An explanatory model of temperature influence on flowering through whole-plant accumulation of FT

Temperature plays a critical role in the growth and development of plants and has a large influence on crop yield. Many models use thermal time to predict plant responses to temperature, alone and in conjunction with other environmental factors such as photoperiod, but this method remains imprecise.

In a study recently published in in silico Plants, Dr. Hannah Kinmonth-Schultz and her coauthors propose a new model to predict flowering time by incorporating the molecular and genetic underpinnings driving the response of flowering to temperature.

The Arabidopsis Framework Model was used to assess the mechanistic basis of plant temperature response through accumulation of the key flowering inducer gene FLOWERING LOCUS T (FT), which is expressed in the leaves. “In our previous work, we found higher FT levels after a drop to cool temperatures. This was contrary to previous works showing FT suppressed in constant cool temperatures and to the concept of thermal time. It got me thinking about the different ways through which temperature could influence flowering, and I began to try to reconcile the modulations of FT with the slower growth usually observed under cooler temperatures,” says Dr. Hannah Kinmonth-Schultz, Postdoctoral Researcher at the University of Kansas and former graduate student at the University of Washington.

After measuring FT production in differently aged leaves, the model was modified by adding mechanistic temperature influence on FT transcription and by causing whole-plant FT to accumulate with leaf growth.

Direct influence of temperature on FT transcription combined with indirect temperature influence on FT as accumulated with leaf growth improved the prediction of flowering time, when compared to FT as influenced solely by traditional thermal time. This work suggests that the overall amount of FT, governed by production, influences the developmental stage (leaf number) at which flowering occurs, while the rate of whole-plant FT accumulation, governed by leaf growth, influences when (in days) this transition occurs.

The model used in this research is freely available online at https://fairdomhub.org/assays/1011.