Rethinking drought memory in crops: A call for improved experimental design

The concept of stress memory has attracted increasing attention due to its potential implications for crop improvement. However, empirical support for the existence and benefits of this phenomenon, particularly within the context of intragenerational stress memory, remains scarce. In this review article, we critically examined the current understanding of drought memory, posing critical questions such as: Does it truly exist? How long does it last? Is it beneficial for crops? Besides the fact that these questions cannot be fully answered with the currently available evidence, our analysis reveals a significant methodological deficiency in many published experiments. Specifically, a common experimental design compares plants subjected to a single water deficit episode against those experiencing two, without adequately considering confounding variables such as the reduced size and water consumption of primed plants. We underscore this fundamental flaw to promote the use of more rigorous experimental protocols and propose different strategies to overcome this issue. Future research employing these revised methods will be better positioned to elucidate whether stress memory provides a genuine adaptive benefit and to determine the endurance of this protective effect.