Growth response to ionic and osmotic stress of NaCl in salt-tolerant and salt-sensitive maize.
Salt-tolerant maize (STM) and salt-sensitive maize (SSM) were treated with 100 mM NaCl for 1, 3 and 6 d and the contents of Na+ and Cl(-) (cps) of different organelles of leaf cells determined by X-ray microanalysis. The results showed that Na+ and Cl(-) entered the cytoplasm, vacuole, chloroplast and apoplast simultaneously. When STM and SSM were treated in 100 mM NaCl at atmospheric pressure (-P) and with pressure equivalent to the osmotic pressure of the NaCl (+P), the dry weights of STM (+P) and SSM (+P) plants were greater than that of STM (-P) and SSM (-P) plants, showing that the inhibitory effect of salt on plant growth was at least partially due to the osmotic effect of the NaCl. When STM and SSM were treated with NaCl and iso-osmotic polyethlene glycol, the dry weights of plants given the iso-osmotic polyethlene glycol treatment were lower for both maize lines than that of the NaCl-treated plants. Our data show that under NaCl stress, both STM and SSM seedlings simultaneously suffered from osmotic and ion stresses.
Institute of Plant Stress, Shandong Normal University, Jinan 250014, China. zhaokfkf@126.com
Ke-Fu
KF
Zhao
Jie
J
Song
Hai
H
Fan
San
S
Zhou
Meng
M
Zhao
D018533:Biomass; D002451:Cell Compartmentation / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism; D004553:Electric Conductivity; D007477:Ions / Q000378:metabolism; D009997:Osmotic Pressure / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology; D011312:Pressure; D055049:Salt Tolerance / Q000187:drug effects*; D055051:Salt-Tolerant Plants / Q000187:drug effects* / Q000254:growth & development*; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects*; D003313:Zea mays / Q000187:drug effects* / Q000254:growth & development*
D002712:Chlorides; D007477:Ions; D011092:Polyethylene Glycols; D012965:Sodium Chloride; D012964:Sodium