Fig 1.
(E)-ß-farnesene reacted with ozone to decrease ozone levels.
(A) (E)-ß-farnesene decreased ozone concentrations in empty chambers. Arrows represent 1 μL injections of either hexane (hexane injection) or (E)-ß-farnesene standard ((E)-ß-farnesene injection). (B) (E)-ß-farnesene disappeared from the chamber headspace during ozone treatment (mean+SEM). Chambers containing two (E)-ß-farnesene-perfumed plants each were fumigated with either pure air (control) or 300 ppb ozone (ozone). Air was pulled out of the chamber, through an ozone scrubber, and over Poropak Q adsorbent during the first 100 min of fumigation. (C) Supplementation of the leaf headspace with 2000 μg/plant (E)-ß-farnesene, but not with 20 μg/plant, decreased ozone-mediated leaf damage in susceptible N. tabacum cv. BelW3 plants. (D) Extractable (E)-ß-farnesene (mean+SEM) in leaves of supplemented plants after 60 min fumigation with pure air (control) or 350 ppb ozone. FM, fresh mass.
Fig 2.
Dominant sesquiterpenes in TPS10 (line 389.6), TPS10M (line 596.1), and WT (wild-type control) N. attenuata.
Retention of (A) (E)-ß-farnesene (mean+SEM) and (B) (E)-α-bergamotene emission after 3 h ozone fumigation at 300 ppb. Black bars, compressed air control; gray bars, ozone-treated. (C) Extractable sesquiterpenes (mean+SEM) from leaves of transgenic and WT plants. Black bars, (E)-ß-farnesene; gray bars, (E)-α-bergamotene. FM, fresh mass.
Fig 3.
Effects of ozone treatment (6h, 300 ppb) on TPS10 and WT N. attenuata.
Control: black bars; ozone-treated: gray bars. (A) Representative rosettes of ozone-treated and control plants. P-value of ANOVA for overall treatment effect and mean+SEM (n = 4) for (B) salicylic acid (SA) in ozone-treated and control leaves; (C) leaf moisture; (D) photosynthetic rate at 2000 μmol irradiance (E) lipid peroxidation measured in malondialdehyde (MDA) equivalents; (F) Oxidative Radical Absorbance Capacity (ORAC); and (G) rutin, a flavonoid glycoside that was the most abundant phenolic compound in leaf extracts. All measurements were made from leaf tissue harvested immediately post- fumigation except for photosynthesis, which was measured from an on-plant leaf on the following day. DM, dry mass; FM, fresh mass.
Fig 4.
Effects of UVB light treatment on physiology and fitness of TPS10M and WT Nicotiana attenuata.
Control, black bars; UVB-treated, gray bars. (A) Representative leaves from control and UV-exposed plants. P-value of ANOVA for overall treatment effect and mean+SEM for (B) Total phenolics after 8 d UV treatment, measured in gallic acid equivalents with the Folin-Ciocalteu assay (n = 6); (C) maximum quantum yield of photosystem II, Fv/Fm, after 8 d treatment (n = 6);(D) photosynthetic rate at 2000 μmol illumination after 8 d treatment (n = 6); (E) MDA equivalents after 8 d treatment (n = 3; FM, fresh mass); and (F) plant height after 8 weeks’ of treatment (n = 11); (G) total seed capsules after 8 weeks of treatment (n = 11).
Fig 5.
Effects of drought on TPS10M and WT N. attenuata.
Black bars, control; gray bars, drought treatment. P-value of ANOVA for overall treatment effect and mean+SEM (n = 6) after 6 d drought treatment for (A) shoot abscisic acid (ABA); (B) photosynthetic rate; (C) shoot and (D) root malondialdehyde (MDA) equivalents; (E) ion leakage, where leakage is expressed as conductivity of aqueous solution after 3 h room temperature incubation divided by conductivity after boiling 30 min at 95°C; (F) total fresh mass; (G) plant height after 2 weeks’ treatment; (H) total seed capsules at 74 d post-germination, 25 d after treatment began. DM, dry mass; FM, fresh mass.