Researchers have identified some of the gene networks that determine how many flowers a plant will produce. The team focused on nightshade plants but the findings may help explain diversity in other plant families. Pinpointing the exact genes involved may allow scientists to develop more efficient crops. The details were just published in the journal Genome Research.
The nightshade family (Solanaceae) consists of about 2,700 different species of flowering plants. Solanaceae contains important food species, including tomatoes, eggplants, potatoes, and peppers. The family also includes tobacco plants and many popular ornamental flowers, such as the petunia. Solanaceae plants show a lot of variation in the number of flowers and branches produced. Tomatoes grow tons of branches containing multiple flowers while chili pepper plants tend to produce a single flower at a time. Flower-producing structures on branches or stems are called inflorescences and these determine how many flowers will develop. Researchers have recently begun studying the mechanisms behind the variation of inflorescences in the Solanaceae family.
A research team from the Cold Spring Harbor Laboratory used RNA sequencing techniques to study gene expression during the flowering periods of nightshade plants. They found that the activity of about 300 genes changed during meristem maturation. These genes were turned on later in the process in plants that produce many flowers, such as tomato plants. The genes switched on early in pepper plants. The team couldn’t easily identify specific genes but did find a gene network called BLADE-ON-PETIOLE (BOP) that encourages tomato plants to grow many flowers. If the BOP network is inactivated, the modified tomato plants produce only a few flowers at a time.
The findings provide an explanation for the diversity found in nightshade plants. If researchers continue to identify critical genes and gene networks, it could lead to the development of better crops. Though this study was centered on nightshade plants, the authors believe that their techniques could be used to study corn, wheat, and other important food crops.
Lemmon et al. The evolution of inflorescence diversity in the nightshades and heterochrony during meristem maturation. Genome Research (2016).