Flowering Time
Control of the Floral Transition
An important developmental response, which can have a major impact on crop yield and quality is the timing of flowering. Following germination, most plants go through a period of vegetative growth, in which they produce leaves, photosynthesize, and accumulate biomass and energy reserves before transitioning to reproductive growth in which those stored energy reserves are used for the production of flowers and seeds. The precise timing of flowering is a therefore a major determinant of reproductive success and plants have evolved complex genetic control networks which monitor the prevailing environmental conditions to ensure that flowering is triggered at the most appropriate time. Mendel has identified novel transcription factors which control these networks and has shown that they can be applied to either trigger flowering, or to delay or prevent flowering, depending upon the desired application. In many cases, domesticated plants are not grown under similar conditions to the habitats in which they evolved and their intrinsic floral control mechanisms are not well suited to the intended human use. Thus for example, some types of ornamentals have to be exposed to artificially altered day-lengths and temperatures through very costly greenhouse regimes in order to induce them to flower in time for a special date such as Christmas or Easter. Mendel has identified gene networks involved in triggering these responses and has identified candidate transcription factors than can be used to activate flowering in a similar manner to light and temperature treatments. Conversely, for many forage and biofeedstock applications, it is desirable to inhibit the floral transition and to maintain the plant in a vegetative state where it continues to assimilate carbon dioxide and accumulate biomass rather than dissipating those resources on seed production. As such, a number of Mendel technologies are being deployed in forage species such as alfalfa as well as in biofuel feedstock crops including eucalyptus and perennial grasses.
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