Exploring ion homeostasis and mechanism of salinity tolerance in primary tritipyrum lines (Wheat× Thinopyrum bessarabicum) in the presence of salinity

Abstract

Due to lack of water resources in irrigated agriculture, genetically improving plants to abiotic stresses such as salinity is a necessity for food and feed production. In this respect, the new third man-made amphiploid cereal, tritipyrum (2n=6x=42, AABBE, is an example which is capable of tolerating a high level of NaCl. In order to determine the salinity tolerance mechanisms of this new cereal, an experiment was conducted using hydroponic technique. Ten tritipyrum lines and two wheat cultivars were tested under three levels of salinity (50, 100 and 200mM NaCl). The effect of salinity stress on Na + and K + concentration of leaf, shoot and root, proline and chlorophyll content were measured at 50% ear emergence and their grain yield plant -1 was evaluated at physiological maturity. Leaf Na + concentration in tritipyrum lines increased with increasing salinity while K + concentration did not show any especial pattern. The chlorophyll and proline content in tritipyrum lines were higher than that of wheat cultivars. Despite the high sodium concentration in tritipyrum lines in comparison with wheat, the grain yield of tritipyrum lines were less affected than that of wheat. There was also a negative correlation between proline content and grain yield plant -1 in tritipyrum lines. It can be concluded that mechanisms such as higher Na + uptake along with appropriate ion compartmentation could be used by tritipyrum lines to combat with salt stress like some halophytes and it can make tritipyrum lines suitable for planting in saline soils and improving the salinity tolerance of wheat. Keywords:Halophytic wild ancestors, Proline, Salt tolerance mechanism, Tritipyrum. Abbreviations: LNa_ leaf sodium concentration; LK_ leaf potassium concentration; LK:Na or L K + /Na + _ leaf potassium to sodium ratio; SN_ stem sodium concentration; SK_ stem potassium concentration; SK:Na_ stem potassium to sodium ratio; RN_ root sodium concentration; RK_ root potassium concentration; RK:Na_ root potassium to sodium ratio; Chl a_chlorophyll a concentration; Chl b_ chlorophyll b concentration; Chl a/b_ chlorophyll a to chlorophyll b ratio; T Chl_ total chlorophyll; GY_ grain yield plant

Biochemical mechanisms of salinity tolerance in new promising salt tolerant cereal, tritipyrum (TriticumDurum× Thinopyrum Bessarabicum)

“…It was reported that tritipyrum lines had different salinity resistance thresholds (Kamyab et al, 2016). Generally, the results revealed different used mechanisms and responses to salinity stress of tritipyrum lines in comparison with wheat cultivar Bam.…”

“…Bam (a salt tolerant wheat cultivar) were used based on findings of other studies carried out on their salt tolerance (Kamyab et al, 2016) (Table 2). Seeds with similar shape and weight were sown in seedling growing trays (7cm deep cells with a diameter of 2cm), the trays were filled with sand, soil and manure (2: 1: 1).…”

Biochemical and Molecular Mechanism of Salinity Stress Tolerance in Plants

“…Maintaining the ion homeostasis is crucial for plant growth under normal and salinity stressed condition (Kamyab et al, 2016). At high salt concentration, the Na + ion entered in the cytoplasm is compartmentalized in to vacuole by Na + /H + antiporter.…”

Tritipyrum (Triticum durum × Thinopyrum bessarabicum) might be able to provide an economic and stable solution against the soil salinity problem

“…Therefore, recognizing the most salt-tolerant genotypes at each stage, understanding the effects of salinity on different developmental growth stages of plants, and identifying a collection of credible criteria related to salinity resistance are necessary for developing management strategies and facilitating breeding programs in order to reduce the harmful effects of salinity, retain plant performance at a satisfactory level, and improve salt tolerance of plants (Zeng et al, 2002;Zeng and Shannon, 2000). Few studies have focused on the salinity tolerance of tritipyrum lines in hydroculture experiments (Kamyab et al, 2016). However, field trail is essential to confirm the potential of these hybrids for agricultural use and to answer the query of whether tritipyrum lines can produce commodious yield in the field condition during salinity stress.…”