Inhibition of pollen tube elongation by microinjected anti-Rop1Ps antibodies suggests a crucial role for Rho-type GTPases in the control of tip growth
Inhibition of pollen tube elongation by microinjected anti-Rop1Ps antibodies suggests a crucial role for Rho-type GTPases in the control of tip growth
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DOI：
10.1105/tpc.9.9.1647
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发表时间：
1997-09-01
期刊：
影响因子：
11.6
通讯作者：
Yang, ZB
中科院分区：
文献类型：
--
作者：
Lin, YK;Yang, ZB
采用微量注射抗rop1ps抗体的方法来评估顶端定位的rho型GTPase Rep在控制花粉管生长中的作用。注射的抗体在注射后1至2分钟内诱导持续生长停滞，但不影响细胞质流动。与Rop共注射可挽救抗体诱导的生长抑制，表明注射的抗体特异性阻断Rop gtpase的活性。在细胞外[Ca2+]阈值较低或亚抑制剂量的咖啡因存在时，抗体诱导的抑制作用显着增强。相比之下，注射C3毒素，使另一种rho型GTPase失活，在注射后10至20分钟阻止了管的伸长。c3诱导的生长停滞伴随着细胞质流动的停止。这些数据表明rho型gtpase在花粉管伸长的控制中起关键作用。我们提出Rop可能调节参与囊泡对接/融合的Ca2+依赖性途径，而c3敏感的Rho GTPase可能介导细胞质流动。
Microinjection of anti-Rop1Ps antibodies was used to assess the function of a tip-localized Rho-type GTPase, Rep, in controlling pollen tube growth. Injected antibodies induced sustained growth arrest within 1 to 2 min after injection but did not affect cytoplasmic streaming. Coinjection with Rop rescued antibody-induced growth inhibition, indicating that injected antibodies specifically block the activity of Rop GTPases. Antibody-induced inhibition was significantly enhanced in the presence of a lower threshold of extracellular [Ca2+] or a subinhibitory dosage of caffeine. In contrast, injection of the C3 toxin, which inactivates a different Rho-type GTPase, arrested tube elongation 10 to 20 min after injection. C3-induced growth arrest was accompanied by the cessation of cytoplasmic streaming. These data suggest that Rho-type GTPases play a pivotal role in the control of pollen tube elongation. We propose that Rop may regulate a Ca2+-dependent pathway involved in vesicle docking/fusion, whereas a C3-sensitive Rho GTPase may mediate cytoplasmic streaming.