Zhen A.,Northwest Agriculture and Forestry University |
Zhen A.,Key Laboratory of Protected Horticultural Engineering in Northwest |
Zhen A.,Shaanxi Province Facility Agriculture Engineering Center |
Hu X.-H.,Northwest Agriculture and Forestry University |
And 14 more authors.
Chinese Journal of Applied Ecology | Year: 2016
The effect of exogenous γ-aminobutyric acid (GABA) on NO3--N assimilation in muskmelon under Ca(NO3)2 stress was investigated in 'Yipintianxia 208', a salt-sensitive melon variety cultured under deep flow hydroponics which simulated soil salinization. The results showed that under Ca(NO3)2 stress, the activities of nitrate reductase (NR), glutamate synthetase (GS) and glutamate amino transferase (GOGAT) in muskmelon seedlings were significantly reduced, while the activities of glutamate dehydrogenase (GDH), glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate aminotransferase (GPT) were enhanced, leading to increased contents of NH4+-N and total amino acids, and decreased contents NO3--N and soluble protein in muskmelon, which further severely inhibited plant growth and photosynthesis of muskmelon seedlings. Exogenous GA- BA effectively improved the absorption of NO3--N in muskmelon roots and its transportation from root to shoot under Ca(NO3)2 stress, and improved NH4+-N assimilation by enhancing NR, GS and GOGAT activities in muskmelon seedlings. Exogenous GABA also reduced NH4+ release by limiting GDH deamination, thus further alleviated the toxication of NH4+-N induced by Ca(NO3)2 stress. In addition, foliage spraying of GABA could regulate amino acids metabolic pathways and promote pro- tein synthesis. The results suggested that exogenous GABA could improve NO3--N assimilation and regulate amino acids metabolism to alleviate Ca(NO3)2 stress damage in muskmelon seedlings. © 2016, Science Press. All right reserved.
Xiang L.-X.,Northwest Agriculture and Forestry University |
Xiang L.-X.,Key Laboratory of Protected Horticultural Engineering in Northwest |
Xiang L.-X.,Shaanxi Province Facility Agriculture Engineering Center |
Hu L.-P.,Northwest Agriculture and Forestry University |
And 11 more authors.
Chinese Journal of Applied Ecology | Year: 2015
The regulatory effect of exogenous γ-aminobutyric acid (GABA) on metabolism of reactive oxygen species (ROS) in melon chloroplasts under short-term salinity-alkalinity stress were investigated in melon variety 'Jinhui No.1', which was cultured with deep flow hydroponics. The result showed that under salinity-alkalinity stress, the photosynthetic pigment content, MDA content, superoxide anion (O2 -) production rate and hydrogen peroxide (H2O2) content in chloroplast increased significantly, the contents of antioxidants ascorbic acid (AsA) and glutathione (GSH) increased, and the activities of H+-ATPase and H+-PPiase were inhibited obviously. With exogenous GABA application, the accumulations of O2 -, MDA and H2O2 induced by salinity-alkalinity stress were inhibited. Exogenous GABA alleviated the increase of photosynthetic pigment content, improved the activity of SOD, enzymes of AsA-GSH cycle, total AsA and total GSH while decreased the AsA/DHA ratio and GSH/GSSH ratio. Foliar GABA could enhance the H+-ATPase and H+-PPiase activities. Our results suggested that the exogenous GABA could accelerate the ROS metabolism in chloroplast, promote the recycle of AsA-GSH, and maintain the permeability of cell membrane to improve the ability of melon chloroplast against salinity-alkalinity stress. © 2015, Editorial Board of Chinese Journal of Applied Ecology. All right reserved.