Plants are unique creations of nature. They are able to endure all the types of stress by staying just at one place. Scientists all over the world have been trying to understand the secret of their survival. Studies have revealed that plants use ‘priming’ or ‘acclimatization’ to build up resistance against stress of various kinds, be it biotic or abiotic. Epigenetic changes in the plant genome has been credited for this environment-induced stress memory, and it is known to be heritable. However, it is still not known how this stress memory is passed over generations, also known as ‘transgenerational stress memory’.
Wibowo et al. investigated the transgenerational stress response in Arabidopsis plants. Female plants were shown to pass the stress memory to the offspring, as male germline has widespread DNA glycosylase activity which resets the epigenetic marks and leads to loss of stress memory. In contrast to earlier studies of large scale changes in global DNA methylation due to stress, they found that discrete regions in the DNA, especially rich in transposable element-related regions, are exposed to DNA methylation changes due to salinity stress. They also found that this adaptive memory may not be just due to DNA methylation changes, and is regulated by a complex process.
The team found that a small fraction of the epigenetic change is transferred to the offspring after repeated stress exposure, but is lost in the subsequent generations if the stress is absent. However, this response may be different in perennial plants which have a much longer life span compared to the model plant Arabidopsis used in this study.
The article is based on the research paper published in eLife.