Synergistic effect of arbuscular mycorrhizal fungi and spermine on amelioration of salinity stress of wheat (Triticum aestivum L. cv. gimiza 9).

The previous studies about the interactive effect of spermine (Spm) and arbuscular mycorrhizal (AM) fungi on physiological aspects and root colonization in wheat under salinity stress are insufficient. In this regard, a pot experiment was conducted to investigate the effect of Glomus mosseae (Nicol.& Gred.) Gred. and Trappe and Spm on growth and some physiological aspects of wheat (Triticum aestivumL. cv. gimiza 9) plants grown under three levels of saline underground water (1.2 dsm -1 “control”, 6.09 dsm -1 and 10.63 dsm 1 ). Salinity stress significantly decreased shoot mass, total and specific leaf area, photosynthetic pigments, spermine and spermidine concentration of wheat plants in comparison with control plants and this effect was more pronounced with the highest level of salinity. The application of mycorrhizal inoculations or spermine mitigated the adverse effects of salinity stress on shoot biomass and specific leaf area of wheat when compared with non-mycorrhizal ones. These treatments appeared to enhance photosynthetic pigments, proline, protein, spermine and spermidine, and lowered putrescine contents of the salt-stressed plants. Interestingly, the dual treatments with AM fungi and spermineh have been considered as additional positive effect on growth, salt tolerance and mycorrhizal root colonization in wheat plants. This effect was accompanied with more enhancements in chlorophylls content at both salinity levels, and proline and protein content at the highest salinity level only. Furthermore, this combination treatment, AM fungi + Spm, caused more reduction in putrescine content than AM inoculation and spermine treatments each alone. A negative correlation appeared between the salinity tolerance index and putrescine level in the used cultivar at low and high salinity. The dual application of AM fungi with Spm could be important for salt alleviation in wheat plants growing in saline soils.