. Cyan curve in (B) is 10 pt smoothed to highlight the decay profile. Red lines (A, C) reflect double exponential curve fit. (D-F) Observed photon count frequency vs. Poisson predicted distribution for each leaf (μ_A = 48.55; μ_B = 64.19 and μ_C = 25.90).</p

<i>Spathiphyllum</i> wounding UPE while under anoxic stress (Nitrogen gas).

<p>Moderate increase in photocounts was observed upon anoxic wounding in leaves (D, F). No increase in counts was observed with leaf (E). 25 point smoothing of curve data was used for data visualization.</p

Anoxic wounding photocount distributions.

<p>(A-C) Photocount statistics of leaf anoxic wound data. Observed photon count frequencies closely approximate a Poisson predicted distribution (μ_D = 22.10; μ_E = 15.96 and μ_F = 21.34).</p

Plant test enclosure.

<p><i>Spathiphyllum</i> in plant enclosure (S). Shown with single filter lens assembly and front panel removed.</p

Primary photon counting lens and PMT assembly.

<p>Primary PMT lens configuration with matched achromatic doublet pair lens (<i>f</i> = 40 mm) and mechanical shutter (SHB1T). Single edgepass filters were manually inserted as indicated when used for spectroscopy measurements.</p