面临困难：Although natural parthenocarpic varieties are useful for breeding Solanaceae plants, their use has been limited, and little is known about their molecular and biochemical mechanisms.

发现基因：Here, we report a parthenocarpic eggplant mutant, pad-1, which accumulates high levels of auxin in the ovaries.

克隆基因：Map-based cloning showed that the wild-type (WT) Pad-1 gene encoded an aminotransferase with similarity to Arabidopsis VAS1 gene, which is involved in auxin homeostasis.

功能鉴定：Recombinant Pad-1 protein catalyzed the conversion of indole-3-pyruvic acid (IPyA) to tryptophan (Trp), which is a reverse reaction of auxin biosynthetic enzymes, tryptophan aminotransferases (TAA1/TARs).

表达模式：The RNA level of Pad-1 gene increased during ovary development and reached its highest level at anthesis stage in WT.

生物学功能：This suggests that the role of Pad-1 in WT unpollinated ovary is to prevent overaccumulation of IAA resulting in precocious fruit-set.

近缘物种：Furthermore, suppression of the orthologous genes of Pad-1 induced parthenocarpic fruit development in tomato and pepper plants.

结论：Our results demonstrated that the use of pad-1 genes would be powerful tools to improve fruit production of Solanaceae plants.