Anatomical changes induced by salinity stress in Salicornia freitagii (Amaranthaceae)

Abstract

A salt-tolerant population of Salicornia freitagii Yaprak and Yurdakulol (naturally adapted) from saline soils of Bahşili village, Sungurlu, Ç orum, Turkey, was evaluated for root and succulent stem modifications. Salttolerant populations from low (2.3 dS m-1), medium (20.7 dS m-1) and highly (46.3 dS m-1) saline soils were collected for comparisons. Decreased parenchyma in roots is critical for enhancing water loss. However, the thickness of parenchyma in roots of S. freitagii collected from the edge of the stream was not more affected by the increase in salinity levels. Stem anatomical characters as thickness, length and width of water-storing tissue significantly increased in highly saline environments. The thickness of xylem and the diameter of the vessels decreased at higher salinity. There was an increase in the diameter of pith in stem with increasing salt levels. Additionally, it was observed that stomatal index was considerably reduced under high salinity. Our results report root and stem anatomical features of S. freitagii resulting from adaptation to salinity stress.

Anatomical Changes Induced by Salinity Stress in Root and Stem of Two Acacia Species (A. Karroo and A. Saligna)

“…These changes in anatomical dimensions can be considered as an adaptive mechanism of A. saligna in order to maintain a regular water movement in aerial parts of plants, especially under saline conditions (Polle and Chen, 2015). Unlike A. saligna, the plants of A. karroo of this study and the case of many plants have undergone a decrease in the stem pith under salt regime: Leptochloa fusca (Ola et al, 2012); Leucaena leucocephala (El-LAmey, 2015); Phaseolus vulgaris (Bargaz et al, 2016); Salicornia freitagii (Akcin et al, 2017). These same authors have pointed out that this reduction due to salinity is indeed another strategy of salinity and water-stress tolerance.…”

“…As salt concentration increases, a decrease or increase in the crosssectional area of the stems was observed in A. auriculiformis (Rahman et al, 2017) and A. ampliceps (Theerawitaya et al, 2015). Akcin et al (2017) have associated the stem succulence with the adaptation mechanisms to saline conditions in a halophytic species Salicornia freitagii. According to Figure 3 and Table 1, the anatomy of the stems has been modified when applying various doses of salt water.…”

Anatomical Adaptations of Halophytes Within the Southern Pannonian Plain Region

“…In general, anatomical adaptations to salt stress include increased cell volume due to which leaf thickness increases, whereas vessel diameter decreases (Akcin et al 2015(Akcin et al , 2017Rancic et al 2019). Formation of narrower vessels improves water-use capacity and reduces risk of xylem embolism and cavitation in saline habitats (Polle and Chen 2015).…”

“…includes leafless species with succulent stems, which have developed several adaptations to salinity and drought, the most common of which are sunken stomata, vascular bundles surrounded by lignified fibers, anomalous secondary thickening producing significant amount of lignified tissue, scattered tracheoidioblasts, welldeveloped water storage parenchyma, suberified cells near stem pericycle and strongly developed root endodermis (Keshavarzi and Zare 2006;Milic et al 2011). In Salicornia freitagii Yaprak and Yurdakulol, salinity stress induces xylem tissue thickness and root and stem vessel diameter reduction, along with increased stem thickness and greater stem water-storing tissue size, formation of tracheoidioblasts and successive cambia, and decreased leaf stomatal density (Akcin et al 2017). Grigore et al (2012) recorded several adaptations in Romanian halophytic species, including succulence, successive cambia formation, salt secretory structures, Kranz leaf anatomy, and bulliform cells.…”

“…To be able to absorb soil water and transport it to the aboveground organs, halophytes develop different mechanisms to modify osmotic potential of their tissues (Akcin et al 2017). They generate lower cell water potential, which should decrease acropetally in the xylem, to maintain water uptake under osmotic stress and to extract water from the saline soil (Safiallah et al 2017).…”