Xia Xinhui, Fan Minhong, Liu Yuqi, Chang Xinyue, Wang Jingting, Qian Jingjing, Yang Yuchen
State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-sen University, Shenzhen, China.
College of Agriculture, Anhui Science and Technology University, Fengyang, China.
Front Plant Sci. 2023 May 8;14:1189456. doi: 10.3389/fpls.2023.1189456. eCollection 2023.
Dwarfed stature is a desired agronomic trait for pomegranate ( L.), with its advantages such as lower cost and increased yield. A comprehensive understanding of regulatory mechanisms underlying the growth repression would provide a genetic foundation to molecular-assisted dwarfing cultivation of pomegranate. Our previous study induced dwarfed pomegranate seedlings exogenous application of plant growth retardants (PGRs) and highlighted the important roles of differential expression of plant growth-related genes in eliciting the dwarfed phenotype of pomegranate. Alternative polyadenylation (APA) is an important post-transcriptional mechanism and has been demonstrated to act as a key regulator in plant growth and development. However, no attention has been paid to the role of APA in PGR-induced dwarfing in pomegranate. In this study, we characterized and compared APA-mediated regulation events underlying PGR-induced treatments and normal growth condition. Genome-wide alterations in the usage of poly(A) sites were elicited by PGR treatments, and these changes were involved in modulating the growth and development of pomegranate seedlings. Importantly, ample specificities were observed in APA dynamics among the different PGR treatments, which mirrors their distinct nature. Despite the asynchrony between APA events and differential gene expression, APA was found to regulate transcriptome influencing microRNA (miRNA)-mediated mRNA cleavage or translation inhibition. A global preference for lengthening of 3' untranslated regions (3' UTRs) was observed under PGR treatments, which was likely to host more miRNA target sites in 3' UTRs and thus suppress the expression of the corresponding genes, especially those associated with developmental growth, lateral root branching, and maintenance of shoot apical meristem. Together, these results highlighted the key role of APA-mediated regulations in fine-tuning the PGR-induced dwarfed stature of pomegranate, which provides new insights into the genetic basis underlying the growth and development of pomegranate.
矮化树型是石榴（L.）理想的农艺性状，具有成本较低和产量增加等优点。全面了解生长抑制的调控机制将为石榴的分子辅助矮化栽培提供遗传基础。我们之前的研究通过外源施用植物生长延缓剂（PGR）诱导了矮化石榴幼苗，并强调了植物生长相关基因的差异表达在引发石榴矮化表型中的重要作用。可变聚腺苷酸化（APA）是一种重要的转录后机制，已被证明在植物生长发育中起关键调节作用。然而，尚未有人关注APA在PGR诱导的石榴矮化中的作用。在本研究中，我们对PGR诱导处理和正常生长条件下APA介导的调控事件进行了表征和比较。PGR处理引发了全基因组范围内聚（A）位点使用的变化，这些变化参与调节石榴幼苗的生长发育。重要的是，在不同PGR处理的APA动态中观察到了丰富的特异性，这反映了它们的独特性质。尽管APA事件与基因差异表达不同步，但发现APA通过影响microRNA（miRNA）介导的mRNA切割或翻译抑制来调节转录组。在PGR处理下观察到对3'非翻译区（3'UTR）延长的整体偏好，这可能在3'UTR中容纳更多miRNA靶位点，从而抑制相应基因的表达，特别是那些与发育生长、侧根分支和茎尖分生组织维持相关的基因。总之，这些结果突出了APA介导的调控在微调PGR诱导的石榴矮化树型中的关键作用，为石榴生长发育的遗传基础提供了新的见解。
