Arabidopsis seeds

Mother plants teach seeds about seasons and give them a thicker coat when it's cold

New research from the University of Exeter and the John Innes Centre has found that 'mother' plants remember the seasons and use this memory to teach their seeds the time of year and tell them when they should germinate. The University of Exeter's mass spectrometry and next generation DNA sequencing facilities were used in the analysis.

In the study of Arabidopsis thaliana - a common weed often used as a model for plant research - the scientists found that the mother plant plays an important role in sensing temperature and forms a long term temperature memory which she uses to control the behaviour of her progeny seeds. These temperature memories enable seeds to determine time of year and modify their germination rates to ensure that their growth and development is coordinated with the seasons.

If the mother experiences warmer temperatures, it produces more of a protein called Flowering Locus T (FT for short) which in the fruit of the plant, represses production of tannins, making seed coats thinner and more permeable, meaning they will germinate quicker.

Conversely if the mother plant experiences cooler temperatures prior to flowering it will produce less FT protein in its fruit and therefore produce more tannins. Seed coats will be thicker and less permeable and will germinate later. In this way the mother plant can manipulate seed germination to be optimal for the time of year. 

We know that if the environment during seed production is not optimal this can result in poor germination. With climate change making suboptimal conditions more frequent, having a better understanding how plants communicate with their seeds will help us optimise seed quality for crops and domestic use.

The research funded by the BBSRC and the Royal Society has implications for improving crop yields by helping us to adapt how our crops respond to changes in climate and temperature.

Dr Penfield of the John Innes Centre said: "By understanding how the mother plant uses temperature information to influence the vigour of her seeds we can begin to develop strategies for breeding seeds with more resilience to climate change."

The FT protein is known to influence when a plant flowers depending on the length of day. The research went on to show the influence of this protein on seed dormancy was entirely separate from its influence on flowering time.

The paper 'Maternal temperature history activates Flowering Locus T in fruits to control progeny dormancy according to time of year' is published in the Proceedings of the National Academy of Sciences (PNAS).

Date: 16 December 2014

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