Figure 3.

Nod factor, chitotetraose, and xylanase stimulate PA and PIP₂ turnover in suspension-cultured alfalfa cells. A, Nod factor, chitotetraose, and xylanase stimulate PA formation. Cells were prelabeled with ³²P_i for just 15 min before stimulating them with 10⁻⁹ m Nod factor, 10⁻⁹ m chitotetraose, or 200 μg mL⁻¹ xylanase for different periods of time. As a control, cells were treated with conditioned growth medium. Treatment was stopped, and lipids were extracted and then separated by alkaline TLC. The amount of radioactive PA was quantified by phosphor imaging and expressed as -fold stimulation in relation to time 0. B, Nod factor, chitotetraose, and xylanase induce changes in the level of PIP₂. Cells were prelabeled with ³²P_i for just 15 min before stimulating them with 10⁻⁹ m Nod factor, 10⁻⁹ m chitotetraose, or 200 μg mL⁻¹ xylanase for different periods of time. As a control, cells were treated with conditioned medium. Treatment was stopped, and the lipids were extracted and separated by alkaline TLC. The amount of radioactive PIP₂ was quantified by phosphor imaging and expressed as -fold stimulation in relation to time 0.