BoPMEI1, a pollen-specific pectin methylesterase inhibitor, has an essential role in pollen tube growth.
Pectin methylesterase (PME) is known to have important roles in pollen development and pollen tube growth. As pivotal regulatory factors in PME activity modulation, PME inhibitors (PMEIs) are thought to be key regulators of cell wall stability at the tip of the pollen tube. We report on the cloning and characterization of a novel B. oleracea PMEI gene, BoPMEI1. Heterologously expressed BoPMEI1 showed PMEI activity. RT-PCR studies of different tissues and promoter-GUS fusions confirmed that BoPMEI1 was specifically expressed in mature pollen grains and pollen tubes. Based on in vivo transient assays, we found that BoPMEI1 appears to be largely localized to the plasma membrane. Transgenic Arabidopsis plants expressing antisense BoPMEI1 under the control of the CaMV 35S promoter suppressed the expression of the orthologous gene At1g10770, which led to partial male sterility and decreased seed set by inhibition of pollen tube growth. Our study demonstrates the involvement of BoPMEI1 in pollen tube growth.
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, 12 Zhongguancun Nandajie, Beijing 100081, People's Republic of China.
Guo Yu
GY
Zhang
Jing
J
Feng
Jian
J
Wu
Xiao Wu
XW
Wang
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics; D001483:Base Sequence; D001937:Brassica / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018525:Germination; D005966:Glucuronidase / Q000378:metabolism; D007613:Kanamycin Resistance / Q000235:genetics; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010641:Phenotype; D051479:Plant Infertility; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D053205:Pollen Tube / Q000166:cytology / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism*; D017433:Protein Structure, Secondary; D021381:Protein Transport; D016372:RNA, Antisense / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000254:growth & development
D004791:Enzyme Inhibitors; D010940:Plant Proteins; D016372:RNA, Antisense; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase; D005966:Glucuronidase