TITLE:
Implication of Ions and Organic Solutes Accumulation in Amaranth (Amaranthus cruentus L.) Salinity Resistance
AUTHORS:
Agapit Wouyou, Hermann Prodjinoto, Ahissou Séraphin Zanklan, Brigitte Vanpee, Stanley Lutts, Christophe Bernard Gandonou
KEYWORDS:
Growth, Ions Concentration, Osmolytes Accumulation, Amaranthus cruentus, Salt-Resistance Mechanism
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.10 No.12,
December
31,
2019
ABSTRACT: Salinity is one of the major environmental
constraints limiting agricultural productivity in the world. The effects of
salt stress on growth, ions and organic
solutes accumulation were investigated in two amaranth (Amaranthus cruentus) cultivars: Rouge (salt-resistant) and Locale (salt-sensitive). Young plants of
these cultivars were exposed, in hydroponic system, to three concentrations of NaCl: 0, 30 and 90 mM. Growth parameters,
ions, free proline and soluble sugars
concentrations were determined after 2 weeks of stress. NaCl effect resulted in
plant growth reduction in both cultivars but plants of cultivar Rouge were less affected compared to
that of cv. Locale. Na+,
proline and soluble sugars concentrations increased significantly in leaves and
roots under salinity while K+, Ca2+ and Mg2+ concentrations decreased in
both cultivars. Proline and soluble sugars increased significantly in leaves
and roots of cultivar Locale whereas
in cultivar Rouge, proline increase
was significant only in roots and soluble sugars increase was significant only
in leaves. The highest increase of Na+ concentration occurred in
leaves of cv. Rouge coupled with the
lowest reduction in K+ concentration. The highest increase of
proline occurred in leaves of cultivar Locale whereas the highest increase of soluble sugars was observed in leaves of cultivar Rouge. The reduction of the Ca2+ concentration under salt stress was more accentuated in both leaves and roots
of cultivar Rouge than cultivar Locale while cv. Rouge maintained
higher content in Mg2+ either in leaves or in roots in the presence
of NaCl than cultivar Locale. These
results suggest an implication of Na+, K+ and Mg2+ in salt resistance in these
cultivars and that soluble sugars may play an important role in salt-resistance
in Amaranthus cruentus. However,
proline appears as a symptom of injury in stressed plants rather than an
indicator of resistance.