Submit Manuscript

Pakistan Journal of Biological Sciences

Year: 2003 | Volume: 6 | Issue: 5 | Page No.: 514-524
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail

Article Trend

Total views 570

Search

Authors

A.M. Gaber

Keywords

Research Article

Response of Water Stressed Vigna sinensis Plants to Application of IAA and/or Oxalic Acid

A.M. Gaber
The effect of water stress induced by salinity (0.25 and 0.5 % NaCl) or excessive water supply (wet and waterlogged treatments) on growth, photosynthetic activity, carbohydrates, nitrogen, mineral elements (Na, K, Ca, Mg, Mn, Fe) and some organic acids (Oxalic and citric) as well as keto acids (pyruvic and -ketoglutaric acid) were studied. A significant increase in growth criteria (shoot length , shoot fresh and dry weight, total green leaf area, specific leaf area, net assimilation rate and relative growth rate of Vigna sinensis shoot was detected in response to 0.25% NaCl and wet treatment above the respective controls, while the highest level of salinity (0.5%) and waterlogging seemed to have a decreasing effect in the previous growth parameters. Salinity stress markedly decreased the soluble sugars but greatly increased polysaccharides and total carbohydrates. On the other hand, different water treatments (wet and waterlogging) reduced significantly the carbohydrate fractions (soluble sugars, sucrose, polysaccharides and total carbohydrates). 14CO2 photoassimilation indicated that soluble, insoluble and consequently total photosynthates were reduced under the effect of water stress. A significant decrease in total-N and protein-N was observed in relation to control by higher level of salinity (0.5%) and waterlogging whereas the soluble-N was, in general, increased significantly. Meanwhile, moderate stress induced by 0.25% NaCl and wet treatment showed a non-significant responses in nitrogen fractions. Mineral contents of the tested plant (Vigna sinensis) were affected greatly by water stress. The levels of K, Ca, Mg, Mn and Fe were reduced greatly whereas Na showed a reversible situation. Waterstress induced by salinity resulted in a pronounced increase in pyruvic acid whereas the -ketoglutaric acid showed a reversible situation compared to control. Wet and waterlogging treatments decreased these two keto acids below the respective controls. Oxalic and citric acids content of Vigna sinensis shoot were decreased significantly by water stress as induced by salinity or different water treatments. Foliar application of IAA (100 ppm) to the Vigna sinensis plant at the vegetative stage or presoaking the seeds in oxalic acid (100 ppm) equilibrated, if any, the suppressive effect of water stress on growth and the metabolic activities in shoot of water stressed plant. The result revealed that IAA and/or oxalic acid alleviate the stress symptoms and regulate the changes in growth and some metabolic activities of salinity and waterlogging.
PDF Fulltext XML References Citation

Leave a Comment

Your email address will not be published. Required fields are marked *