Huang Bingxin, Li Boxi, Wang Xulei, Rao Liming, Chen Jie, Dai Yang, Wang Lichun, Wang Zhiying, Ding Lanping. Photosynthetic physiology and stress-resistant biochemical properties reveal the invasive photo-adaptation strategy of marine green alga Codium fragile[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2382-z
Citation:
Huang Bingxin, Li Boxi, Wang Xulei, Rao Liming, Chen Jie, Dai Yang, Wang Lichun, Wang Zhiying, Ding Lanping. Photosynthetic physiology and stress-resistant biochemical properties reveal the invasive photo-adaptation strategy of marine green alga Codium fragile[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2382-z
Huang Bingxin, Li Boxi, Wang Xulei, Rao Liming, Chen Jie, Dai Yang, Wang Lichun, Wang Zhiying, Ding Lanping. Photosynthetic physiology and stress-resistant biochemical properties reveal the invasive photo-adaptation strategy of marine green alga Codium fragile[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2382-z
Citation:
Huang Bingxin, Li Boxi, Wang Xulei, Rao Liming, Chen Jie, Dai Yang, Wang Lichun, Wang Zhiying, Ding Lanping. Photosynthetic physiology and stress-resistant biochemical properties reveal the invasive photo-adaptation strategy of marine green alga Codium fragile[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2382-z
Photosynthetic physiology and stress-resistant biochemical properties reveal the invasive photo-adaptation strategy of marine green alga Codium fragile
Biological invasions have become recognized as one of the greatest threats to ecosystems. Codium, a genus of invasive green algae, has frequent global outbreaks and damages local marine ecosystems. It is now generally accepted that light is one of the main factors affecting the luxuriant growth of macroalgae such as Codium. In this study, to investigate the invasive photo-adaptation strategy of Codium fragile, the photo-adaptation characteristics of C. fragile and C. cylindricum from the Nan’ ao Island of China were compared and explored. The effect of light intensity on the photosynthetic properties of the two species was investigated: the maximum quantum yield of photosystem II (Fv/Fm) of C. fragile was significantly higher at low light intensity. At a light intensity of 90 μmol/(m2·s), maximum relative electron transport rate (rETRmax) of the thalli was maximum, and the minimum saturating irradiance (Ek) was significantly increased. The photosynthetic rate (α value) of thalli was highest at a light intensity of 30 μmol/(m2·s). The photochemical quenching (qP) was enhanced but non-photochemical quenching (NPQ) was reduced at high light intensities. As for C. cylindricum, the optimal photochemical efficiency of the thalli at low light intensity was higher. High light intensity significantly reduced the rETR of the thalli. At low light intensity, α was significantly higher, Ek was significantly lower, and NPQ was also significantly decreased. The response relationship between light acclimation and antioxidant capacity of the thalli of two species of Codium was investigated: there was no significant effect of light intensity variation on the total antioxidant capacity of C. fragile. In the case of C. cylindricum, the degree of membrane lipid peroxidation was significantly increased at low light intensity, and its antioxidant capacity was significantly reduced when the light intensity was too high or too low. It can be hypothesized that the self-protection ability of C. fragile may be stronger than that of C. cylindricum under low and high light intensities, which is closely related to the strong invasiveness of C. fragile.
Figure 1. The Fv/Fm of two Codium species cultured at different light intensities. a. The Fv/Fm of C. fragile cultured at different light intensities, and b. the Fv/Fm of C. cylindricum cultured at different light intensities. Different letters (a, b, c, and d) represent significant differences among groups.
Figure 2. The comparison of the RLCs of two Codium species cultured at different light intensities, a. The comparison of RLCs of C. fragile cultured at different light intensities, and b. the comparison of RLCs of C. cylindricum cultured at different light intensities.
Figure 3. The rETRmax, photosynthetic rate in the light-limited region of RLC (α), and Ek of two Codium species cultured at different light intensities. The data were obtained from RLCs. a. The comparison of rETRmax of C. fragile cultured at different light intensities, b. the comparison of rETRmax of C. cylindricum cultured at different light intensities, c. the comparison of α of C. fragile cultured at different light intensities, d. the comparison of α of C. cylindricum cultured at different light intensities, e. the comparison of Ek of C. fragile cultured at different light intensities, and f. the comparison of Ek of C. cylindricum cultured at different light intensities. Different letters (a, b, and c) represent significant differences among groups.
Figure 4. The comparison of qP of two Codium species cultured at different light intensities. a. The comparison of qP of C. fragile cultured at different light intensities, and b. the comparison of qP of C. cylindricum cultured at different light intensities.
Figure 5. The comparison of NPQ of two Codium species cultured at different light intensities. a. The comparison of NPQ of C. fragile cultured at different light intensities, and b. the comparison of NPQ of C. cylindricum cultured at different light intensities.
Figure 6. The pigments contents of two Codium species under different light intensities. a. Contents of chloroplast, and b. contents of carotenoids. Letter a represent no significant differences among groups (p>0.05, ANOVA, followed by Tukey’s multiple comparison test).
Figure 7. The MDA contents of two Codium species under different light intensities. Different letters (a and b) represent significant differences among groups (p<0.05, ANOVA, followed by Tukey's multiple comparison test).
Figure 8. The comparison of POD activity (a, letters a represent no significant differences among groups (p>0.05, ANOVA, followed by Tukey's multiple comparison test)) and T-AOC (b, different letters (a and b) represent significant differences among groups (p<0.05, ANOVA, followed by Tukey's multiple comparison test)) of two Codium species under different light intensities.
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