Gossypium Barbadense

Based on transgenic cotton lines carrying the bacterial mtlD gene and non-transgenic, conventional
cotton variety, a greenhouse experiment was conducted to assess the effect of different levels of salt stress on
the amino acid content of both transgenic and non transgenic seeds. The amino acid profile was determined
by GC mass-spectrum. Transgenic and non-transgenic cotton seeds were grown to maturity under different
concentrations of salt stress after determining the field capacity. Seeds obtained from transgenic and non
transgenic plants showed increasing concentration of amino acids with increasing the level of salt stress.
However, the transgenic cotton seeds accumulated significant amounts of amino acids compared with nontransgenic
seeds. There were some differences in mean content of some individual amino acids between
transgenic and non transgenic seeds, with some significant differences at higher level of salt stress. Amongst
the amino acids that showed significant differences at high level of salt stress were Alanine, Proline, Glutamine,
Asparagine and histedine. The difference in amino acid content between transgenic and non transgenic plants
was also high for tryptophane, lucine and tyrocine under low level of salt stress. Accumulation of amino acids
in seeds from both transgenic and non transgenic plants as a result of salt stress appeared to play an important
role in the acclimation to salt stress of cotton plants. However, the higher accumulation of total and individual
amino acid in the seeds obtained form transgenic lines under salt stress compared with non transgenic seeds
may be a result of the expression of the mtlD gene into the genome, which might prove that transferring the
mtlD gene could be considered one of the effective strategies to produce salt tolerance cotton variety. The,
results indicated that the insertion of mtlD gene in the transgenic cottons had some influence on the synthesis
and accumulation of amino acids in transgenic seeds under salt stress.

Based on transgenic cotton lines carrying the bacterial mtlD gene and non-transgenic, conventional cotton variety, a greenhouse experiment was conducted to assess the effect of different levels of salt stress on the amino acid content of both transgenic and non transgenic seeds. The amino acid profile was determined by GC mass-spectrum. Transgenic and non-transgenic cotton seeds were grown to maturity under different concentrations of salt stress after determining the field capacity. Seeds obtained from transgenic and non transgenic plants showed increasing concentration of amino acids with increasing the level of salt stress. However, the transgenic cotton seeds accumulated significant amounts of amino acids compared with non- transgenic seeds. There were some differences in mean content of some individual amino acids between transgenic and non transgenic seeds, with some significant differences at higher level of salt stress. Amongst the amino acids that showed significant differe...

Soil salinity causes an annual deep negative impact to the global agricultural economy. In this study, the effects of salinity on early seedling physiology of two Egyptian cotton (Gossypium barbadense L.) cultivars differing in their salinity tolerance were examined. Also the potential use of a low cost mini-rhizotron system to measure variation in root system architecture (RSA) traits existing in both cultivars was assessed. Salt tolerant cotton cultivar 'Giza 90' produced significantly higher root and shoot biomass, accumulated lower Na + /K + ratio through a higher Na + exclusion from both roots and leaves as well as synthesized higher proline contents compared to salt sensitive 'Giza 45' cultivar. Measuring RSA in mini-rhizotrons containing solid MS nutrient medium as substrate proved to be more precise and efficient than peat moss/sand mixture. We report superior values of main root growth rate, total root system size, main root length, higher number of lateral roots and average lateral root length in 'Giza 90' under salinity. Higher lateral root density and length together with higher root tissue tolerance of Na + ions in 'Giza 90' give it an advantage to be used as donor genotype for desirable root traits to other elite cultivars.