A METHOD TO ACCELERATE DORMANCY RELEASE IN ARABIDOPSIS THALIANA THAT MIMICS DRY STORAGE ON THE GENETIC LEVEL
Buijs, G.1, Kodde, J. 2, Groot, S.2 and Bentsink L.1
1Laboratory of Plant Physiology, Wageningen University, Wageningen, the Netherlands
2Plant Research International, Wageningen University and Research, Wageningen, the Netherlands
The seed life span stretches from when the seeds reach maturity on the mother plant until the seed is not viable enough anymore to germinate. At the start of the seed life span, seeds possess a genotype specific level of dormancy. A dormant seed is viable but will not germinate even though the environment is favourable. The genetic basis for seed dormancy is well defined: Quantitative Trait Loci (QTL) for seed dormancy have been identified (DELAY OF GERMINATION) but thus far only for DOG1 an underlying gene has been identified.
Arabidopsis thaliana is a wide-spread species of which accessions have been collected from very different natural habitats. The level of dormancy can vary tremendously between these different accessions. The accessions often used in research have low dormancy (Colombia-0, Landsberg erecta), but some accessions (Cape Verde Islands, Iberian Peninsula populations) can remain dormant for over a year during dry storage (after-ripening, AR). Studying these deep dormant accessions will aid in seed dormancy research, but is limited due to time constrains.
In seed dormancy and longevity research, treatments to artificially accelerate the seed life span are used. These treatments usually comprise storage at high temperatures and high relative humidity or fully imbibed (stratification). However, these artificial treatments do not always mimic dry seed storage (AR) at a genetic level. The alleviation of dormancy during dry seed storage is thought to be mainly caused by the oxidation of seed proteins and mRNAs. Based on the role of oxidation in the dormancy release and ageing process, we use the EPPO (Elevated Partial Pressure of Oxygen) system to accelerate dormancy release. In the EPPO system, seeds are stored under increased ambient air and thus increased oxygen pressure. EPPO has already shown to accelerate seed ageing. Here, we show that also dormancy release can be accelerated and mimicked in a non-invasive manner by the EPPO system. We used a genetics approach to reveal whether EPPO dormancy release occurs by the same mechanisms as seed dry AR.