Guard cell metabolic alterations induced by NtSUS2
silencing
We have carried out a metabolite profiling analysis in guard cells of
WT, L3 and L13 harvested in the dark and 120 min after the transition to
the light. Partial least square discriminant analysis (PLS-DA) and
orthogonal PLS-DA (orthoPLS-DA) were performed using the relative
metabolic changes observed in each genotype during dark-to-light
transition. Both PLS-DA and orthoPLS-DA indicate that reduced guard cellNtSUS2 expression substantially alter the relative metabolic
changes during dark-to-light transition, given that both L3 and L13 were
clearly separated from WT by the first components (Figures 6A,B; S5A,B).
Scatter plots (S-plots) from the orthoPLS-DA and variable importance in
projection (VIP) scores of the PLS-DA models demonstrate that several
metabolites pertaining to the groups of carbohydrates, amino acids and
tricarboxylic acid (TCA) cycle intermediates were responsible for the
discrimination observed among the genotypes (Figures 6C,D; S5C,D). Amino
acids such as serine and alanine and the TCA cycle intermediates
citrate, isocitrate, aconitate and fumarate have increased relative
content whilst adipic acid and trehalose have lower relative content in
WT, when compared to the transgenic lines after dark-to-light transition
(Figures 6C,D; S5C,D).