The regulatory network of cluster‐root function and development in phosphate‐deficient white lupin ( Lupinus albus ) identified by transcriptome sequencing

作者：Zhengrui Wang, Daniel Straub, Huaiyu Yang, A. Kania, Jianbo Shen, Uwe Ludewig, Günter Neumann · 发表于：Physiologia Plantarum · 年份：2014 · DOI：10.1111/ppl.12187 · 被引用次数：89 · 研究领域：Plant nutrient uptake and metabolism、Plant Molecular Biology Research、Plant Stress Responses and Tolerance

Lupinus albus serves as model plant for root-induced mobilization of sparingly soluble soil phosphates via the formation of cluster-roots (CRs) that mediate secretion of protons, citrate, phenolics and acid phosphatases (APases). This study employed next-generation sequencing to investigate the molecular mechanisms behind these complex adaptive responses at the transcriptome level. We compared different stages of CR development, including pre-emergent (PE), juvenile (JU) and the mature (MA) stages. The results confirmed that the primary metabolism underwent significant modifications during CR maturation, promoting the biosynthesis of organic acids, as had been deduced from physiological studies. Citrate catabolism was downregulated, associated with citrate accumulation in MA clusters. Upregulation of the phenylpropanoid pathway reflected the accumulation of phenolics. Specific transcript expression of ALMT and MATE transporter genes correlated with the exudation of citrate and flavonoids. The expression of transcripts related to nucleotide degradation and APases in MA clusters coincided with the re-mobilization and hydrolysis of organic phosphate resources. Most interestingly, hormone-related gene expression suggested a central role of ethylene during CR maturation. This was associated with the upregulation of the iron (Fe)-deficiency regulated network that mediates ethylene-induced expression of Fe-deficiency responses in other species. Finally, transcripts related to abscis...