Transcriptome analysis of root transporters reveals participation of multiple gene families in the response to cation stress.
Plant nutrition critically depends on the activity of membrane transporters that translocate minerals from the soil into the plant and are responsible for their intra- and intercellular distribution. Most plant membrane transporters are encoded by multigene families whose members often exhibit overlapping expression patterns and a high degree of sequence homology. Furthermore, many inorganic nutrients are transported by more than one transporter family. These considerations, coupled with a large number of so-far non-annotated putative transporter genes, hamper our progress in understanding how the activity of specific transporters is integrated into a response to fluctuating conditions. We designed an oligonucleotide microarray representing 1096 Arabidopsis transporter genes and analysed the root transporter transcriptome over a 96-h period with respect to 80 mM NaCl, K+ starvation and Ca2+ starvation. Our data show that cation stress led to changes in transcript level of many genes across most transporter gene families. Analysis of transcriptionally modulated genes across all functional groups of transporters revealed families such as V-type ATPases and aquaporins that responded to all treatments, and families - which included putative non-selective cation channels for the NaCl treatment and metal transporters for Ca2+ starvation conditions - that responded to specific ionic environments. Several gene families including primary pumps, antiporters and aquaporins were analysed in detail with respect to the mRNA levels of different isoforms during ion stress. Cluster analysis allowed identification of distinct expression profiles, and several novel putative regulatory motifs were discovered within sets of co-expressed genes.
Maathuis
Frans J M
FJ
Department of Biology, University of York, PO Box 373, York YO10 5YW, UK.
Filatov
Victor
V
Herzyk
Pawel
P
Krijger
Gerard C
GC
Axelsen
Kristian B
KB
Chen
Sixue
S
Green
Brian J
BJ
Li
Yi
Y
Madagan
Kathryn L
KL
Sánchez-Fernández
Rocío
R
Forde
Brian G
BG
Palmgren
Michael G
MG
Rea
Philip A
PA
Williams
Lorraine E
LE
Sanders
Dale
D
Amtmann
Anna
A
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D001692:Biological Transport; D002118:Calcium / Q000494:pharmacology; D002412:Cations / Q000493:pharmacokinetics*; D017343:Genes, Plant; D016623:Ion Pumps / Q000235:genetics / Q000502:physiology*; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D018517:Plant Roots / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012965:Sodium Chloride / Q000494:pharmacology; D014158:Transcription, Genetic / Q000235:genetics*
D029681:Arabidopsis Proteins; D002412:Cations; D016623:Ion Pumps; D012965:Sodium Chloride; D011188:Potassium; D002118:Calcium