Salt Tolerance in the Halophyte Suaeda maritima L. Dum.—the Effect of Oxygen Supply and Culture Medium on Growth

Abstract

Suaeda maritima is an annual species that grows in salt marshes and tolerates not only salt but also flooding, although plants are smaller at lower than at higher elevations of salt marshes. We investigated whether adventitious roots play a role in tolerance to flooding and how flooding affects ion accumulation in the shoots, a determinant of growth in this species. We examined the response of plants grown in Stout and Arnon culture solution to different periods of flooding at different salinities and verified our results with plants grown in other culture solutions (Hoagland and Yoshida). We measured growth, photosynthesis and estimated stomatal frequency as well as the accumulation of Na+, Ca2+, Mg2+ and K+: plants grew and photosynthesised optimally in 200-mM Na+ (in Stout and Arnon solution), but the optimal concentration for growth increased to 450 mM when in Yoshida solution. Flooding always decreased growth, but had little effect on Na+ concentrations. Although plants produced adventitious roots, their mass decreased rather than increased with flooding. The decrease in production of adventitious roots under flooded conditions suggested that they were not important in the tolerance of this species to submergence—an unusual response compared with the general response of flooding-tolerant plants.

Differentially Expressed Long-Term Salinity Responsive Sequences in Halophyte Suaeda maritima (L.) Dumort

“…Suaeda maritima (L.) Dumort is an herbaceous, facultative, annual halophyte with succulent leaves that grows up to 30 cm in height that is native to saline soils of arid and semiarid regions. This species is a self-pollinated bisexual dicot of the family Chenopodiaceae (now included in the family Amaranthaceae) with 2n = 36 chromosomes that produces reddish brown seeds (Sahu & Shaw, 2009;Alhdad & Flowers, 2020;Certain et al, 2021). It exhibits high resistance to alkali stresses and grows well with salt content even without salt glands or bladders on its leaves to modulate their tissue ion concentration.…”