Warm ambient temperature effects on flowering time in Brassica crops

Global warming is deleterious for crops and agriculture in general. However, most of our knowledge is derived from studies in the model plant Arabidopsis thaliana. In Arabidopsis a slight ambient temperature results in an acceleration of flowering time due to changes in the expression of the FT gene, the so called "florigen". To transfer this knowledge to agronomic species, scientists from Centro de Biotecnología y Genómica de Plantas UPM - INIA, are working on crops of the Brassicaceae family related to Arabidopsis such as Brassica napus (rapeseed) and Brassica rapa (turnip, Chinese cabbage).

Del Olmo et al. (2019) isolated a B. rapa FT mutant and determined that its function was essential to flower in this specie (A). They also observed that, unlike what happens in Arabidopsis, the higher ambient temperature produced a delay in B. rapa flowering time. The molecular analysis of this phenomenon determined that the delay in flowering time is associated with the regulation of the expression of the B. rapa FT gene by epigenetic mechanisms related to histone variant H2A.Z dynamics. The authors conclude that different Brassica species use similar epigenetic mechanisms but in a different way to modulate their flowering time in response to changes in ambient temperature (B).

This work contributes to better understand how flowering time is regulated in B. rapa and opens the door to the study of other related Brassica crops. In the long term, these results will aid to obtain novel Brassica crops varieties better adapted to the conditions of an increasingly changing environment.