The effect of drought stress on physiological responses of maize plants originating from seeds of different ages

Drought is one of the main consequences of climate change that negatively affects plant growth and development, which in turn leads to a reduction in yield. The objective of this study was to investigate the effects of the physiological responses to the drought stress of maize plants (population IP3722), obtained from seeds of different ages (originating from 2012. and 2016) and different previous experience (the seeds formed in 2012. were more exposed to drought than in 2016.). Two populations responded to drought treatment by a significant decrease of shoot fresh and dry weight, this was followed with decrease leaf area and transpiration rate. Drought treatments enabled induction and differentiation of chemical signals of drought (abscisic acid-ABA and xylem pH) and hydraulic signals (leaf water potential), and monitoring of their activity on stomatal conductance. The data showed that hydraulic signals have the same impact on stomatal reactions in the D2012 and D2016 treatments. They also indicated that the chemical signal of ABA works toward stomatal closure, but that the effect depends on whether it originates from the leaf or the root. Leaf-originating ABA had more effect on the closure of D2012 stomata, while root-originating ABA and pH was more active in the D2016.