Figure 1.

Suppression of the small fruit phenotype exhibited by homozygous 35S:2ox2/28 plants. A, Treatment of 28c flowers with GA₃ restores fruit size. B, Schematic representation of the construct designed to silence the 35S:2ox2/28c transgene by posttranscriptional gene silencing/RNA interference (RNAi). C, Fruit from self-pollinated WT and 28c plants and from plants homozygous for 28c and the 35S:hp2ox2 construct. The inset shows 2ox2 mRNA levels, measured by semi-quantitative reverse transcriptase-PCR with β-tubulin as a control, in rosettes of WT, 28c+35S:hp2ox2/1n, 28c+35S:hp2ox2/1v, and 28c plants. D, Schematic representation of a self-pollinated hemizygous 35S:2ox2/28c flower at anthesis, indicating the growth of haploid pollen tubes through the transmitting tract to fertilize ovules containing the female gametophyte (egg). WT pollen tubes can fertilize ovules throughout the ovary, whereas 28c pollen tubes can generally only reach ovules near the stigma. E, Suppression of the 28c fruit phenotype by gar2-1 and rga-2, alleles known to increase GA response in other organs.