An Alternative Splicing Variant of PtRD26 Delays Leaf Senescence by Regulating Multiple NAC Transcription Factors in Populus

第一作者：Hou-Ling Wang

第一单位：北京林业大学

通讯作者：Zhonghai Li

 Abstract 

背景回顾：During leaf senescence, the final stage of leaf development, nutrients are recycled from leaves to other organs, and therefore proper control of senescence is thus critical for plant fitness. 

提出问题：Although substantial progress has been achieved in understanding leaf senescence in annual plants, the molecular factors that control leaf senescence in perennial woody plants are largely unknown.

主要研究：Using RNA sequencing, we obtained a high-resolution temporal profile of gene expression during autumn leaf senescence in poplar (Populus tomentosa).

结果1-基因共表达网络：Identification of hub transcription factors (TFs) by co-expression network analysis of genes revealed that senescence-associated NAC-family TFs (Sen-NAC TFs) regulate autumn leaf senescence.

结果2-PtRD26内含子滞留：Age-dependent alternative splicing (AS) caused an intron-retention (IR) event in the pre-mRNA encoding PtRD26, a NAC-TF. This produced a truncated protein PtRD26IR, which functions as a dominant-negative regulator of senescence by interacting with multiple hub Sen-NAC TFs, thereby repressing their DNA-binding activities.

结果3-剪切因子鉴定：Functional analysis of senescence-associated splicing factors identified two U2 auxiliary factors that are involved in AS of PtRD26IR.

结果4-剪切因子验证：Correspondingly, silencing of these factors decreased PtRD26IR transcript abundance and induced early senescence.

结论：We propose that an age-dependent increase of IR splice variants derived from Sen-NAC TFs is a regulatory program to fine tune the molecular mechanisms that regulate leaf senescence in trees.

 摘 要 

doi: https://doi.org/10.1093/plcell/koab046

Journal: Plant Cell

Published date: Feb 06, 2021