Ratio‐imaging of Ca²⁺_i in the self‐incompatibility response in pollen tubes of <i>Papaver rhoeas</i>

• Vernonica E. Franklin‐Tong

• Grant Hackett

• Peter K. Hepler

抄録

The data presented here describe ratio‐imaging of in intracellular free calcium (Ca 2+ i) during the self‐incompatibility (SI) response in pollen. Use of the ratiometric indicator, fura‐2 dextran, in pollen tubes of Papaver rhoeas has provided new, detailed information about the spatial‐temporal alterations in Ca 2+ i , and has permitted calibration of alterations in the concentration of intracellular free calcium ([Ca 2+ ] i ) in the SI response. Ratio images demonstrate that, like other pollen tubes, normally growing P. rhoeas pollen tubes exhibit a tip‐focused gradient of Ca 2+bf i , with levels reaching 1–2 μM at the extreme apex of the pollen tube. Non‐growing pollen tubes did not exhibit this tip‐focused gradient. Basal levels of Ca 2+ i in the shank of the pollen tube were fairly consistent and had a mean value of 210 nM, with low‐level fluctuations +/− 50 nM observed. Challenge with incompatible S proteins resulted in S‐specific, rapid and dramatic alterations in [Ca 2+ ] i within a few seconds of challenge. Increases in [Ca 2+ ] i were visualized in the subapical/shank regions of the pollen tube and alterations in [Ca 2+ ] i in this region subsequently increased for several minutes, reaching> 1.5 μM. At the pollen tube tip, a diminution of the tip‐focused gradient was observed, which following some fluctuation, was reduced to basal levels within ∼1 min. Our data suggest that some of these alterations in [Ca 2+ ] i might be interpreted as a calcium wave, as the changes are not global. Although the increases in [Ca 2+ ] i in the subapical/shank region are very rapid, because tip [Ca 2+ ] i oscillates during normal growth, it is difficult to ascertain whether the increases in the shank of the pollen tube precede the decreases in [Ca 2+ ] i at the pollen tube tip.

収録刊行物

• The Plant Journal

  The Plant Journal 12 (6), 1375-1386, 1997-12

  Wiley

キーワード

• Cell Biology
• Plant Science
• Genetics

詳細情報

• CRID: 1361699994611813376
• NII論文ID: 30014608004
• DOI: 10.1046/j.1365-313x.1997.12061375.x
• ISSN: 1365313X
• ISSN: 09607412
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-313x.1997.12061375.x
• Web Site: https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-313x.1997.12061375.x
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  • CiNii Articles