جستجوی مقالات مرتبط با کلیدواژه "دآمیناز" در نشریات گروه "زراعت"

In this study، the ability of 32 rhizobium strains (26 strain of Sinorhizobium meliloti (SM))، 4 strains of Rhizobium leguminosarum biovar phaseoli (Rlp) and 2 salt tolerance strains of Rhizobium leguminosarum biovar viciae (Rlv) for use of ACC as individual nitrogen source in RMM media was evaluated. Based on the results، 25 strains were found positive for ACC-deaminse، and strains according to growth in the RMM media containing ACC were categorized into three groups of strong، medium، and weak. In the next step، in 2011 a series of greenhouse experiments were conducted for investigating the effectiveness of two strains from strong group (R281Rlp and R103Sm) and one strain from weak group (R29Sm) with control treatment، for the promotion of growth parameters of canola under the salinity levels of 0، 3، 6، and 9 ds/m in factorial format experiment as randomized complete block design with three replications. The Results showed that R281Rlp inoculation، even at higher salinity (9dS/m)، significantly increased wet and dry weight of root (32 and 62. 6%، respectively)، wet and dry weight of shoot (22 and 23. 5%، respectively)، height (49%) and nitrogen uptake (50%) compared to control treatment. Furthermore، at this level of salinity، R103Sm inoculation increased the uptake of Phosphorous up to 34. 5% compared to control. A positive correlation was observed between ACC-deaminase activity of bacterial isolates and plant growth parameters; especially root biomass، (Pearson correlation coefficients > 0. 82). These results revealed that the strains containing high ACC-deaminase activity were more successful in improving the growth parameters of canola seedling، which confirms that using of these strains may be suggested as a biologic alternative to the amelioration of increasingly saline stress.

Some strains of Rhizobia known as the most useful soil bacteria are able to produce 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and reduce stress ethylene level in plants. In this research، four strong (R4-Sm، R35-Sm، R71-Sm and R122-Sm)، one mild (R94-Sm)، two weak (R11-Sm and R64-Sm) and two ACCd- (not containing ACC deaminase) strains (R138-Sm and R162-Sm) from Sinirhizobium meliloti were selected for root elongation assay in wheat plant. Experimental treatments were 9 levels of rhizobia and one level as a blank، 2 levels of L-TRP as the precursor of IAA production، 2 levels of Ag as a chemical inhibitor of ethylene action and 2 levels of IAA. The experiment was conducted in completely randomized design in a factorial arrangement with four replications in 24 days، then root length and shoot length were measured. Results showed that ACC deaminase containing rhizobial strains could significantly increase root length in comparison to the blank. Such increase was observed in shoot length as well. Strains R71-Sm and R122-Sm (strong) and R94-Sm (mild) were more effective in improving growth factors of wheat plant.