Stress induced modifications in photosystem II electron transport, oxidative status, and expression pattern of acc D and rbc L genes in an oleaginous microalga Desmodesmus sp.

The study aimed at understanding the biochemical and molecular level modifications in Desmodesmus sp. under
lipid inducing stress conditions. The low-temperature (5 °C) incubation and nitrogen starvation reduced the PS II
electron transport in microalga with a maximum reduction of 50–57% in ET0/ABS values. The PS II electron
transport recovered in UV treated cultures after an initial reduction of 87–93% in ET0/ABS values. A 2.7–4.4 fold
increase in ROS and MDA levels was observed under low-temperature incubation, and nitrogen starvation. The
UV treatment caused 1.3–2.4 fold higher ROS and MDA levels than control. The low-temperature incubated,
nitrogen starved, and UV treated cultures showed 2.4–4 fold higher acc D gene expression. A higher rbc L gene
expression was observed under low-temperature stress. The study showed modifications in PS II electron
transport, oxidative status, and expression of acc D and rbc L genes under stress conditions.