Fig. 4

The impact of the overexpression of PttVAP27-17 on the enzymatic saccharification of greenhouse-grown trees. a, b Glucose production rate (GPR) after 2 h of enzymatic saccharification (gL⁻¹ h⁻¹) for samples without (untreated) and with acid pretreatment (pretreated) in wild type (WT) and three transgenic lines (1–3). c, d Glucose yields after 72 h of enzymatic saccharification [g glucose per g of wood (dry weight) in samples without (untreated) and after acid pretreatment (pretreated)]. e Total wood glucose yield (TWG) after pretreatment and 72 h of enzymatic saccharification per whole tree biomass. TWG was calculated by using the formula 1/3 × π × stem radius² × stem height × wood density × glucose yield after pretreatment and 72 h of enzymatic saccharification. n = 5 for transgenic line 1 and 2, n = 3 for transgenic line 3 and n = 33 for the WT where “n” indicates number of biological replicates. Samples from the 33 WT trees were pooled to five replicate samples in all these experiments. The box plots show the median (horizontal line) with the outer limits at the 25th and 75th percentiles, the 1.5 inter-quartile ranges (whiskers) and the outliers (gray spots). Asterisks indicate significant differences from the WT at p ≤ 5% (*) according to Student’s t-test. Percentages indicate increase (+) or decrease (−) of values for lines overexpressing PttVAP27-17 compared to the WT