Abstract:
Leaves of mechanically inoculated Carica papaya L. plants
with papaya ringspot virus (PRSV) were examined for free amino
acids by using paper, thin layer and high pressure liquid chromatography
(HPLC) techniques. Seven amino acids: aspartic acid, glutamic
acid, serine, arginine, threonine, alanine and glycine were detected
by paper and thin layer chromatography and another eight amino
acids: histidine, methionine, isoleucine, leucine, lysine, tyrosine,
valine and penylalanine were detected by HPLC. A two fold
increase in the concentration of serine, alanine, arginine, threonine
and aspartic acid was observed in the leaves infected with PRSV.
Methionine, valine histidine and tyrosine contents in the infected
leaves were decreased but no significant differences were found in
the contents of glutamic acid, isoleucine and leucine, These changes
were detected in the inoculated leaves as early as three hours of
inoculation and same tendency was observed at the later stages of
disease development.
Similar changes in free amino acids were observed in the field plants
naturally infected with PRSV, despite their age and different climatic
conditions of growth.
