title: Tapetum degeneration retardation is critical for aliphatic metabolism and gene regulation during rice pollen development.
abstract: As a complex wall system in flowering plants, the pollen outer wall mainly contains aliphatic sporopollenin; however, the mechanism for synthesizing these lipidic precursors during pollen development remains less well understood. Here, we report on the function of the rice tapetum-expressing TDR (Tapetum Degeneration Retardation) gene in aliphatic metabolism and its regulatory role during rice pollen development. The observations of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses suggested that pollen wall formation was significantly altered in the tdr mutant. The contents of aliphatic compositions of anther were greatly changed in the tdr mutant revealed by GC-MS (gas chromatography-mass spectrometry) testing, particularly less accumulated in fatty acids, primary alcohols, alkanes and alkenes, and an abnormal increase in secondary alcohols with carbon lengths from C29 to C35 in tdr. Microarray data revealed that a group of genes putatively involved in lipid transport and metabolism were significantly altered in the tdr mutant, indicating the critical role of TDR in the formation of the pollen wall. Also, a wide range of genes (236 in total-154 up-regulated and 82 down-regulated) exhibited statistically significant expressional differences between wild-type and tdr. In addition to its function in promoting tapetum PCD, TDR possibly plays crucial regulatory roles in several basic biological processes during rice pollen development.
authors.affiliation: Shanghai Jiao Tong University, Shanghai Institutes for Biological Sciences, China.
authors.forename: Da-Sheng
authors.initials: DS
authors.lastname: Zhang
authors.forename: Wan-Qi
authors.initials: WQ
authors.lastname: Liang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yuan
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Shi
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Liu
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Yu
authors.forename: Da-Bing
authors.initials: DB
authors.lastname: Zhang
mesh_terms: D017209:Apoptosis / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D050356:Lipid Metabolism / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000166:cytology / Q000235:genetics* / Q000378:metabolism* / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011058:Pollen / Q000235:genetics* / Q000254:growth & development* / Q000648:ultrastructure; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000235:genetics
chemical_list: D010940:Plant Proteins