Kelch-motif containing acyl-CoA binding proteins AtACBP4 and AtACBP5 are differentially expressed and function in floral lipid metabolism

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• 作者：Zi-Wei Ye ; Jie Xu ; Jianxin Shi ; Dabing Zhang ; Mee-Len Chye
• 关键词：Acyl ; CoA ; binding protein ; Arabidopsis thaliana ; Lipid metabolism ; Pollen ; POLLEN1 ; Pollen tube
• 刊名：Plant Molecular Biology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：93
• 期：1-2
• 页码：209-225
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Plant Sciences; Biochemistry, general; Plant Pathology;
• 出版者：Springer Netherlands
• ISSN：1573-5028
• 卷排序：93

文摘

Key messageWe herein demonstrated two of the Arabidopsis acyl-CoA-binding proteins (ACBPs), AtACBP4 and AtACBP5, both function in floral lipid metabolism and they may possibly play complementary roles in Arabidopsis microspore-to-pollen development. Histological analysis on transgenic Arabidopsis expressing β-glucuronidase driven from the AtACBP4 and AtACBP5 promoters, as well as, qRTPCR analysis revealed that AtACBP4 was expressed at stages 11–14 in the mature pollen, while AtACBP5 was expressed at stages 7–10 in the microspores and tapetal cells. Immunoelectron microscopy using AtACBP4- or AtACBP5-specific antibodies further showed that AtACBP4 and AtACBP5 were localized in the cytoplasm. Chemical analysis of bud wax and cutin using gas chromatographyflame ionization detector and GC-mass spectrometry analyses revealed the accumulation of cuticular waxes and cutin monomers in acbp4, acbp5 and acbp4acbp5 buds in comparison to the wild type (Col-0). Fatty acid profiling demonstrated a decline in stearic acid and an increase in linolenic acid in acbp4 and acbp4acbp5 buds, respectively, over Col-0. Analysis of inflorescences from acbp4 and acbp5 revealed that there was an increase of AtACBP5 expression in acbp4, and an increase of AtACBP4 expression in acbp5. Deletion analysis of the AtACBP4 and AtACBP5 5′-flanking regions indicated the minimal promoter activity for AtACBP4 (−145/+103) and AtACBP5 (−181/+81). Electrophoretic mobility shift assays identified a pollen-specific cis-acting element POLLEN1 (AGAAA) mapped at AtACBP4 (−157/−153) which interacted with nuclear proteins from flower and this was substantiated by DNase I footprinting.