Some studies on the effect of putrescine, ascorbic - Ozean ...

Chemical composition:
Pigments content: data in Table (3) showed that, the leaves contents of photosynthetic pigments
(chlorophyll a, b, a+b and carotenoids) increased by increasing amino acids concentration compared
with the untreated plants. In addition, data indicated that the amino acids treatments which were used
in this study had significant effect on all photosynthetic pigments. Plants treated with 100 ppm
tryptophan had the highest total chlorophyll content (1.63 mg/g FW), while untreated plants gave the
lowest value (1.27 mg/g FW). The recorded data also revealed that plants treated with tryptophan at
100 ppm had the highest carotenoids content, compared to that found in plants receiving any other
treatments. The comparison between the effect of phenylalanine and tryptophan revealed that the
influence of tryptophan on increasing the photosynthetic pigments (especially at the rate of 100 ppm,
which can be described as the most effective treatment) was superior to that of Shoola (2000) on
Lavendula multifida plant and Abou Dahab and Abd El-Aziz (2006) on Philodendron erubescens
plants.
As for the interaction between the different levels of the two amino acids (phenylalanine+ tryptophan)
application, the higher values provided when spraying 100 ppm phenylalanine and 100 ppm
tryptophan. The positive effect of foliar amino acids on enhancing all photosynthetic pigments
percentage may be due to the succnyl COA (Kerb's cycle intermediate) and the amino acid glycine,
initiate the biosysnthetic pathway leading to chlorophyll formation.
Total soluble sugars contents:
Effect of foliar application with different levels of two amino acids (phenylalanine and tryptophan)
were presented in Table (3) fig. (4) indicated that total soluble sugars contents as affected by different
levels treatments, followed the same trend obtained previously on photosynthetic pigments, were
gradually increased by increasing the level of amino acids. Comparing the effect of phenylalanine and
tryptophan , the data indicated that tryptophan was superior to phenylalanine. The percentages of
increase in the total soluble sugars content caused by treating the plants with tryptophan at 100 ppm
(compared with the control) was 52.88%. the promotive affect of the amino acids on the total soluble
sugars percentages may be due to their important role of the biosynthesis of chlorophyll molecules
which in turn affected total soluble sugars content. Similar results have been reported in other plant
species, Attoa et al.,(2002)on Iberis amara L., Iman et al.,(2005) on Catharanthus roseus L and Nahed
and Balbaa (2007) on Salvia farinacea plants. Considering the interaction, the maximum values of the
soluble sugars percentage was obtained at 100 ppm phenylalanine + 50 ppm tryptophan.
404