2.6. Effects of 20% CO2
on the expression of anaerobic
respiration genes in peels and pulps of the fruits
Pyruvate decarboxylase (PDC) and alcohol dehydrogenase
(ADH) are two key genes functioning in plant anaerobic
respiration. In the peels of both fruits, the two genes were
activated after the exposure to 20% CO2
. Higher expression
levels of the genes were detected in the treated fruits than in
the control at most of the time points (Fig. 6-A). In the pulps
of both fruits, higher ADH mRNA levels were recorded in
the treated fruits (Fig. 6-B). Interestingly, strong activation
of PDC was detected in the pulps of both the control and
treated fruits on 3, 4 and 5 d, when PDC expressed similar
high levels in the control and treated fruits for two cultivars
(Fig. 6-B). The results indicate that the pulps of the both
fruits might activate anaerobic respiration even in the normal
atmosphere condition, while the peel of the fruits may undergo
the
anaerobic
respiration
only
when exposed
to
high CO2
.