The Genetic Control of Nectary Development

The nectary gland mediates the interactions between flowering plants and their pollinators and defenders. Nectar is the main reward to pollinators for pollination services. Understanding the molecular basis of nectary development has economic and evolutionary significance. In rosids and asterids, CRABS CLAW (CRC) is a master regulator of nectary development. In addition, CRC orchestrates carpel development and floral meristem termination and is controlled by the B-, C-, and E-class genes. In basal eudicots, the STY genes play the key role in nectary formation through the auxin biosynthesis pathway. Nectar is the most important reward offered by flowering plants to pollinators for pollination services. Since pollinator decline has emerged as a major threat for agriculture, and the food demand is growing globally, studying the nectar gland is of utmost importance. Although the genetic mechanisms that control the development of angiosperm flowers have been quite well understood for many years, the development and maturation of the nectar gland and the secretion of nectar in synchrony with the maturation of the sexual organs appears to be one of the flower's best-kept secrets. Here we review key findings controlling these processes. We also raise key questions that need to be addressed to develop crop ecological functions that take into consideration pollinators' needs. Nectar is the most important reward offered by flowering plants to pollinators for pollination services. Since pollinator decline has emerged as a major threat for agriculture, and the food demand is growing globally, studying the nectar gland is of utmost importance. Although the genetic mechanisms that control the development of angiosperm flowers have been quite well understood for many years, the development and maturation of the nectar gland and the secretion of nectar in synchrony with the maturation of the sexual organs appears to be one of the flower's best-kept secrets. Here we review key findings controlling these processes. We also raise key questions that need to be addressed to develop crop ecological functions that take into consideration pollinators' needs. a putative TF that controls processes such as carpel development, floral meristem termination, and floral nectary formation. a sugar-rich, phloem-derived solution that contains products of primary and secondary metabolism. secretory nectar-producing organ formed anywhere on the plant besides the root. a molecule that binds to a DNA-regulatory sequence to modulate the rate of gene transcription. a concentric ring of floral organs. the gene family named after the CRC-like appearance of the apically unfused carpels of the crc-1 mutant.