Ion homeostasis, osmoregulation, and physiological changes in the roots and leaves of pistachio rootstocks in response to salinity

Abstract

Pistachio, one of the important tree nuts, is cultivated in arid and semi-arid regions where salinity is the most common abiotic stress encountered by this tree. However, the mechanisms underlying salinity tolerance in this plant are not well understood. In the present study, five 1-year-old pistachio rootstocks (namely Akbari, Badami, Ghazvini, Kale-Ghouchi, and UCB-1) were treated with four saline water regimes (control, 8, 12, and 16 dS m) for 100 days. At high salinity level, all rootstocks showed decreased relative water content (RWC), total chlorophyll content (TCHC), and carotenoids in the leaf, while ascorbic acid (AsA) and total soluble proteins (TSP) were reduced in both leaf and root organs. In addition, the total phenolic compounds (TPC), proline, glycine betaine, total soluble carbohydrate (TSC), and HO content increased under salinity stress in all studied rootstocks. Three different ion exclusion strategies were observed in the studied rootstocks: (i) Na exclusion in UCB-1, because most of its Na is retained in the roots; (ii) Cl exclusion in Badami, in which most of its Cl remained in the roots; and (iii) similar concentrations of Na and Cl were observed in the leaves and roots of Ghazvini, Akbari, and Kale-Ghouchi. Transport capacity (ST value) of K over Na from the roots to the leaves was more observable in UCB-1 and Ghazvini. Overall, the root system cooperated more effectively in UCB-1 and Badami for retaining and detoxifying an excessive amount of Na and Cl. The results presented here provide important inputs to better understand the salt tolerance mechanism in a tree species for developing more salt-tolerant genotypes. Based on the results obtained here, the studied rootstocks from tolerant to susceptible are arranged as follows: UCB-1 > Badami > Ghazvini > Kale-Ghouchi > Akbari.

Targeting Glycinebetaine for Abiotic Stress Tolerance in Crop Plants: Physiological Mechanism, Molecular Interaction and Signaling

“…This finding opens a new avenue, where GB is associated with symbiosis to regulate abiotic stress tolerance in plants. Glycinebetaine, Pro, total phenolics and soluble carbohydrate content sharply increased in the rootstock and leaves of pistachio plants on exposure to salt stress [87]. The accumulation of the osmolytes also facilitated exclusion of Na + and Clin the rootstocks of the assayed cultivars grown under saline conditions [87].…”

Molecular Characterization of a Tonoplast Na⁺/H⁺ Antiporter from <em>Iris Lactea</em>

“…Salt stress caused the inhibition of photosynthesis-related pigments in plants, and further impacted on the photosynthesis efficiency [45,46]. Our data showed that the chlorophyll level in transgenic tobacco plants is always higher than WT plants subjected to salt stress ( Figure 6A).…”

Correlation of Heat and Cold Tolerance in Iranian Tall Fescue Ecotypes with Reactive Oxygen Species Scavenging and Osmotic Adjustment

“…Compatible cytosolutes including proline, TNC, soluble sugars and glycine betaine can reduce the cell's osmotic potential under dehydration (Sheikh-Mohamadi et al, 2017d). Proline is an important compatible osmolyte and a scavenger of ROS in plants (Akbari et al, 2018). During the experiment, proline content remained constant at optimal temperatures in all ecotypes (Fig.…”