Ölcer et al. [38] observed that the inactivation or loss of Rubisco
reduces CE, whereas the reduction in Rmax was associated with a
reduction in sedoheptulose-1,7-bisphosphatase, a key regulatory
enzyme in the Calvin cycle. LNT induced a significant decrease
in CE, Rmax, and initial and total Rubisco activities (Table 2). The
Calvin cycle regeneration phase was downregulated to correct the
decrease in CO2 assimilation. Environmental factors are known
to affect gene expression. The effect of LNT on the gene expression
of the large (rbcL) and small (rbcS) subunits of Rubisco was
determined by RT-qPCR (Table 3). LNT negatively affected the transcription
of rbcL and rbcS. The transcription in the 6 ◦C-treated plant
was more significantly inhibited. This finding is in agreement with
the results of a previous study