Induced in vitro adaptation for salt tolerance in date palm (Phoenix dactylifera L.) cultivar Khalas

Abstract

Background: Soil salinity causes huge economic losses to agriculture productivity in arid and semiarid areas worldwide. The affected plants face disturbances in osmotic adjustment, nutrient transport, ionic toxicity and reduced photosynthesis. Conventional breeding approaches produce little success in combating various stresses in plants. However, non-conventional approaches, such as in vitro tissue culturing, produce genetic variability in the development of salt-tolerant plants, particularly in woody trees. Results: Embryogenic callus cultures of the date palm cultivar Khalas were subjected to various salt levels ranging from 0 to 300 mM in eight subcultures. The regenerants obtained from the salt-treated cultures were regenerated and evaluated using the same concentration of NaCl with which the calli were treated. All the salt-adapted (SA) regenerants showed improved growth characteristics, physiological performance, ion concentrations and K + /Na + ratios than the salt non-adapted (SNA) regenerants and the control. Regression between the leaf Na + concentration and net photosynthesis revealed an inverse nonlinear correlation in the SNA regenerants. Leaf K + contents and stomatal conductance showed a strong linear relationship in SA regenerants compared with the inverse linear correlation, and a very poor coefficient of determination in SNA regenerants. The genetic fidelity of the selected SA regenerants was also tested using 36 random amplified polymorphic DNA (RAPD) primers, of which 26 produced scorable bands. The primers generated 1-10 bands, with an average of 5.4 bands per RAPD primer; there was no variation between SA regenerants and the negative control. Conclusion: This is the first report of the variants generated from salt-stressed cultures and their potential adaptation to salinity in date palm cv. Khalas. The massive production of salt stress-adapted date palm plants may be much easier using the salt adaptation approach. Such plants can perform better during exposure to salt stress compared to the non-treated date palm plants.

Oxidative damage, antioxidant mechanism and gene expression in tomato responding to salinity stress under in vitro conditions and application of iron and zinc oxide nanoparticles on callus induction and plant regeneration

“…The application of nano-micronutrients has been reported to reduce the harmful effects of salinity on plants (for example, by improving water relations, photosynthesis and nutrition and regulating antioxidant defenses and increasing osmotic and amino acid protection levels [ 76 ]. In vitro cultivation provides a controlled and homogenous environment for analysis of physiological processes of plants, especially at the cellular level under various treatments of chemicals [ 77 ]. Callus induction increased the dry matter percentage in presence of NaCl concentration and decreased RGR in all tomato cultivars [ 27 ].…”

Plant Group II LEA Proteins: Intrinsically Disordered Structure for Multiple Functions in Response to Environmental Stresses

“…As a desert plant with a native tolerance to wide range of abiotic stresses, the date palm may act as a treasure store of novel genetic resources that can be exploited for abiotic stress tolerance [160]. Although a number of physiological, molecular, and biochemical analyses of stress-related genes in date palms have been documented, research on the functional properties of date palm group II LEA genes is still scarce [156,157,161]. The lack of analyses of DHNs in date palm has been associated to its many varieties, of which only a few are dominant and actively cultivated [162].…”

Agronomical, Physiological and Biochemical Characterization of In Vitro Selected Eggplant Somaclonal Variants under NaCl Stress

“…In vitro culture, as an induced somaclonal variation, proved to be a promising and effective method to obtain salt-tolerant genotypes. The selection of salt-tolerant cell lines has been reported for numerous crops [6,7]. However, the results are not always predictable.…”