Overlapping expression patterns and differential transcript levels of phosphate transporter genes in arbuscular mycorrhizal, Pi-fertilised and phytohormone-treated Medicago truncatula roots.
A microarray carrying 5,648 probes of Medicago truncatula root-expressed genes was screened in order to identify those that are specifically regulated by the arbuscular mycorrhizal (AM) fungus Gigaspora rosea, by P(i) fertilisation or by the phytohormones abscisic acid and jasmonic acid. Amongst the identified genes, 21% showed a common induction and 31% a common repression between roots fertilised with P(i) or inoculated with the AM fungus G. rosea, while there was no obvious overlap in the expression patterns between mycorrhizal and phytohormone-treated roots. Expression patterns were further studied by comparing the results with published data obtained from roots colonised by the AM fungi Glomus mosseae and Glomus intraradices, but only very few genes were identified as being commonly regulated by all three AM fungi. Analysis of P(i) concentrations in plants colonised by either of the three AM fungi revealed that this could be due to the higher P(i) levels in plants inoculated by G. rosea compared with the other two fungi, explaining that numerous genes are commonly regulated by the interaction with G. rosea and by phosphate. Differential gene expression in roots inoculated with the three AM fungi was further studied by expression analyses of six genes from the phosphate transporter gene family in M. truncatula. While MtPT4 was induced by all three fungi, the other five genes showed different degrees of repression mirroring the functional differences in phosphate nutrition by G. rosea, G. mosseae and G. intraradices.
Grunwald
Ulf
U
Max-Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse, 35043 Marburg, Germany.
Guo
Wenbing
W
Fischer
Kerstin
K
Isayenkov
Stanislav
S
Ludwig-Müller
Jutta
J
Hause
Bettina
B
Yan
Xiaolong
X
Küster
Helge
H
Franken
Philipp
P
D018533:Biomass; D005308:Fertilizers; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D055137:Glomeromycota / Q000187:drug effects / Q000502:physiology; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics / Q000382:microbiology*; D005810:Multigene Family; D038821:Mycorrhizae / Q000187:drug effects / Q000502:physiology*; D028061:Phosphate Transport Proteins / Q000235:genetics* / Q000378:metabolism; D010710:Phosphates / Q000494:pharmacology*; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
D005308:Fertilizers; D028061:Phosphate Transport Proteins; D010710:Phosphates; D010937:Plant Growth Regulators; D012333:RNA, Messenger; D018749:RNA, Plant