Averages ± standard deviation of: phosphorus (P) concentration in irrigation solution, and corresponding P leaf concentration measured during the flowering periods, percentage of buds evolved into inflorescences, flowers to fruits, and total number of fruit per tree, all for each of the two years of study.

<p>Different letters indicate values with significant differences at <i>p</i><0.05 (6 repetition).</p

Pollen viability as affected by phosphorus levels (0.1, 1, 10 and 26 mg l^-1 P in irrigation for P1–P4 respectively).

<p>In 2012 (a) measured by Alexander reagent and in 2013 (b) by both Alexander reagent and fluorescein di-acetate (FDA) method (200–300 flowers per treatment). Different letters indicate significantly differences at p<0.05.</p

Average concentrations of total soluble carbohydrates (SCH) and glucose (a) and mannitol, sucrose and fructose (b) in the developing inflorescences from emergence to full bloom (March-April 2012).

<p>Since phosphorus level had no effect on SCH all measurements were evaluated together (n = 16). Error bars indicate standard deviation.</p

Average inflorescence fresh weight during flower development for olive trees receiving P treatments (0.1, 1, 10 and 26 mg l^-1 P in irrigation for P1–P4 respectively, n = 4).

<p>2012 (a) and 2013 (b). Error bars are standard deviation. Vertical lines denote the date of full bloom (FB) by visual evaluation.</p

Assimilation rate (a, <i>A</i>_<i>n</i>) and stomatal conductance (b, <i>g</i>_<i>s</i>) of olive trees in response to four phosphorus (P) levels (0.1, 1, 10 and 26 mg l^-1 P in irrigation for P1–P4 respectively).

<p>Measurements were taken between 10:00–12:00 over three days in early May 2012. On each day, four trees per treatment were measured (n = 16). Different letters indicate significant differences at <i>p</i><0.05.</p

Pistil fresh weight as affected by P level.

<p>Measurements were taken proximate to full bloom, 30^th April 2012 (a) and 7^th May 2013 (b) as function of P level (0.1, 1, 10 and 26 mg l^-1 P in irrigation for P1–P4 respectively). Different letters indicate significant differences between treatments at <i>p</i><0.05.</p

Altering ethylene signaling in <i>ARF2-OX</i> transgenic fruit.

<p><i>ARF2-OX</i> fruit at the mature green (MG) stage, before the visual appearance of patches, were treated with either (A) ethrel, or (B) 1-MCP, and phenotypes were observed at (A) 10 and 16, or (B) 7 and 10 DPT. (C) Ethylene emission was measured from WT and <i>ARF2-OX</i> fruit harvested at the MG stage, every 1–3 days for 16 days, the red bars and arrows indicate the breaker stage. Error bars represent SE. DPT: days post treatment.</p

Metabolic analysis of <i>ARF2-OX</i> fruit.

<p>WT and <i>ARF2-OX</i> fruit were analyzed at 42 and 53 dpa by UPLC-qTOF-MS in positive mode, (A) results are visualized by a principle component analysis (PCA) plot; and displayed as histograms for (B) targeted flavonoids (upper row), and targeted glycoalkaloids (lower row). (C) Isoprenoids were analyzed in WT and <i>ARF2-OX</i> fruit at 42 and 53 dpa by HPLC. Grey bars represent WT, black bars <i>ARF2-OX</i> green/yellow patches and white bars <i>ARF2-OX</i> red patches. Error bars represent SE. Statistical significance was evaluated using a student’s t-test, *p-value<0.05; dpa: days post anthesis.</p

Microarray analysis of <i>ARF2-OX</i> fruit.

<p>Gene expression was analyzed in WT at 42 dpa (mature green stage; WT-42G) and 53 dpa (red stage; WT-53R) and green (<i>ARF2-OX</i>-42G) and red (<i>ARF2-OX</i>-42R) patches from <i>ARF2-OX</i> fruit at 42 dpa by microarray analysis. Results are displayed as (A) a principal component analysis (PCA) and (B) a Venn diagram of the differentially expressed genes in the comparisons: <i>ARF2-OX</i>-42G to WT-42G; <i>ARF2-OX</i>-42R to WT-42G; and WT-53R to WT-42G. P-value<0.01 and FDR<0.05; dpa: days post anthesis.</p

Phenotype and expression levels of <i>ARF2</i> genes in <i>ARF2as</i> transgenic lines.

<p>Fruit of <i>ARF2as</i> lines were analysed for relative expression levels by qRT-PCR of (A) <i>ARF2A;</i> and (B) <i>ARF2B</i>. (C-D) The ripening of <i>ARF2as</i> fruit is delayed as compared to WT. (D-E) <i>ARF2as</i> fruit were parthenocarpic or nearly parthenocarpic with reduced number of seeds. (F) Principle component analysis (PCA) plot from untargeted analysis of metabolites. DPA: days post anthesis; error bars represent SE; Statistical significance was evaluated using a student’s t-test, **p-value<0.01.</p