A regulatory role of autophagy for resetting the memory of heat stress in plants. (1st October 2018)

• Record Type: Journal Article
• Authors: Sedaghatmehr, Mastoureh; Thirumalaikumar, Venkatesh P.; Kamranfar, Iman; Marmagne, Anne; Masclaux‐Daubresse, Celine; Balazadeh, Salma
• Is Part Of: Plant, cell and environment. Volume 42:Number 3(2019)
• Page Start: 1054
• Page End: 1064
• Publication Date: 2018-10-01
• Subjects: Arabidopsis -- heat shock proteins -- priming -- resetting; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.13426
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: As sessile life forms, plants are repeatedly confronted with adverse environmental conditions, which can impair development, growth, and reproduction. During evolution, plants have established mechanisms to orchestrate the delicate balance between growth and stress tolerance, to reset cellular biochemistry once stress vanishes, or to keep a molecular memory, which enables survival of a harsher stress that may arise later. Although there are several examples of memory in diverse plants species, the molecular machinery underlying the formation, duration, and resetting of stress memories is largely unknown so far. We report here that autophagy, a central self‐degradative process, assists in resetting cellular memory of heat stress (HS) in Arabidopsis thaliana . Autophagy is induced by thermopriming (moderate HS) and, intriguingly, remains high long after stress termination. We demonstrate that autophagy mediates the specific degradation of heat shock proteins at later stages of the thermorecovery phase leading to the accumulation of protein aggregates after the second HS and a compromised heat tolerance. Autophagy mutants retain heat shock proteins longer than wild type and concomitantly display improved thermomemory. Our findings reveal a novel regulatory mechanism for HS memory in plants. Abstract : Plants have a "memory" for a previous heat stress. Sedaghatmehr et al. report a previously undiscovered role of autophagy for resetting the memory of heat stress (HS) via the specific degradation of different classes of heat shock proteins (HSPs) in Arabidopsis. This leads to a reduction in thermomemory capacity (increased forgetfulness) and subsequently a weaker response, evidenced by an accumulation of aggregated proteins, upon exposure to a post‐recovery severe HS. Autophagy deficiency favors higher HSP levels at the later time points thereby enhancing thermomemory.