Molecular and physiological analysis of drought stress in Ilex paraguariensis St. Hil. (yerba mate): state of the arts

SANSBERRO, P.

Mar del Plata

Conferencia; XV Asamblea Latinoamericana de Fisiología Vegetal y XXX Reunión Argentina de Fisiología Vegetal.; 2014

ASAFV

Primary production of yerba mate has several drawbacks that require attention in order to preserve the economic and social sustainability of the producing region. Among them, drought is the most important limiting factor for crop production since plants are frequently exposed to water deficit during the summer season, which leads to leaf abscission and yield reduction.Initially, two cultivars growing in the field with contrasting behavior respect to gas exchange were selected. Subsequently, to determine the physiological basis of drought tolerance and identify drought long-term responsive genes, a 35-day experiment under controlled environmental conditions was developed by inducing a gradual decrease of soil moisture.The physiological analysis indicated that tolerant genotype uses stomatal closure, as a strategic tool to avoid wilting at an early stage of dehydration. Subsequently, as the leaf water potential decreases due to the intensification of stress, plant reacts making osmotic adjustment to sustain metabolic activity and enable rapid recovery of photosynthetic activity after re-watering. Sequence analysis revealed that activated genes were mostly involved in signal transduction, transcription, photosynthesis, and respiration while down-regulated genes were involved in metabolism, protection, and plant defense against microorganisms. The possible role of these genes in plant stress-response will be discussed.