Come Hell or High Water: Breeding the Profile of Eucalyptus Tolerance to Abiotic Stress Focusing Water Deficit

Metabolic, Nutritional and Morphophysiological Behavior of Eucalypt Genotypes Differing in Dieback Resistance in Field When Submitted to PEG-Induced Water Deficit

“…Surprisingly, and against our expectations, there were no significant differences in transpiration rate, WUE, WUE i , starch and mono-and disaccharides between SuzT and SuzS, in addition to a greater net photosynthesis for SuzS. We hypothesize that other strategies that were not screened in the present report may be contributing to a more tolerant phenotype [17]. Unpublished data of an ulterior experiment of our group point to different concentration of α and β glucose, among other metabolites, that could be associated with more and less tolerant eucalypt genotypes submitted to water deficit conditions.…”

“…Despite similar root dry matter among the evaluated genotypes and treatments, there were significant differences in the carbon allocation, even though interactions between genotype and water deficit treatment were absent. This reinforces the need for a richer evaluation of root traits delineated in Picoli et al's [17] review that have drawn attention to root architecture, growth restriction, distribution and carbon allocation and that can provide further information to the water deficit resistance in eucalypts.…”

“…This analysis corroborates the previous results [9,28], showing that, when subjected to water deficit, the SuzMT and SuzTP genotypes behave similarly to SuzT, while SuzS differs from them. Despite data from control and water deficit treatments being analyzed together, this may have caused noise [17,33] that will also have implications on the evaluation and response of each characteristic evaluated.…”

“…Plants are expected to have different metabolic, morphological, growth and nutritional responses when submitted to stress conditions [1,10,17,18,20,21,24,25]. These stress responses share common pathways, but it is also expected that the characteristics in a tolerant individual will contribute to this genotype to be better adapted to deal with this stressful factor.…”

“…In addition, water deficit can influence the nutritional content, boron absorption, nitrogen and carbon metabolism and osmotic adjustment [14][15][16]. Water deficit in its turn is reported and evaluated from seedling to more than 20-year-old plants, which is a wide window of time to trigger any stress response [17]. Water deficit causes a series of physiological stresses that can trigger the appearance of dieback [1,18]; further, there are reports that link eucalypt dieback to some essential minerals such as boron [15] and manganese [3].…”