Thermal stress accelerates Arabidopsis thaliana mutation rate

第一作者：Eric J. Belfield

第一单位：牛津大学

通讯作者：Nicholas P. Harberd

 Abstract 

背景回顾：Mutations are the source of both genetic diversity and mutational load.

提出问题：However, the effects of increasing environmental temperature on plant mutation rates and relative impact on specific mutational classes (e.g., insertion/deletion [indel] vs. single nucleotide variant [SNV]) are unknown.

课题重要性：This topic is important because of the poorly defined effects of anthropogenic global temperature rise on biological systems.

主要研究：Here, we show the impact of temperature increase on Arabidopsis thaliana mutation, studying whole genome profiles of mutation accumulation (MA) lineages grown for 11 successive generations at 29°C.

结果1-高温与常温下的突变率：Whereas growth of A. thaliana at standard temperature (ST; 23°C) is associated with a mutation rate of 7 × 10−9 base substitutions per site per generation, growth at stressful high temperature (HT; 29°C) is highly mutagenic, increasing the mutation rate to 12 × 10−9.

结果2-突变类型：SNV frequency is approximately two- to threefold higher at HT than at ST, and HT-growth causes an ～19- to 23-fold increase in indel frequency, resulting in a disproportionate increase in indels (vs. SNVs).

结果3-indel类型与分布：Most HT-induced indels are 1–2 bp in size and particularly affect homopolymeric or dinucleotide A or T stretch regions of the genome. HT-induced indels occur disproportionately in nucleosome-free regions, suggesting that much HT-induced mutational damage occurs during cell-cycle phases when genomic DNA is packaged into nucleosomes.

结论：We conclude that stressful experimental temperature increases accelerate plant mutation rates and particularly accelerate the rate of indel mutation.

意义：Increasing environmental temperatures are thus likely to have significant mutagenic consequences for plants growing in the wild and may, in particular, add detrimentally to mutational load.

 通讯作者 

doi: http://www.genome.org/cgi/doi/10.1101/gr.259853.119

Journal: Genome Research

Published date: Dec 17, 2020