Resumen:
The cultivated area of soybean has increased worldwide in past decades, including regions
with saline soils, strongly decreasing growth and productivity. The use of amino acids (AAs) as
buffering compounds against stressful conditions can be a useful strategy to mitigate salt stress
in these regions. This study aimed to evaluate the effects of foliar application of AA mixtures on
the growth, physiology, and biochemistry traits of salt-stressed soybean plants. A pot experiment
was designed as a factorial scheme (4 3) in a randomized complete design (RCD). Treatments
consisted of four concentrations of AA mixtures of a non-VA application, 0.4 mL L��������1, 0.8 mL L��������1,
and 1.2 mL L��������1 (VIUSID Agro® (VA) source), which were combined with non-salt stressed and saltstressed
groups (50 and 100 mmol L��������1 NaCl), to analyze improvement in growth and potassium (K+)
accumulation, maintenance of relative water content (RWC), net photosynthesis rate (A), transpiration
(E), stomatal conductance (gs), and chlorophyll content, and increase of proline accumulation and
water use efficiency (iWUE). Moderate and high salinity induced a notable increase in oxidative and
ionic biomarkers, coupled with higher Malondialdehyde (MDA) concentration and Na+ accumulation.
Alternatively, soybean growth, K+ accumulation, and physiological and biochemical parameters
were decreased under salinity. Foliar spraying of AAs drastically increased osmolyte accumulation
associated with sustained iWUE and RWC, increased proline accumulation, and improved A, E, gs,
and chlorophyll content. Greater outcomes were achieved with the foliar spraying of amino acids
at 1.2 mL L��������1. Collectively, foliar application of AA mixtures plays an important role in salt stress
remediation by modifying important physiological and biochemical processes, thereby resulting in a
higher growth of soybean plants.
