No stress memory pattern was detected in sugar maple and white spruce seedlings subjected to experimental droughts

Abstract

An increase in the frequency and magnitude of drought events threatens the health of forests and the economic, ecological, and societal services they provide. It has been widely demonstrated that trees undergoing a succession of stresses may accumulate lesions that in turn lead to a decrease in their vigor and eventually to death. However, recent studies have shown that a nonlethal stress should also initiate a stress memory, which triggers a faster and stronger plant defensive response when a new stress occurs. Although this mechanism is well understood in many herbaceous plants, a better understanding in trees is needed. The aim of our study was to explore the capacity of two forest tree species to develop a stress memory. A greenhouse experiment was conducted to evaluate the tree seedlings' vigor after one or two consecutive droughts separate from a rehydration period during the same growing season. No stress memory pattern was observed for the two tree species as, on the contrary, we even observed a stress accumulation pattern in sugar maple. It remains possible that some individuals in our study developed stress memory, but that we were not able to detect it. The fine‐tuning of experimental parameters and the conducting of longitudinal studies would be helpful to detect individual capacity in stress memory activation.

Transcriptome profiling, physiological, and biochemical analyses provide new insights towards drought stress response in sugar maple (Acer saccharum Marshall) saplings

“…Perennial trees signal their water deficit with several symptoms. The most common alterations in appearance are lighter green to yellow-green foliage, scorches around the leaf margins, leaf wilting, necrosis, and drooping ( Li et al., 2015 ; Ball, 2021 ; Ribeyre et al., 2022 ). We observed similar symptoms in sugar maple upon drought stress in the present study; severe symptoms occurred with increased drought stress time ( Figure S2 ).…”

From stressor to protector, UV-induced abiotic stress resistance

“…It was hypothesised that the dramatic decrease in RH, caused by transferring plantlets to growth-room conditions, is responsible for the development of abiotic stress in the in vitro raised plantlets, and the subsequent development of necrotic areas. Indeed, drought stress is often associated with formation of necrotic spots [ 32 ]. Moreover, by raising the RH to 90% necrosis was avoided.…”