Effect of ACC Deaminase Producinging Rhizobium Strains on Growth of Wheat in Salinity Stress Conditions



Many plant growth promoting rhizobacteria (PGPR) contain 1-aminocyclopropane-1-carboxylate (ACC) deaminase enzyme that can convert the ACC, the immediate precursor of ethylene in plants, to ammonia and ?-ketobutyrate and cause a decrease in stress emanted ethylene. Wheat is a strategic crop and the people’s main staple in Iran. On the other hand salinity stress prevails in many soils as well as in many water resources in Iran. Therefore it is essential to find and offer the operational measures for increasing wheat yield in these conditions. In this greenhouse research work, the effect of two strains of Sinorhizobium meliloti namely KYA40 and KYA71 that contain ACC deaminase enzyme and S. meliloti KYA95 (non ACC deaminase enzyme containing, as control) on growth and on nutrients uptake of wheat in salinities of 7 and 10 dS.m-1 and SAR=10 mmol.l-1 in a complete factorial randomized block design was investigated. The results indicated that inoculation with strain KYA40 significantly increased the shoot length, shoot weight, root length, as well as Fe,Mn and Cu uptake. This strain increased shoot and root lengths by 13% and 34% respectively in 7 ds.m-1. Strain KYA40 increased the shoot dry weight by 9% in 10 dS.m-1 compared to non-inoculated. This strain increased Fe, Cu and Mn uptake by 47,45 and 37% (in 10 dS.m-1) respectively. Inoculation was not observed to have any significant effect on length and weight of ears, leaf area index, flag leaf lengh, flag leaf area, N, P, K and Zn uptake