Abscisic acid level is not important for elevated CO2-induced
heat stress alleviation
In spite of the basal difference in ABA levels between the two
genotypes, heat stress slightly induced ABA content in both
genotypes. Under ambient CO2 and elevated CO2 treatments,
the ABA level further increased (33.5% and 48.0%, respectively)
after the recovery period only in the heat-stressed not
seedlings compared with its control (Fig. 2A). However, compared
with heat stress under the ambient CO2 treatment, the
elevated CO2 treatment did not significantly alter the ABA content
of heat-stressed seedlings of either genotype at the studied time points. Expression of the NCED2 gene remained stable
either through the heat stress and/or the elevated CO2 treatment
in leaves of the not seedlings (Fig. 2B). However, a signifi-
cant up-regulation of the NCED2 gene has been observed after
heat stress in the Ailsa seedlings with or without CO2 enrichment.
A significant increase in transcript level of AIM1 was
noticed after heat stress and recovery time points in both genotypes
compared with their respective controls (Fig. 2C). However,
transcripts of NCED2 and AIM1 were not noticeably
induced by CO2 enrichment in heat-stressed tomato seedlings
of either genotype