Genes Responsible for Inflorescence Architecture in Tomato

Difference in the branching of plant inflorescences, or shoot-bearing flowers, determines plant reproductive success and crop yield. Zachary Lippman and colleagues at the Hebrew University in Israel discovered a genetic mechanism that determines pattern of flower growth in the Solanaceae (nightshade) family of plants that includes tomato, potato, pepper, eggplant, tobacco, petunia, and deadly nightshades. Unlike other plants such as poppies and sunflowers that grow as single flower per stalk, members of the nightshade family have several branches each carrying a flower. According to the scientists, manipulation of this genetic pathway can turn a typical tomato vine into a highly branched structure with hundreds of flower-bearing shoots.

The tomato mutants compound inflorescence (S) and anantha (AN) have long been known to produce large numbers branches and hundred of flowers. The researchers identified the altered genes in the S and AN mutants. The S and AN genes are members of the well known homeobox and F-box gene families, respectively. These genes play a crucial regulatory role in patterning both animals and plants. The two genes work in sequence to regulate the timing of development of a branch and a flower – so, for example, slowing down the pathway that makes a flower allows for additional branches to grow.

The open access article published by PLoSONE is available at  http://dx.doi.org/10.1371/journal.pbio.0060288