Juicy transgenics

Citrus trees have a long juvenile phase (6-20 years) that delays their reproductive development. In the March Nature Biotechnology, Pena et al. report genetic experiments that accelerated the citrus flowering time (Nature Biotechnology 2001, 19:263-267). They produced transgenic juvenile orange trees that constitutively express Arabidopsis LEAFY (LFY) or APETALA1 (AP1) genes driven by the cauliflower mosaic virus promoter. Both of these flowering genes could shorten the juvenile phase and promote early flowering in the citrus plants. The transgenic flowers were normal and fertile. Furthermore, these traits were inherited in subsequent generations of plants a dominant fashion. Such fruitful results will contribute to the genetic improvement of orange trees and provide good news for citrus lovers.