Yang Hong, Li Ping, Jin Guihua, Gui Daping, Liu Li, Zhang Chengjun
Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Plant Divers. 2020 Nov 13;44(1):116-125. doi: 10.1016/j.pld.2020.11.004. eCollection 2022 Jan.
Plant adaptation to drought stress is essential for plant survival and crop yield. Recently, harnessing drought memory, which is induced by repeated stress and recovery cycles, was suggested as a means to improve drought resistance at the transcriptional level. However, the genetic mechanism underlying drought memory is unclear. Here, we carried out a quantitative analysis of alternative splicing (AS) events in rice memory under drought stress, generating 12 transcriptome datasets. Notably, we identified exon skipping (ES) as the predominant AS type (>80%) in differential alternative splicing (DAS) in response to drought stress. Applying our analysis pipeline to investigate DAS events following drought stress in six other plant species revealed variable ES frequencies ranging from 9.94% to 60.70% depending on the species, suggesting that the relative frequency of DAS types in plants is likely to be species-specific. The dinucleotide sequence at AS splice sites in rice following drought stress was preferentially GC-AG and AT-AC. Since U12-type splicing uses the AT-AC site, this suggests that drought stress may increase U12-type splicing, and thus increase ES frequency. We hypothesize that multiple isoforms derived from exon skipping may be induced by drought stress in rice. We also identified 20 transcription factors and three highly connected hub genes with potential roles in drought memory that may be good targets for plant breeding.
植物对干旱胁迫的适应对于植物存活和作物产量至关重要。最近，利用由反复的胁迫和恢复循环诱导产生的干旱记忆，被认为是在转录水平提高抗旱性的一种手段。然而，干旱记忆背后的遗传机制尚不清楚。在此，我们对干旱胁迫下水稻记忆中的可变剪接（AS）事件进行了定量分析，生成了12个转录组数据集。值得注意的是，我们确定外显子跳跃（ES）是响应干旱胁迫的差异可变剪接（DAS）中主要的AS类型（>80%）。将我们的分析流程应用于研究其他六种植物在干旱胁迫后的DAS事件，结果显示ES频率因物种而异，范围从9.94%到60.70%，这表明植物中DAS类型的相对频率可能具有物种特异性。干旱胁迫后水稻AS剪接位点处的二核苷酸序列优先为GC-AG和AT-AC。由于U12型剪接使用AT-AC位点，这表明干旱胁迫可能会增加U12型剪接，从而提高ES频率。我们推测水稻中干旱胁迫可能会诱导产生多种源自外显子跳跃的异构体。我们还鉴定出20个转录因子和3个在干旱记忆中具有潜在作用的高度连接的枢纽基因，它们可能是植物育种的良好目标。
