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Reactive oxygen species produced by NADPH oxidase are involved in pollen tube growth
Author(s) -
Potocký Martin,
Jones Mark A.,
Bezvoda Radek,
Smirnoff Nicholas,
Žárský Viktor
Publication year - 2007
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2007.02042.x
Subject(s) - pollen tube , nadph oxidase , reactive oxygen species , pollen , nox , superoxide , hydrogen peroxide , chemistry , biochemistry , oxidase test , microbiology and biotechnology , biophysics , botany , biology , enzyme , pollination , organic chemistry , combustion
Summary• Tip‐localized reactive oxygen species (ROS) were detected in growing pollen tubes by chloromethyl dichlorodihydrofluorescein diacetate oxidation, while tip‐localized extracellular superoxide production was detected by nitroblue tetrazolium (NBT) reduction. • To investigate the origin of the ROS we cloned a fragment of pollen specific tobacco NADPH oxidase (NOX) closely related to a pollen specific NOX from Arabidopsis . Transfection of tobacco pollen tubes with NOX‐specific antisense oligodeoxynucleotides (ODNs) resulted in decreased amount of NtNOX mRNA, lower NOX activity and pollen tube growth inhibition. • The ROS scavengers and the NOX inhibitor diphenylene iodonium chloride (DPI) inhibited growth and ROS formation in tobacco pollen tube cultures. Exogenous hydrogen peroxide (H 2 O 2 ) rescued the growth inhibition caused by NOX antisense ODNs. Exogenous CaCl 2 increased NBT reduction at the pollen tube tip, suggesting that Ca 2+ increases the activity of pollen NOX in vivo . • The results show that tip‐localized ROS produced by a NOX enzyme is needed to sustain the normal rate of pollen tube growth and that this is likely to be a general mechanism in the control of tip growth of polarized plant cells.