NO调节花粉管生长过程中胞内外Ca2+的变化和细胞壁构建
关键词:NO;钙离子内流(Calcium influx);花粉管(Pollen tube);细胞壁(Cell wall);非损伤微测技术(SIET)。
参考文献:Wang Yuhua, New Phytologist, 2009, 182: 851-862
全文下载:http://dmdb.ibcas.ac.cn/ljx文章/New%20Phytologist%20WANG%20YUHUA.pdf
Summary
• Nitric oxide (NO) plays a key role in many physiological
processes in plants, including pollen tube growth. Here, effects of NO
on extracellular Ca2+ flux and microfilaments during cell wall construction in Pinus bungeana pollen tubes were investigated.
• Extracellular Ca2+ influx, the intracellular Ca2+
gradient, patterns of actin organization,vesicle trafficking and cell
wall deposition upon treatment with the NO donor
S-nitroso-N-acetylpenicillamine (SNAP), the NO synthase (NOS) inhibitor
Nω-nitro-L-arginine(L-NNA) or the NO scavenger 2-(4-carboxyphenyl)-4, 4,
5, 5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) were analyzed.
•
SNAP enhanced pollen tube growth in a dose-dependent manner, while L-NNA
and cPTIO inhibited NO production and arrested pollen tube growth.
Noninvasive detection and microinjection of a Ca2+ indicator revealed that SNAP promoted extracellular Ca2+ influx and increased the steepness of the tip-focused Ca2+
gradient, while cPTIO and L-NNA had the opposite effect. Fluorescence
labeling indicated that SNAP, cPTIO and L-NNA altered actin
organization, which subsequently affected vesicle trafficking. Finally,
the configuration and/or distribution of cell wall components such as
pectins and callose were significantly altered in response to L-NNA.
Fourier transform infrared (FTIR) microspectroscopy confirmed the
changes in the chemical composition of walls.
• Our results indicate
that NO affects the configuration and distribution of cell wall
components in pollen tubes by altering extracellular Ca2+ influx and
F-actin organization.