RNA N6-Methyladenosine Responds to Low-Temperature Stress in Tomato Anthers

• DOI: 10.3389/fpls.2021.687826
• Publication Date: 2021-06-04T08:18:04Z
• Authors: Dandan Yang; Huachao Xu; Yue Liu; Mengzhuo Li; Muhammad Ali; Xiangyang Xu; Gang Lu
• Keywords: abscisic acid; 2. Zero hunger; 0301 basic medicine; moderate low temperature; 03 medical and health sciences; tomato anther; pollen development; Plant culture; m6A; Plant Science; 15. Life on land; SB1-1110

Cold stress is a serious threat to subtropical crop pollen development and induces yield decline. N6-methyladenosine (m6A) is the most frequent mRNA modification and plays multiple physiological functions in plant development. However, whether m6A regulates pollen development is unclear, and its putative role in cold stress response remains unknown. Here, we observed that moderate low-temperature (MLT) stress induced pollen abortion in tomato. This phenotype was caused by disruption of tapetum development and pollen exine formation, accompanied by reduced m6A levels in tomato anther. Analysis of m6A-seq data revealed 1,805 transcripts displayed reduced m6A levels and 978 transcripts showed elevated m6A levels in MLT-stressed anthers compared with those in anthers under normal temperature. These differentially m6A enriched transcripts under MLT stress were mainly related to lipid metabolism, adenosine triphosphatase (ATPase) activity, and ATP-binding pathways. An ATP-binding transcript, SlABCG31, had significantly upregulated m6A modification levels, which was inversely correlated to the dramatically downregulated expression level. These changes correlated with higher abscisic acid (ABA) levels in anthers and disrupted pollen wall formation under low-temperature stress. Our findings characterized m6A as a novel layer of complexity in gene expression regulation and established a molecular link between m6A methylation and tomato anther development under low-temperature conditions.