Meta-analysis and candidate gene mining of low-phosphorus tolerance in maize

Plants with tolerance to low-phosphorus （P） can grow better under Iow-P conditions, and understanding of genetic mechanisms of Iow-P tolerance can not only facilitate identifying relevant genes but also help to develop Iow-P tolerant cultivars. QTL meta-analysis was conducted after a comprehensive review of the reports on O, TL mapping for Iow-P tolerance-related traits in maize. Meta-analysis pro- duced 23 consensus QTL （cQTL）, 17 of which located in similar chromosome regions to those previously reported to influence root traits. Meanwhile, candidate gene mining yielded 215 genes, 22 of which located in the cQTL regions. These 22 genes are homologous to 14 functionally characterized genes that were found to participate in plant Iow-P tolerance, including genes encoding miR399s, Pi transporters and purple acid phosphatases. Four cQTL loci （cQTL2-L cQTLS-3, cQTL6-2, and cQTL10-2） may play important roles for low-P tolerance because each contains more original QTL and has better consistency across previous reports.