AUTHOR=Yue Zhen , Pan Xiaona , Li Jiayue , Si Fengfei , Yin Lijuan , Hou Yinjie , Chen Xiaoyao , Li Xin , Zhang Yong , Ma Jianxiang , Yang Jianqiang , Li Hao , Luan Feishi , Huang Wenfeng , Zhang Xian , Yuan Li , Zhang Ruimin , Wei Chunhua 

TITLE=Whole-transcriptome analyses identify key differentially expressed mRNAs, lncRNAs, and miRNAs associated with male sterility in watermelon

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1138415

DOI=10.3389/fpls.2023.1138415

ISSN=1664-462X

ABSTRACT=<p>Male sterility is a valuable trait for watermelon breeding, as watermelon hybrids exhibit obvious heterosis. However, the underlying regulatory mechanism is still largely unknown, especially regarding the related non-coding genes. In the present study, approximately 1035 differentially expressed genes (DEGs), as well as 80 DE-lncRNAs and 10 DE-miRNAs, were identified, with the overwhelming majority down-regulated in male-sterile floral buds. Enrichment analyses revealed that the general phenylpropanoid pathway as well as its related metabolisms was predicted to be altered in a mutant compared to its fertile progenitor. Meanwhile, the conserved genetic pathway <italic>DYT1</italic>-<italic>TDF1</italic>-<italic>AMS</italic>-<italic>MS188</italic>-<italic>MS1</italic>, as well as the causal gene <italic>ClAMT1</italic> for the male-sterile mutant Se18, was substantially disrupted during male reproductive development. In addition, some targets of the key regulators <italic>AMS</italic> and <italic>MS188</italic> in tapetum development were also down-regulated at a transcriptional level, such as <italic>ABCG26</italic> (<italic>Cla004479</italic>), <italic>ACOS5</italic> (<italic>Cla022956</italic>), <italic>CYP703A2</italic> (<italic>Cla021151</italic>), <italic>PKSA</italic> (<italic>Cla021099</italic>), and <italic>TKPR1</italic> (<italic>Cla002563</italic>). Considering lncRNAs may act as functional endogenous target mimics of miRNAs, competitive endogenous RNA networks were subsequently constructed, with the most complex one containing three DE-miRNAs, two DE-lncRNAs, and 21 DEGs. Collectively, these findings not only contribute to a better understanding of genetic regulatory networks underlying male sterility in watermelon, but also provide valuable candidates for future research.</p>