Host: The Japanese Society of Plant Physiologists
Pages 0266
The amyloplasts sedimentation in the endodermal cells is important for gravity perception in Arabidopsis shoot. It has been reported that amyloplasts are surrounded by actin microfilaments (MFs), and that treatment with actin polymerization inhibitor enhances gravitropic organ curvature. However, not only the molecular link between amyolplasts and MFs, but also regulatory role of MFs in gravitropic response is still unclear.
Our previous study suggests that SGR5(SHOOT GRAVITROPISM5) and SGR9 are synergistically involved in regulation of amyloplast movement, and shows that sgr5 sgr9 double mutant completely loses gravitropic response. Here we found that treatment with actin polymerization inhibitor restored gravitropic response of sgr5 sgr9 double mutant stems. The result suggests that abnormal amyloplasts movement in the double mutant could result from inhibition of MFs depolymerization, leading to abnormal gravitropism. We are investigating whether SGR5 and SGR9 are involved in amyloplasts movement by regulating actin remodeling in gravity perceptive cells.
