'Ecological photobiology' session of the Russian Photobiology Society 9 Congress (Shepsi, September 12-19, 2021).

'Ecological photobiology' session of the Russian Photobiology Society 9th Congress was devoted to a wide range of problems related to the assessment of the environmental state by photobiological methods and included oral presentations and a poster session. A short survey of these presentations is given.

Blue light alters miR167 expression and microRNA-targeted auxin response factor genes in Arabidopsis thaliana plants.

The effect of blue LED (450 nm) on the photomorphogenesis of Arabidopsis thaliana Col-0 plants and the transcript levels of several genes, including miRNAs, photoreceptors and auxin response factors (ARF) was investigated. It was observed that blue light accelerated the generative development, reduced the rosette leaf number, significantly reduced the leaf area, dry biomass and led to the disruption of conductive tissue formation. The blue LED differentially influenced the transcript levels of several phytochromes (PHY a, b, c, d, and e), cryptochromes (CRY 1 and 2) and phototropins (PHOT 1 and 2).

Optical properties of rhodoxanthin accumulated in Aloe arborescens Mill. leaves under high-light stress with special reference to its photoprotective function.

In Aloe arborescens Mill. leaves, strong sunlight or its combination with drought induces the accumulation of the red keto-carotenoid, rhodoxanthin. Simultaneously, the transformation of chloroplasts into chromoplasts accompanied by degradation of thylakoid membranes and formation of plastoglobuli, large in size and number, takes place.