A SALT TOREIANT REGULATION OF LIGHT DEACIDIFICATION IN THE LEAVES OF THE CAM PLANT KALANCHOE INTEGRIFOLIA.

A SALT TOREIANT REGULATION OF LIGHT DEACIDIFICATION IN THE
LEAVES OF THE CAM PLANT KALANCHOE INTEGRIFOLIA.
SAMIR KHALIL
Botany Department, Faculty of Science, Alexandria
University, Alexandria, EGYPT.
ABSTRACT
In the CAM plant Kalanchoe integrlfolia, effects 0)
light intensity, temperature and bicarbonate concentration
on the liyht-dependent C-transfcr from the dark synthesized
malic acid to starch In the light during phase 3 of the
diurnal CAM cycle have been studied. High light Intensity
end high teflllerature increased the rote of _lic ac:id
consumption And subsequent starch aynthesls while hiQ~er
bicarbonate -concentrations were increasingly ~nhibltory
to this C-transfer process end may ItiMUlate ttght
acidification. The concentration of bIcarbonate necessary
to I!l8ke acidification possible dudne eM. period of the
If;ht time is dependent on the Initial tissue acidity.
When acdified leev~,,·w.-re treated with DCKI. D dec I loe In
‘tarch level which amount~ -to about 23 X of’thOse of the
untreated leaves wal observed. This indic.tes that
decarboxylation of malic acid in the light II partiallY
atiftJllted by the photosynthetic CO2 fi~etion behind closed
atOlNlte.
Possible suggestions for the regulation of light
dependent C-traosfer in I. integrlfot ie leeves were
dlKusled.