Warm temperatures induce transgenerational epigenetic release of RNA silencing by inhibiting siRNA biogenesis in [i]Arabidopsis[/i]

Si-Hui Zhong (1) , Jun-Zhong Liu (1) , Hua Jin (2) , Lin Lin (1) , Qun Li (1) , Ying Chen (1) , Yue-Xing Yuan (1) , Zhi-Yong Wang (3, 4) , Hai Huang (1) , Yi-Jun Qi (5) , Xiao-Ya Chen (1) , Hervé Vaucheret (6) , Joanne Chory (3, 4) , Jianming Li (2) , Zu-Hua He (1)

1 Shanghai Inst Biol Sci, Inst Plant Physiol & Ecol, Natl Key Lab Plant Mol Genet
2 Dept Mol Cellular & Dev Biol
3 Howard Hughes Med Inst
4 The Salk Institute for Biological Studies
5 Natl Inst Biol Sci
6 IJPB - Institut Jean-Pierre Bourgin

Owing to their sessile nature, plants have evolved sophisticated genetic and epigenetic regulatory systems to respond quickly and reversibly to daily and seasonal temperature changes. However, our knowledge of how plants sense and respond to warming ambient temperatures is rather limited. Here we show that an increase in growth temperature from 22 degrees C to 30 degrees C effectively inhibited transgene-induced posttranscriptional gene silencing (PTGS) in Arabidopsis. Interestingly, warmth-induced PTGS release exhibited transgenerational epigenetic inheritance. We discovered that the warmth-induced PTGS release occurred during a critical step that leads to the formation of double-stranded RNA (dsRNA) for producing small interfering RNAs (siRNAs). Deep sequencing of small RNAs and RNA blot analysis indicated that the 22-30 degrees C increase resulted in a significant reduction in the abundance of many trans-acting siRNAs that require dsRNA for biogenesis. We discovered that the temperature increase reduced the protein abundance of SUPPRESSOR OF GENE SILENCING 3, as a consequence, attenuating the formation of stable dsRNAs required for siRNA biogenesis. Importantly, SUPPRESSOR OF GENE SILENCING 3 overexpression released the warmth-triggered inhibition of siRNA biogenesis and reduced the transgenerational epigenetic memory. Thus, our study reveals a previously undescribed association between warming temperatures, an epigenetic system, and siRNA biogenesis.

Mots clés: TRANSCRIPTION FACTOR PIF4; VIRUS-RESISTANCE; FLOWERING TIME; PLANTS; GENE; INHERITANCE; PATHWAYS; RECEPTOR; STRESS; SUPPRESSION

Domaines: Sciences du Vivant [q-bio]

Si-Hui Zhong, Jun-Zhong Liu, Hua Jin, Lin Lin, Qun Li, et al.. Warm temperatures induce transgenerational epigenetic release of RNA silencing by inhibiting siRNA biogenesis in [i]Arabidopsis[/i]. Proceedings of the National Academy of Sciences of the United States of America, 2013, 110 (22), pp.9171-9176. ⟨10.1073/pnas.1219655110⟩. ⟨hal-01203983⟩