Zhang Y.,Northwest University, China |
Zhang Y.,Key Laboratory of Protected Horticultural Engineering in Northwest China |
Zhang Y.,State Key Laboratory of Crop Stress Biology for Arid Areas |
Shi Y.,Northwest University, China |
And 13 more authors.
Chinese Journal of Applied Ecology | Year: 2013
Taking two tomato cultivars Zhongza No. 9 and Jinpengchaoguan as test objects, a hydroponic experiment was conducted to study the effects of exogenous spermidine (Spd) on the tomato seedling nitrogen metabolism and main mineral elements contents under saline-alkali stress. Under the stress, the seedling dry biomass decreased significantly, and the plant growth was inhibited. The activities of nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) and the contents of nitrate nitrogen (NO3--N) and total N, K, Ca2+, and Mg2+ in leaves and roots decreased significantly, while the contents of ammonium nitrogen (NH4+-N), and Na+ had a significant increase. The activity of glutamate dehydrogenase (GDH) in the leaves of the two cultivars and in the roots of Zhongza No. 9 increased significantly, but that in the roots of Jinpengchaoguan had less change. The total P content in the leaves of the two cultivars decreased significantly, while that in the roots of Jinpengchaoguan and Zhongza No. 9 had a significant increase and less change, respectively. Applying exogenous Spd increased the assimilation of NH4+ by the plants through increasing the NR, GS and GOGAT activities, alleviated the nitrogen metabolic disturbance caused by the saline-alkali stress, and further, promoted the absorption, release, or transportation of P, K, Ca, Mg, and Na in different organs, maintained a proper balance among the nutrients, and improved the plant saline-alkali resistance. Zhongza No. 9 was more sensitive to the saline-alkali stress than Jinpengchaoguan, and the alleviation effect of exogenous Spd on the nitrogen metabolic disturbance and nutritional out-of-balance of Zhongza No. 9 was more obvious.
Pan X.-B.,Northwest Agriculture and Forestry University |
Pan X.-B.,Key Laboratory of Protected Horticultural Engineering in Northwest China |
Xiang L.-X.,Northwest Agriculture and Forestry University |
Xiang L.-X.,Key Laboratory of Protected Horticultural Engineering in Northwest China |
And 7 more authors.
Chinese Journal of Applied Ecology | Year: 2016
Two cultivars of tomato (Solanum lycopersicum, cvs. 'Jinpengchaoguan' and 'Zhongza No. 9', with the former being more tolerant to saline-alkaline stress) seedlings grown hydroponically were subjected to salinity-alkalinity stress condition (NaCl:Na2SO4:NaHCO3:Na2CO3=1:9:9:1) without or with foliar application of 0.25 mmol·L-1spermidine (Spd), and the root morphology and physiological characteristics of mitochondrial membrane were analyzed 8 days after treatment, to explore the protective effects of exogenous Spd on mitochondrial function in tomato roots under salinity-alkalinity stress. The results showed that the salinity-alkalinity stress increased the concentrations of both mitochondrial H2O2 and MDA as well as the mitochondrial membrane permeability in the roots of the two cultivars, while it decreased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity, which impaired the mitochondria and therefore inhibited the root growth; and these effects were more obvious in 'Zhongza No. 9' than in 'Jinpengechaoguan'. Under the salinity-alkalinity stress, foliar application Spd could effectively decrease the concentrations of mitochondrial H2O2 and MDA and mitochondrial membrane permeability, while increased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity. These results suggested that exogenous Spd could effectively mitigate the damage on mitochondria induced by salinity-alkalinity stress, and the alleviation effect was more obvious in 'Zhongza No. 9' than in 'Jinpengchaoguan'. © 2016, Science Press. All right reserved.