Pleiotropic changes in Arabidopsis f5h and sct mutants revealed by  large-scale gene expression and metabolite analysis.
Hydrocinnamic acid esters, lignin, flavonoids, glucosinolates, and salicylic acid protect plants against UV exposure, oxidative stress, diseases, and herbivores. Through the phenylpropanoid pathway, certain Brassicaceae family members, including Arabidopsis thaliana and Brassica napus, accumulate large amounts of the anti-nutritive sinapoylcholine (sinapine) in the seed. We successfully down-regulated activities of key enzymes in the pathway including F5H and SCT and achieved reduction of sinapine and lignin in B. napus seeds. Despite this success, it was unclear how multiple agronomic traits were affected in the transgenic plants. Here, we report altered large-scale gene expression of new alleles of f5h and sct mutants of A. thaliana and resultant accumulation of sinapoylglucose, disinapoylglucose, quercetin-3-O-rhamnoside, salicylic acid glucoside, and total indolyl glucosinolates in the two mutants. Expression of several flowering genes was altered in these mutants when grown under drought and NaCl treatments. Furthermore, both mutants were more susceptible to fungal infection than the wild type. Microarray experiments identified distinctive spatial and temporal expression patterns of gene clusters involved in silique/seed developmental processes and metabolite biosynthesis in these mutants. Taken together, these findings suggest that both f5h and sct mutants exhibit major differences in accumulation of diverse metabolites in the seed and profound changes in global large-scale gene expression, resulting in differential pleiotropic responses to environmental cues. Electronic supplementary material The online version of this article (doi:10.1007/s00425-009-1007-2) contains supplementary material, which is available to authorized users.
Huang
Jun
J
Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK, Canada
Bhinu
V-S
VS
Li
Xiang
X
Dallal Bashi
Zafer
Z
Zhou
Rong
R
Hannoufa
Abdelali
A
D000217:Acyltransferases / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D005658:Fungi / Q000187:drug effects / Q000502:physiology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005960:Glucosides / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D055442:Metabolome / Q000187:drug effects; D009154:Mutation / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010636:Phenols / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D010936:Plant Extracts / Q000032:analysis; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000382:microbiology; D011794:Quercetin / Q000031:analogs & derivatives / Q000378:metabolism; D015203:Reproducibility of Results; D012459:Salicylates / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects
D029681:Arabidopsis Proteins; D005960:Glucosides; D010636:Phenols; D010936:Plant Extracts; D012459:Salicylates; C084746:salicylic acid glucoside; C012526:quercitrin; D012965:Sodium Chloride; D003577:Cytochrome P-450 Enzyme System; D011794:Quercetin; C097486:CYP84A1 protein, Arabidopsis; D000217:Acyltransferases; C079635:sinapoylglucose-choline O-sinapoyltransferase