Phosphorus and magnesium interactively modulate the elongation and directional growth of primary roots in Arabidopsis thaliana (L.) Heynh.
A balanced supply of essential nutrients is an important factor influencing root architecture in many plants, yet data related to the interactive effects of two nutrients on root growth are limited. Here, we investigated the interactive effect between phosphorus (P) and magnesium (Mg) on root growth of Arabidopsis grown in pH-buffered agar medium at different P and Mg levels. The results showed that elongation and deviation of primary roots were directly correlated with the amount of P added to the medium but could be modified by the Mg level, which was related to the root meristem activity and stem-cell division. High P enhanced while low P decreased the tip-focused fluorescence signal of auxin biosynthesis, transport, and redistribution during elongation of primary roots; these effects were greater under low Mg than under high Mg. The altered root growth in response to P and Mg supply was correlated with AUX1, PIN2, and PIN3 mRNA abundance and expression and the accumulation of the protein. Application of either auxin influx inhibitor or efflux inhibitor inhibited the elongation and increased the deviation angle of primary roots, and decreased auxin level in root tips. Furthermore, the auxin-transport mutants aux1-22 and eir1-1 displayed reduced root growth and increased the deviation angle. Our data suggest a profound effect of the combined supply of P and Mg on the development of root morphology in Arabidopsis through auxin signals that modulate the elongation and directional growth of primary root and the expression of root differentiation and development genes.
Department of Horticulture, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou 310058, PR China College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China.
Yaofang
Y
Niu
College of Agricultural and Biotechnology, Zhejiang University, Hangzhou 310058, PR China.
Gulei
G
Jin
Tea Research Institute, Chinese Academy of Agricultural Science, Hangzhou, 310008, PR China.
Xin
X
Li
Centre for AgriBioscience, La Trobe University, Melbourne Campus, Victoria 3086, Australia.
Caixian
C
Tang
College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China.
Yongsong
Y
Zhang
College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China.
Yongchao
Y
Liang
Department of Horticulture, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou 310058, PR China jqyu@zju.edu.cn.
Jingquan
J
Yu
D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development*; D001692:Biological Transport / Q000187:drug effects; D002452:Cell Count; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology*; D018519:Meristem / Q000187:drug effects / Q000254:growth & development; D010758:Phosphorus / Q000494:pharmacology*; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D030821:Plants, Genetically Modified; D055153:Stem Cell Niche / Q000187:drug effects
D007210:Indoleacetic Acids; D049452:Green Fluorescent Proteins; D010758:Phosphorus; D008274:Magnesium
Auxin transport; interaction; magnesium; nutrient balance; phosphorus; root growth.