INVESTIGADORES
MENENDEZ Ana Bernardina
artículos
Título:
1. Comparative study of alkaline, saline and mixed saline-alkaline stresses, with regard to their effects on growth, nutrient accumulation and root morphology of Lotus tenuis
Autor/es:
PAZ, R; ROCCO R; REINOSO, H; MENÉNDEZ, A; FERNANDO PIECKENSTEIN; RUIZ, O
Revista:
JOURNAL OF PLANT GROWTH REGULATION
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012 vol. 31 p. 448 - 459
ISSN:
0721-7595
Resumen:
Both saline and alkaline conditions frequently
coexist in nature; however, little is known about the effects
of alkaline and salt?alkaline stresses on plants. We performed
pot experiments with four treatments, control
without salt addition and three stress conditions?neutral,
alkaline, and mixed salt?alkaline?to determine their
effects on growth, nutrient accumulation and root architecture
in the glycophytic species Lotus tenuis. Neutral and
alkaline salts produced a similar detrimental effect on
L. tenuis growth, whereas the effect of their combination
was synergistic. Neutral salt addition, alone or mixed with
NaHCO3, led to significant leaf Na? build up and reduced
K? concentration. In contrast, in plants treated with
NaHCO3 only, Na? levels and the Na?/K? ratio remained
relatively unchanged. Proline accumulation was not
affected by the high pH in the absence of NaCl, but it was
raised by the neutral salt and mixed treatments. The total
root length was reduced by the addition of NaCl alone,
whereas it was not affected by alkalinity, regardless of the
presence of NaCl. The topological trend showed that
alkalinity alone or mixed with NaCl turned the root more
herringbone compared with control roots, whereas no significant
change in this index was observed in the treatment
with the neutral salt only. The pattern of morphological
changes in L. tenuis root architecture after the alkaline
treatment (in the absence of NaCl) was similar to that
found in the mixed salt?alkaline treatment and different
from that observed in neutral salt. A unique root morphological
response to the mixed salt?alkaline stress was the
reduction in the ratio between xylem vessels and root
cross-sectional areas.