## 2 Results
### Expression Profile of Genes of Ascorbate Biosynthesis Enzymes under Phtytohormones Treatments  
The gene expression related to Asc biosynthesis pathways in pepper was analyzed through leaf application of sodium salicylate (SA), methyl jasmonate (MeJa), ethephene (ET), and abscisic acid (ABA) phytohormones at 1, 3, 6, 12, and 24 h (PRJNA634831) [43]. Generally, phytohormones promoted different expression patterns, while MeJa and ABA down-regulated the expression of the large majority of genes involved in Asc biosynthesis pathway, and salicate and mainly ethylene seemed to increase activity of principal and alternative pathways at all points studied (Figure 11 and Table S11).  
Figure 11: Heatmap representation of genes encoding ascorbate biosynthesis pathways in pepper leaves under treatment with exogenous sodium salicate 5 mM (SA), methyl jasmonate 100 \(\upmu\)M (MeJa), ethephene 5 mM (ET), and abscisic acid 100 \(\upmu\)M (ABA) phytohormones at 1, 3, 6, 12, and 24 h (PRJNA634831). Up\(-\) and down\(-\)regulated genes are indicated in red and green colors, respectively, according to \(Z-\)score values obtained from three biological replicates. Statistical significance is shown in Table S11.  
Regarding salicate (SA), _GGP2_, the gene encoding the rate limiting step of D-mannose/L-galactose pathway was substantially up-regulated at all treatments, except at 12 h. In addition, transcript amounts of _PMM_, _GGP1_, and _GalLDH_, followed by _MIOX1_ and 3 (myo-inositol pathway) were augmented at the last two exposure times. However, the mRNA levels of _GPP_ and _GalLDH_ (at 1, 3, and 12 h), _PMI_ and _GMP1_ (at 1 or 6 h), and _GalLDH_ (at 3 h) slightly decreased in relation to controls. Ethephone (ET), a chemical precursor of ethylene, seems to activate Asc biosynthesis in leaves at all times of studied exposure, except at 1 h, when _GME1_, _GGP2_, and _GalLDH_ transcripts levels reduced (Figure 11 and Table S11). Noticeably, from 6 h onward, the large majority of genes from L-galactose pathway (_PMI2_, _PMM_, _GMP_, _GME_, _GGP_, and _GPP_) in almost all exposure times, as well as _GalDH_ and _GalLDH_, both at 24 h, increased their expression (Figure 11 and Table S11). _GME2_ member was particularly up-regulated, evidencing its responsiveness to ET. In agreement with this, specific members from alternative pathways (_GuILO2_ and _MIOX1_ and _3_) were sharply stimulated at 1 until 12 h, evidencing some contribution.  
In the case of methyl jasmonate (MeJa), several genes from L-galactose pathway, including _PMI_, _GME1_, _GGP1_, _GPP2_, _GalDH_, and _GalLDH_, were down-regulated after 1 and 3 h of treatment. Interestingly, _MIOX3_ (myo-inositol pathway) was strongly augmented at the same time, while _GuILO1_ exhibited an irregular pattern (down- and up-regulation, respectively) (Figure 11 and Table S11). Subsequently, MeJa appears to increase mRNA amounts of _GalLDH_ (6 h), and mainly of _GMP_ and _GGP_ family in the two later treatments. In leaves, abscisic acid (ABA) provoked the decrease in expression of several genes from L-galactose pathway at 1, 3, and 12 h including, _GME_, _GGP_, _GPP_, _GalDH_, and _GalLDH_ genes. Nevertheless, it appears that Asc biosynthesis was stimulated at 6 and 24 h by the up-regulation of _PMI_, _PMM_, and mostly _GME2_ and _GGP2_ members, despite some down-regulated genes in these exposure times.