Evidence of drought memory in Dipteryx alata indicates differential acclimation of plants to savanna conditions

Abstract

The remarkable phytogeographic characteristics of the Brazilian savanna (Cerrado) resulted in a vegetation domain composed of plants with high structural and functional diversity to tolerate climate extremes. Here we used a key Cerrado species (Dipteryx alata) to evaluate if species of this domain present a mechanism of stress memory, responding more quickly and efficiently when exposed to recurrent drought episodes. The exposure of D. alata seedlings to drought resulted in several changes, mainly in physiological and biochemical traits, and these changes differed substantially when the water deficit was imposed as an isolated event or when the plants were subjected to drought cycles, suggesting the existence of a drought memory mechanism. Plants submitted to recurrent drought events were able to maintain essential processes for plant survival when compared to those submitted to drought for the first time. This differential acclimation to drought was the result of orchestrated changes in several metabolic pathways, involving differential carbon allocation for defense responses and the reprogramming and coordination of primary, secondary and antioxidant metabolism. The stress memory in D. alata is probably linked the evolutionary history of the species and reflects the environment in which it evolved.

Drought Stress Study on Nicotiana tabacum L., “Baladi”, an In Vitro Experimental Model

“…In this study all 18 tobacco clones have been investigated for their ability to face the stress of acclimatization. This process is named today drought memory and it is in line with other recent studies (osmotic stress) [56], for ABA effect [57]. Scientific results and hypothesis are already supporting this concept [58].…”

Differential Response of Two Tomato Genotypes, Wild Type cv. Ailsa Craig and Its ABA-Deficient Mutant flacca to Short-Termed Drought Cycles

“…Similarly, Leufen and co-workers [80] obtained the same trend in proline accumulation in sugar beet exposed to recurrent drought. The opposite was observed in coffee and the baru tree with the largest increase in proline observed after the 3rd drought cycle [9,81]. While in WT Ψ decreased to the same extent in all three cycles, in flacca, the reduction in Ψ was significantly higher in the 2nd and 3rd drought cycles.…”

Drought legacies and ecosystem responses to subsequent drought

“…The observed higher water retention and concurrent higher stomatal conductance can maintain plant functioning during subsequent droughts . Furthermore, an adaptation toward higher photosynthetic rate was observed under recurrent drought and during its recovery (Alves et al, 2020).…”