Combined effect of salinity and hypoxia in seedlings of two varieties of Panicum coloratum: morphology, root system architecture, oxidative damage and antioxidant response.

LIFSCHITZ M; TOMASSINO E; ZABALA J.M.; GRUMBERG, K; RAMOS J; TOMAS M

Annals of Applied Biology

Wiley

Lugar: Nueva Jersey; Año: 2021

The effect of the combination of salinity and waterlogging may be additive, oralternatively, more or less detrimental than effects of them separately. Our objectivewas to evaluate the effects of waterlogging, salinity and the combination of both onseedlings of Panicum coloratum, a subtropical forage grass. Seedlings of cultivarsKapivera INTA (KA) and Klein (KL) were exposed to treatments in a controlled hydroponicexperiment and several morphological and physiological variables evaluated.The effect of hypoxia was almost null when the plants were already in salinity. KAshowed lower reduction than KL in shoot biomass. Both varieties showed synergisticeffect of stresses, indicating that biomass production was less affected under thecombined treatment than predicted from them separately. Root length, tips, forksand volume were reduced by saline exposure, while no differences in root architecturewas noticeable between cultivars. Plants of KA increased leaf temperature insalinity. Nonenzymatic oxidative response and the activity of antioxidant enzymesincreased in saline conditions and were lower in KA than in KL. Oxidative damagewas equivalent between cultivars and among stress conditions. Proline content wascomparable to control in hypoxia but increased significantly in saline conditions, witha higher response in KL than in KA. Increases in Na+ (over 900%) and decreases inK+ (50%) tissue concentration in salinity occurred only in KA. In general, P. coloratumproved more tolerant to hypoxia than to salinity or their combination, KA being moretolerant than KL. Findings provide basis to deepen research into tolerancemechanisms.