{"title":"Functional analysis of <i>ZmPHR1</i> and <i>ZmPHR2</i> under low-phosphate stress in maize.","authors":"Hongmei Hu, Yikai Wang, Haixu Zhong, Binyang Li, Jingxiao Qi, Yarong Wang, Jin Liu, Shuhao Zhang, Haiying Zhang, Bowen Luo, Xiao Zhang, Zhi Nie, Hongkai Zhang, Duojiang Gao, Shiqiang Gao, Dan Liu, Ling Wu, Shibin Gao","doi":"10.1007/s11032-024-01508-2","DOIUrl":null,"url":null,"abstract":"<p><p>The PHOSPHATE STARVATION RESPONSE REGULATOR (PHR) plays a crucial regulatory role in plants during the process of responding to phosphate starvation. In this study, we combined reverse genetics and biotechnology to investigate the function of <i>ZmPHR1</i> and <i>ZmPHR2</i>, including proteins containing the Myb_DNA_banding and Myb_CC-LHEQLE structural domains, in maize seedlings. Phylogenetic analysis revealed that <i>ZmPHR1</i> and <i>ZmPHR2</i> have high homology with <i>AtPHR1</i> and <i>OsPHR2</i>, and share the characteristic features of nuclear localisation and transcriptional self-activation. Real-time quantitative PCR analysis showed that low phosphate (Pi) stress significantly induced the expression of <i>ZmPHR1</i> and <i>ZmPHR2</i> in maize seedling stage, and candidate gene association analysis further revealed the close association of these two genes with root traits under Pi stress conditions. Transgenic plants overexpressing <i>ZmPHR1</i> and <i>ZmPHR2</i> in <i>Arabidopsis</i> show a significant increase in lateral root number, fresh weight and total phosphorus accumulation under low-Pi stress. Besides, CHIP-PCR experiments identified target genes involved in hormone regulation, metal ion transport and homeostasis, phosphatase encoding, and photosynthesis, providing new insights into the biological functions of <i>ZmPHR1</i> and <i>ZmPHR2</i>. Furthermore, our study showed that ZmPHR1 interacts with six SPX domain-only proteins (ZmSPXs) in maize, while ZmPHR2 interacts with five of these proteins. <i>ZmPHR1</i> and <i>ZmPHR2</i> expression was repressed in low Pi conditions, but was up-regulated in <i>ZmSPX1</i> knockout material, according to our study of transgenic seedlings overexpressing <i>ZmSPX1</i> in maize. We identified downstream target genes involved in the phosphorus signaling pathway, which are mainly involved in plant-pathogen interactions, ascorbic acid and arabinose metabolism, and ABC transporter proteins, by RNA-seq analysis of transgenic seedlings grown under low Pi stress for 7 days. Collectively, these results provide important clues to elucidate the role and functional significance of <i>ZmPHR1</i> and <i>ZmPHR2</i> under low Pi stress and also provide insights into understand the molecular mechanism of phosphorus homeostasis in maize.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s11032-024-01508-2.</p>","PeriodicalId":18769,"journal":{"name":"Molecular Breeding","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11442720/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Breeding","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1007/s11032-024-01508-2","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRONOMY","Score":null,"Total":0}
引用次数: 0
Abstract
The PHOSPHATE STARVATION RESPONSE REGULATOR (PHR) plays a crucial regulatory role in plants during the process of responding to phosphate starvation. In this study, we combined reverse genetics and biotechnology to investigate the function of ZmPHR1 and ZmPHR2, including proteins containing the Myb_DNA_banding and Myb_CC-LHEQLE structural domains, in maize seedlings. Phylogenetic analysis revealed that ZmPHR1 and ZmPHR2 have high homology with AtPHR1 and OsPHR2, and share the characteristic features of nuclear localisation and transcriptional self-activation. Real-time quantitative PCR analysis showed that low phosphate (Pi) stress significantly induced the expression of ZmPHR1 and ZmPHR2 in maize seedling stage, and candidate gene association analysis further revealed the close association of these two genes with root traits under Pi stress conditions. Transgenic plants overexpressing ZmPHR1 and ZmPHR2 in Arabidopsis show a significant increase in lateral root number, fresh weight and total phosphorus accumulation under low-Pi stress. Besides, CHIP-PCR experiments identified target genes involved in hormone regulation, metal ion transport and homeostasis, phosphatase encoding, and photosynthesis, providing new insights into the biological functions of ZmPHR1 and ZmPHR2. Furthermore, our study showed that ZmPHR1 interacts with six SPX domain-only proteins (ZmSPXs) in maize, while ZmPHR2 interacts with five of these proteins. ZmPHR1 and ZmPHR2 expression was repressed in low Pi conditions, but was up-regulated in ZmSPX1 knockout material, according to our study of transgenic seedlings overexpressing ZmSPX1 in maize. We identified downstream target genes involved in the phosphorus signaling pathway, which are mainly involved in plant-pathogen interactions, ascorbic acid and arabinose metabolism, and ABC transporter proteins, by RNA-seq analysis of transgenic seedlings grown under low Pi stress for 7 days. Collectively, these results provide important clues to elucidate the role and functional significance of ZmPHR1 and ZmPHR2 under low Pi stress and also provide insights into understand the molecular mechanism of phosphorus homeostasis in maize.
Supplementary information: The online version contains supplementary material available at 10.1007/s11032-024-01508-2.
期刊介绍:
Molecular Breeding is an international journal publishing papers on applications of plant molecular biology, i.e., research most likely leading to practical applications. The practical applications might relate to the Developing as well as the industrialised World and have demonstrable benefits for the seed industry, farmers, processing industry, the environment and the consumer.
All papers published should contribute to the understanding and progress of modern plant breeding, encompassing the scientific disciplines of molecular biology, biochemistry, genetics, physiology, pathology, plant breeding, and ecology among others.
Molecular Breeding welcomes the following categories of papers: full papers, short communications, papers describing novel methods and review papers. All submission will be subject to peer review ensuring the highest possible scientific quality standards.
Molecular Breeding core areas:
Molecular Breeding will consider manuscripts describing contemporary methods of molecular genetics and genomic analysis, structural and functional genomics in crops, proteomics and metabolic profiling, abiotic stress and field evaluation of transgenic crops containing particular traits. Manuscripts on marker assisted breeding are also of major interest, in particular novel approaches and new results of marker assisted breeding, QTL cloning, integration of conventional and marker assisted breeding, and QTL studies in crop plants.