Photosystem II 22kDa protein level ‐ a prerequisite for excess light‐inducible memory, cross‐tolerance to UV‐C and regulation of electrical signalling. (23rd January 2020)

• Record Type: Journal Article
• Authors: Górecka, Magdalena; Lewandowska, Maria; Dąbrowska‐Bronk, Joanna; Białasek, Maciej; Barczak‐Brzyżek, Anna; Kulasek, Milena; Mielecki, Jakub; Kozłowska‐Makulska, Anna; Gawroński, Piotr; Karpiński, Stanisław
• Is Part Of: Plant, cell and environment. Volume 43:Number 3(2020)
• Page Start: 649
• Page End: 661
• Publication Date: 2020-01-23
• Subjects: cell death -- chloroplast retrograde signalling -- electrical potential -- light memory and acclimation -- non‐photochemical quenching -- PsbS; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.13686
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: It is well known that PsbS is a key protein for the proper management of excessive energy in plants. Plants without PsbS cannot trigger non‐photochemical quenching, which is crucial for optimal photosynthesis under variable conditions. Our studies showed wild‐type plants had enhanced tolerance to UV‐C‐induced cell death (CD) upon induction of light memory by a blue or red light. However, npq4‐1 plants, which lack PsbS, as well as plants overexpressing this protein (oePsbS), responded differently. Untreated oePsbS appeared more tolerant to UV‐C exposure, whereas npq4‐1 was unable to adequately induce cross‐tolerance to UV‐C. Similarly, light memory induced by episodic blue or red light was differently deregulated in npq‐4 and oePsbS, as indicated by transcriptomic analyses, measurements of the trans‐thylakoid pH gradient, chlorophyll a fluorescence parameters, and measurements of foliar surface electrical potential. The mechanism of the foliar CD development seemed to be unaffected in the analysed plants and is associated with chloroplast breakdown. Our results suggest a novel, substantial role for PsbS as a regulator of chloroplast retrograde signalling for light memory, light acclimation, CD, and cross‐tolerance to UV radiation. Abstract : Plants without Photosystem II 22kDa protein (PsbS) cannot trigger non‐photochemical quenching (NPQ), which is crucial for optimal photosynthesis grow and development under variable light conditions. Here, we show that PsbS level influences not only the redox state of the plastoquinone pool, hormonal and electrical retrograde signals of light memory, but also regulates cell death and cross‐tolerance to UV‐C irradiation episodes. We suggest that the ability to memorize visible light episodes and subsequent induction of cross‐tolerance to UV‐C radiation is an old evolutionary phenomenon wherein PsbS and NPQ changes play an important role.