Fig. 2: The chloroplasts in Norway spruce are more sensitive to photodamage during the spring recovery period compared with the chloroplasts in Scots pine.
From: Two dominant boreal conifers use contrasting mechanisms to reactivate photosynthesis in the spring
a Transmission electron micrographs (TEM) of chloroplast structures in needles from Scots pine and Norway spruce collected in the field during March and April. Representative images are shown. Bar: 0.5 μm. gt grana thylakoid (stacked), st stromal thylakoid (unstacked), pg plastoglobulus. The TEM images from the remaining months are found in Supplementary Fig. S1. The number (b) and total area (c) of plastoglobules per chloroplast from the transmission electron micrographs from Scots pine (black) and Norway spruce (gray, mean ± SE, n = 8–12). d Malondialdehyde (MDA) content in Scots pine (black) and Norway spruce (gray) needles. Samples were collected from February to June, and each data point represents the mean of four replicates (mean ± SE, n = 4). Significant differences were indicated with different letters above the bars (one-way ANOVA, P < 0.05).
