2014-09-29

Events in plant lipid metabolism are important during seedling establishment. As it has not been experimentally verified whether lipid metabolism in 2- and 5-day-old Arabidopsis thaliana seedlings is diurnally-controlled, quantitative real-time PCR analysis was used to investigate the expression of target genes in acyl-lipid transfer, β-oxidation and triacylglycerol (TAG) synthesis and hydrolysis in wild-type Arabidopsis WS and Col-0. In both WS and Col-0, ACYL-COA-BINDING PROTEIN3 (ACBP3), DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) and DGAT3 showed diurnal control in 2- and 5-day-old seedlings. Also, COMATOSE (CTS) was diurnally regulated in 2-day-old seedlings and LONG-CHAIN ACYL-COA SYNTHETASE6 (LACS6) in 5-day-old seedlings in both WS and Col-0. Subsequently, the effect of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) from the core clock system was examined using the cca1lhy mutant and CCA1-overexpressing (CCA1-OX) lines versus wild-type WS and Col-0, respectively. Results revealed differential gene expression in lipid metabolism between 2- and 5-day-old mutant and wild-type WS seedlings, as well as between CCA1-OX and wild-type Col-0. Of the ACBPs, ACBP3 displayed the most significant changes between cca1lhy and WS and between CCA1-OX and Col-0, consistent with previous reports that ACBP3 is greatly affected by light/dark cycling. Evidence of oil body retention in 4- and 5-day-old seedlings of the cca1lhy mutant in comparison to WS indicated the effect of cca1lhy on storage lipid reserve mobilization. Lipid profiling revealed differences in primary lipid metabolism, namely in TAG, fatty acid methyl ester and acyl-CoA contents amongst cca1lhy, CCA1-OX, and wild-type seedlings. Taken together, this study demonstrates that lipid metabolism is subject to diurnal regulation in the early stages of seedling development in Arabidopsis.

Hsiao, AS, Haslam, RP, Michaelson, LV, Liao, P, Napier, JA, Chye, ML. (2014). Data from: Gene Expression in Plant Lipid Metabolism in Arabidopsis Seedlings. [Data File]. The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are within the paper and its Supporting Information files. Click on “Linked Publications” to access the publication and access supporting information on figshare at https://figshare.com/articles/_Gene_Expression_in_Plant_Lipid_Metabolism_in_Arabidopsis_Seedlings_/1185861

LATE ELONGATED HYPOCOTYL

LACS

ws

cca

plant lipid metabolism

cts

synthetase

tag

protein

CIRCADIAN CLOCK ASSOCIATED 1

acid methyl ester

Arabidopsis thaliana seedlings

lhy

acyltransferase

cca 1lhy

comatose

pcr

Arabidopsis Seedlings Events

storage lipid reserve mobilization

gene

Lipid metabolism

dgat

core clock system

oil body retention

diacylglycerol

ACBP 3

col